WEBVTT - Ep 84 West Nile virus: The Crow in the Coal Mine 0:00:01.920 --> 0:00:04.680 My name is Reagan, and I grew up in a 0:00:04.760 --> 0:00:08.320 very small town. I had exactly seventeen people in my 0:00:09.240 --> 0:00:11.719 high school graduation, so I just wanted to set the 0:00:11.720 --> 0:00:15.560 stage of what I was dealing with in the medical community. 0:00:16.960 --> 0:00:19.520 When I was sixteen, my school was getting ready for 0:00:19.560 --> 0:00:22.320 homecoming and we were the last class they got to 0:00:22.360 --> 0:00:25.040 have a bonfire at ours, so we really wanted to 0:00:25.079 --> 0:00:28.240 go all out for everyone, not just for us. And 0:00:28.320 --> 0:00:31.040 I really wasn't big on the outdoors. I wasn't an 0:00:31.080 --> 0:00:34.240 outside fan. I didn't like wearing the long sleeves, the pants, 0:00:34.240 --> 0:00:38.239 the mosquito's fright. But I worked hard for this and 0:00:38.280 --> 0:00:41.920 it was an amazing bonfire. It was actually only a 0:00:41.960 --> 0:00:44.360 few days later that I was spending and linking with 0:00:44.360 --> 0:00:48.760 my grandmother, and right after school I came down with 0:00:48.840 --> 0:00:52.839 a headache and I wasn't interested in watching TV. I 0:00:52.880 --> 0:00:56.800 wasn't interested in eating dinner. I even went to bed 0:00:56.880 --> 0:01:00.400 before the sunset. And my grandmother was really increasing worried 0:01:00.440 --> 0:01:03.480 over this behavior. She was checking on me every half hour. 0:01:03.960 --> 0:01:06.040 She wanted to take me to the er, but she knew, 0:01:06.200 --> 0:01:07.880 especially in time my cars, that they were just going 0:01:07.920 --> 0:01:11.400 to send me home with tile at all. So then 0:01:11.400 --> 0:01:14.920 the fever hit, and when it hit, it came on 0:01:15.360 --> 0:01:18.880 hard and fast, and my grandmother called the hospital, who 0:01:18.920 --> 0:01:20.600 said that all they would do was put me in 0:01:20.600 --> 0:01:23.679 an icepath and send me home. That was their fever protocol. 0:01:24.840 --> 0:01:27.720 So she called my mom, who was a five hour 0:01:27.840 --> 0:01:31.160 dRIT away, and all I remember her saying is something 0:01:31.200 --> 0:01:34.080 isn't right. I think you need to come home. She'd 0:01:34.080 --> 0:01:37.360 been gone for school, she'd been with a friend. She 0:01:37.400 --> 0:01:39.920 didn't even have her own car, but something in my 0:01:39.959 --> 0:01:43.840 grandmother's voice convinced her, so she rented it something. She 0:01:43.959 --> 0:01:46.920 came home, and by the time that the fever got 0:01:47.000 --> 0:01:48.840 so bad that she was having to lay on me 0:01:49.040 --> 0:01:52.600 to keep the chills from shaking the bed, she decided 0:01:52.600 --> 0:01:55.400 she was done. We were going to the er. I 0:01:55.480 --> 0:01:59.280 don't really remember much from them now it gets really hazy. 0:02:00.560 --> 0:02:04.920 I remember being super uncomfortable. I remember begging my mom 0:02:05.000 --> 0:02:09.799 to go home. I just wanted my bed. I wanted 0:02:09.800 --> 0:02:13.400 to sleep. The doctors were asking me to do all 0:02:13.440 --> 0:02:16.359 these things that I couldn't do. I couldn't stand up, 0:02:16.880 --> 0:02:19.880 I couldn't stay conscious, and they were asking me to 0:02:20.120 --> 0:02:23.720 touch my chin to my chest and I couldn't do 0:02:23.760 --> 0:02:27.680 it it hurts so bad. And that's when things started 0:02:27.680 --> 0:02:31.720 to get scary. I didn't know until later that they 0:02:31.760 --> 0:02:34.440 told my family that I was going to die. And 0:02:34.520 --> 0:02:37.960 I was like in the room, like laying on the bed, 0:02:38.200 --> 0:02:41.000 and my mother demanded that i'd be moved to the 0:02:41.000 --> 0:02:43.280 hospital that was in the bigger city. It was an 0:02:43.360 --> 0:02:46.280 hour away, and they said that I wouldn't make it. 0:02:47.680 --> 0:02:50.280 And then there was one doctor who came into the 0:02:50.360 --> 0:02:52.880 room said he was giving me an ambulance and that 0:02:52.960 --> 0:02:56.200 he would have a friend waiting for my arrival because 0:02:56.240 --> 0:02:59.040 he was very scared that this was something very serious. 0:03:00.480 --> 0:03:03.200 Everything after that kind of comes in flashes. I remember 0:03:03.240 --> 0:03:05.520 the night sky becoming the roof of an ambulance. I 0:03:05.560 --> 0:03:08.440 remember my mother's face while she stroked my hair. I 0:03:08.480 --> 0:03:10.680 remember being pulled away from her so they could do 0:03:10.680 --> 0:03:13.080 a spinal tap, which was the scariest thing that's ever 0:03:13.200 --> 0:03:17.000 happened to me in my entire life. I remember too 0:03:17.000 --> 0:03:19.200 many hands on me while they moved me to a stretcher. 0:03:19.639 --> 0:03:22.000 I remember my father arriving, which was like a big 0:03:22.040 --> 0:03:25.160 deal of My dad actually came to a hospital, and 0:03:25.440 --> 0:03:28.960 I remembered my pediatrician because I had been so healthy 0:03:29.320 --> 0:03:31.720 up into my teen years that I hadn't actually acquired 0:03:31.760 --> 0:03:35.400 a GP yet. I remember hazard suits because I didn't 0:03:35.440 --> 0:03:38.480 actually know if what I had was bacterial or viral. 0:03:38.960 --> 0:03:41.440 I was so dehydrated that they blew my vein trying 0:03:41.440 --> 0:03:43.720 to give me IVS. I was still maninurish that I 0:03:43.760 --> 0:03:46.800 lost fifteen pounds in the hospital. I was so weak 0:03:46.840 --> 0:03:48.640 that I had to relearn how to walk, and I 0:03:48.680 --> 0:03:50.880 remember thinking that I was going to die, and I 0:03:51.000 --> 0:03:54.000 was okay with that, and it was actually well before 0:03:54.280 --> 0:03:59.880 the results came in West nilmanuingitis. I missed two weeks 0:04:00.040 --> 0:04:03.640 of school between treatment and recovery. It took even longer 0:04:04.080 --> 0:04:06.640 to return to normal, and my classmates had to help 0:04:06.680 --> 0:04:10.200 me carry things between classes because the locks were too 0:04:10.240 --> 0:04:13.120 long and my body was too exhausted. And I remember 0:04:13.240 --> 0:04:16.680 my teacher was giving me gift baskets and extensions on 0:04:16.720 --> 0:04:19.719 my homework, and my family members made me homemade cine 0:04:19.760 --> 0:04:22.320 mem roles. He gave my weight back, And it didn't 0:04:22.320 --> 0:04:25.720 occur to me until much later that everyone was doing 0:04:25.760 --> 0:04:29.800 this because I wasn't supposed to make it. Everyone had 0:04:29.880 --> 0:04:32.160 said that I was going to die. Preparations had been 0:04:32.160 --> 0:04:34.719 made at the school for me to not come back, 0:04:35.400 --> 0:04:38.279 and because I did, nobody wanted to let me research 0:04:38.480 --> 0:04:41.400 what had almost killed me. They waited patiently for my 0:04:41.400 --> 0:04:45.120 obsession with it to disappear, and it did until I 0:04:45.120 --> 0:04:46.760 started listening to your podcasts. 0:04:47.320 --> 0:05:36.719 That's well, thank you so much, Reagan for taking the 0:05:36.800 --> 0:05:38.600 time to tell your story. 0:05:39.520 --> 0:05:41.400 Wow, I mean what a story. 0:05:41.640 --> 0:05:45.320 Yeah, thank you, it's absolutely terrifying. 0:05:45.440 --> 0:05:49.680 Yeah, seriously. Yeah. 0:05:49.720 --> 0:05:52.599 Well, Hi, I'm Erin Welsh. 0:05:52.040 --> 0:05:55.480 And I'm Erin Allman Updyke and this is this podcast 0:05:55.560 --> 0:06:00.159 will kill you. Welcome to West Now Virus. Welcome to 0:06:00.160 --> 0:06:01.120 West Style Virus. 0:06:01.279 --> 0:06:06.679 And what is our second to last episode of this season? 0:06:07.040 --> 0:06:09.520 I really truly can't believe that we've made it this far. Erin, 0:06:11.360 --> 0:06:12.760 I'm going to be completely honest. 0:06:13.040 --> 0:06:17.520 I mean same and yeah, so we are after the 0:06:17.680 --> 0:06:20.800 end of this season, so not this episode, but the 0:06:20.800 --> 0:06:22.680 one after will be the last of the season. 0:06:22.960 --> 0:06:24.440 We're going to be taking a short break. 0:06:24.560 --> 0:06:26.280 Don't worry, we won't be gone forever. 0:06:27.400 --> 0:06:29.279 We'll be back. We'll be back. 0:06:29.360 --> 0:06:32.240 So you know, make sure that you're subscribed to the 0:06:32.320 --> 0:06:35.719 podcast to all of our social media so you know 0:06:35.760 --> 0:06:38.200 what we're doing in the break and also when we're 0:06:38.200 --> 0:06:39.520 coming out with a new episode. 0:06:39.839 --> 0:06:42.920 Yeah, or any other fun surprises that could happen. Who knows. 0:06:42.960 --> 0:06:45.599 We don't know. Anything could happen. Anything could happen. 0:06:47.960 --> 0:06:51.400 But yeah, West Nile, Aaron, this is our first mosquito 0:06:51.480 --> 0:06:52.599 born one of this season. 0:06:52.680 --> 0:06:53.200 Is that right? 0:06:53.640 --> 0:06:54.360 Is it? 0:06:54.720 --> 0:06:58.120 I guess it is. I'm going to be totally honest 0:06:58.200 --> 0:07:00.440 this season, I don't even remember what things we've done. 0:07:00.440 --> 0:07:03.160 I know we did shagus, so I know that was 0:07:03.200 --> 0:07:04.520 a vector Boyne disease. 0:07:05.120 --> 0:07:09.120 I'm just also surprised that we hadn't done West Nile yet, Like, 0:07:09.160 --> 0:07:11.080 this is a this is kind of a big deal. 0:07:11.280 --> 0:07:15.080 Oh, Aaron, you could just play a broken record of 0:07:15.200 --> 0:07:17.560 us in our intros saying the exact same thing for 0:07:17.640 --> 0:07:18.760 every single episode. 0:07:19.960 --> 0:07:20.200 It is. 0:07:20.600 --> 0:07:21.800 It is true. 0:07:23.200 --> 0:07:26.600 Oh man, It's gonna be a good episode though. 0:07:26.920 --> 0:07:29.640 It is for a number of reasons. So you just 0:07:29.720 --> 0:07:33.880 heard that incredible first hand account. And we have another 0:07:34.040 --> 0:07:37.680 fantastic guest lined up for this episode to help shed 0:07:37.760 --> 0:07:43.000 some light on the ecology of West Nile virus. And 0:07:43.760 --> 0:07:47.840 one of the most exciting things you have to stay 0:07:47.840 --> 0:07:52.240 tuned for the very very end of the episode, and 0:07:52.280 --> 0:07:58.280 that's because there is a West Nile rap al rap 0:07:58.600 --> 0:08:02.680 It is called West Nile Story and it is by 0:08:03.080 --> 0:08:09.560 friend of the podcast mc bugsy, who made it in 0:08:09.760 --> 0:08:14.400 collaboration with the Fairfax County Health Department working in the 0:08:14.440 --> 0:08:17.960 Disease Carrying Insects program Fairfax County, Virginia. 0:08:18.000 --> 0:08:19.000 I had to look that up. 0:08:19.240 --> 0:08:21.280 I am so excited for everyone to hear it. 0:08:21.880 --> 0:08:22.600 Oh my gosh. 0:08:22.720 --> 0:08:26.960 So it is absolutely a fantastic song. And not only that, 0:08:27.200 --> 0:08:30.520 like this is not mc bugsy's only song, So make 0:08:30.560 --> 0:08:33.679 sure you go to YouTube. We'll provide a link, don't worry, 0:08:33.920 --> 0:08:36.160 and you can check out all of the raps. There's 0:08:36.200 --> 0:08:37.840 even one about COVID vaccines. 0:08:37.880 --> 0:08:44.360 It is incredible, awesome. Well and speaking of classic TPWKY, 0:08:44.760 --> 0:08:48.800 it's about time for quarantiney. 0:08:47.720 --> 0:08:50.280 It is what are we drinking this week? 0:08:50.400 --> 0:08:54.040 We're drinking for the birds. 0:08:54.600 --> 0:08:58.400 Which, like we want to make sure that you know, 0:08:58.480 --> 0:09:01.560 it's for the opposite of the reason that people. 0:09:01.400 --> 0:09:02.920 Usually say for the birds. 0:09:03.200 --> 0:09:07.079 We wanted to name it this to honor the birds. 0:09:07.640 --> 0:09:09.120 It's for the bird. 0:09:09.280 --> 0:09:12.240 It is for the birds. This is for the birds. 0:09:12.280 --> 0:09:12.920 Can we say it? 0:09:13.480 --> 0:09:14.920 What is in for the birds? 0:09:15.040 --> 0:09:18.559 Erin so for the birds is actually based on an 0:09:18.600 --> 0:09:22.680 existing cocktail also named after a bird called the yellow 0:09:22.720 --> 0:09:23.559 Bird cocktail. 0:09:23.840 --> 0:09:26.040 Very apt, very apt it is. 0:09:25.960 --> 0:09:29.679 And that is made with white rum, orange liqueur galiano 0:09:29.960 --> 0:09:31.080 and lime juice. 0:09:31.679 --> 0:09:32.520 Delish. 0:09:32.640 --> 0:09:34.520 It is tart and delish. 0:09:34.679 --> 0:09:37.720 We'll post a full recipe for that quarantini as well 0:09:37.760 --> 0:09:40.800 as our non alcoholic plasy Bereta on our website This 0:09:40.840 --> 0:09:43.079 Podcast will kill You dot Com and all of our 0:09:43.080 --> 0:09:44.559 social media channels. 0:09:44.559 --> 0:09:48.800 Absolutely other business website stuff. 0:09:49.080 --> 0:09:52.199 Yeah, always check out our website This podcast will kill 0:09:52.240 --> 0:09:52.960 You dot Com? 0:09:54.200 --> 0:09:55.480 Should we even go through? 0:09:55.559 --> 0:09:57.760 Like what's on the website? I mean everything? Is there 0:09:57.800 --> 0:10:01.200 anything that you could want? It's there? Yeah, it is. 0:10:01.960 --> 0:10:04.520 Should we just get started on this episode? Can we? 0:10:04.679 --> 0:10:06.760 Let's take a quick break and then dive straight in? 0:10:37.960 --> 0:10:43.240 West Nile virus is a flava virus, which listeners of 0:10:43.280 --> 0:10:46.880 this show should be very familiar with by now because 0:10:46.880 --> 0:10:52.240 we've covered so many other flava viruses, right, dange virus, 0:10:52.800 --> 0:10:59.600 yellow fever, hepatitis, see even so many viruses we're running 0:10:59.600 --> 0:11:04.360 out of laviviruses to cover. Just kidding, there's always more, 0:11:05.679 --> 0:11:09.720 but anyways, flaviviruses for anyone who hasn't listened to every 0:11:09.720 --> 0:11:13.840 one of our episodes, is a large family of RNA viruses, 0:11:14.600 --> 0:11:19.320 many of which are transmitted by arthropod vectors to animals 0:11:19.360 --> 0:11:24.720 and humans. West nilevirus causes a disease that primarily is 0:11:24.720 --> 0:11:28.440 what's called enzootic. That is, it has a cycle that 0:11:28.559 --> 0:11:33.080 is completely independent of humans. It's essentially a vector born 0:11:33.120 --> 0:11:37.880 disease of wildlife. This cycle is maintained in nature, specifically 0:11:37.920 --> 0:11:43.319 through an avian mosquito cycle. So birds and mosquitoes, where 0:11:43.880 --> 0:11:48.960 mostly mosquitoes in the genus Qlex feed on avian or 0:11:49.000 --> 0:11:52.400 bird hosts. They pick up the virus in their blood 0:11:52.440 --> 0:11:55.200 meal and then it passes through their gut, makes it 0:11:55.200 --> 0:11:58.280 to the salivary glands, they spit it back out, and 0:11:58.320 --> 0:12:02.240 then transmit it to other birds. And that's the primary cycle. 0:12:02.679 --> 0:12:06.199 Simple enough, Yeah, simple enough, especially compared to a lot 0:12:06.200 --> 0:12:10.160 of things that we cover. Will make it more complicated, 0:12:10.160 --> 0:12:11.000 don't worry. 0:12:11.160 --> 0:12:12.640 Oh yeah. 0:12:12.679 --> 0:12:16.520 It's thought that the virus is able to persist and 0:12:16.640 --> 0:12:21.520 perpetuate even in temperate regions of the world where adult 0:12:21.679 --> 0:12:26.680 mosquitoes aren't present all year round, both via adult mosquitoes 0:12:26.720 --> 0:12:31.040 that undergo diapause, so the virus persists in overwintering adults 0:12:31.040 --> 0:12:34.760 that are just not active. I have also seen that 0:12:34.800 --> 0:12:39.600 it's also possible that adult mosquitoes transmit it transovarially. I 0:12:39.640 --> 0:12:43.640 don't know how common that is, but it's also possible 0:12:43.800 --> 0:12:47.840 that migratory birds play a large role, bringing in virus 0:12:48.000 --> 0:12:51.640 from areas of higher transmission or places where you have 0:12:51.800 --> 0:12:55.920 year round transmission, or even just harboring low levels of virus, 0:12:56.200 --> 0:12:59.640 and then during their migration cycles bringing that virus back 0:12:59.679 --> 0:13:04.600 to temperate areas. But in any case, this avian mosquito 0:13:04.760 --> 0:13:09.560 cycle is the main enzootic cycle of West Nile virus, 0:13:10.760 --> 0:13:15.960 and birds are the predominant reservoir host for Westnile virus 0:13:16.840 --> 0:13:20.880 in North America alone. Hundreds of species of birds have 0:13:20.960 --> 0:13:24.439 been shown to be competent reservoir hosts, so harboring the 0:13:24.520 --> 0:13:27.520 virus whether or not they get sick and show symptoms, 0:13:28.400 --> 0:13:31.760 and the majority of bird species do seem to survive 0:13:31.920 --> 0:13:36.640 infection relatively unscathed. Don't worry, someone else is going to 0:13:36.679 --> 0:13:39.840 talk a lot more about this virus in birds. I'm 0:13:39.840 --> 0:13:44.840 going to focus on this virus in people. But other 0:13:44.920 --> 0:13:50.559 than birds and people, other animals can get infected as well. Importantly, 0:13:51.120 --> 0:13:57.040 horses also get infected relatively frequently, But humans and horses 0:13:57.360 --> 0:14:00.960 are what are called dead end hosts. That means that 0:14:01.040 --> 0:14:04.480 while we can become infected when a mosquito bites us 0:14:04.920 --> 0:14:07.680 and we can get sick, we can get clinical disease. 0:14:08.600 --> 0:14:13.560 Humans and horses don't actually contribute to the cycle of infection, 0:14:14.240 --> 0:14:17.000 so mosquitoes that then feed on us don't tend to 0:14:17.040 --> 0:14:22.120 become infected from feeding on infected people, right, And so 0:14:22.920 --> 0:14:25.160 I am going to focus on this disease as it 0:14:25.200 --> 0:14:28.720 manifests in humans. But like we kind of said upfront, 0:14:28.760 --> 0:14:33.080 it's also very important to understand the ecology and persistence 0:14:33.160 --> 0:14:35.520 of this disease is a lot more complex than just 0:14:35.600 --> 0:14:38.520 the human side of it. So we'll get to that 0:14:38.600 --> 0:14:42.320 and I'm really excited to get to that later. All Right, 0:14:43.200 --> 0:14:46.520 just focusing then on humans, let's talk about what it 0:14:46.560 --> 0:14:51.040 looks like when a person gets West Nile disease. First off, 0:14:51.240 --> 0:14:56.120 it's unclear exactly how infectious West Nile virus is. That is, 0:14:56.240 --> 0:14:59.400 how many people who get bitten by mosquitoes harboring West 0:14:59.440 --> 0:15:03.080 Nile virus actually go on to become infected. We don't 0:15:03.080 --> 0:15:04.360 really know well. 0:15:04.440 --> 0:15:07.520 And I would also imagine that the amount of virus 0:15:08.080 --> 0:15:10.200 varies mosquito to mosquito. 0:15:10.080 --> 0:15:14.880 Definitely absolutely, I would yes. So we really don't know 0:15:14.920 --> 0:15:19.480 what the overall infectiousness of Westnile virus is, but we 0:15:19.560 --> 0:15:23.400 do know that of those people who get infected, about 0:15:23.720 --> 0:15:28.760 twenty five percent some estimates say twenty to forty percent, 0:15:28.840 --> 0:15:31.160 but most that I've seen are around twenty or twenty 0:15:31.160 --> 0:15:36.400 five percent of people will develop symptomatic disease aka West 0:15:36.480 --> 0:15:41.320 Nile fever, and about one in one hundred and fifty 0:15:41.720 --> 0:15:44.800 to two hundred and fifty, or less than one percent 0:15:45.280 --> 0:15:50.080 of those people will develop what's called neuroinvasive disease or 0:15:50.120 --> 0:15:57.360 sometimes it's called WNND Wesnile neuroinvasive disease. And this includes 0:15:57.640 --> 0:16:02.840 one of three possible rologic manifestations that are common. And 0:16:02.880 --> 0:16:06.880 then there's also honestly any range of neurologic complications that 0:16:06.880 --> 0:16:10.720 can happen, but the three big ones are West Nile encephalitis, 0:16:11.440 --> 0:16:16.920 West Nile meningitis, and West Nile acute flaccid paralysis. And 0:16:16.960 --> 0:16:19.560 because I know you're gonna ask me, Aaron, we don't 0:16:19.600 --> 0:16:23.240 fully know why exactly it is that some people get 0:16:23.320 --> 0:16:29.400 invasive disease and others don't. But I know I can 0:16:29.440 --> 0:16:34.600 see you're down trotic face, It's true, we have some ideas. Okay, 0:16:35.280 --> 0:16:38.760 it's likely a combination of that viral load like you 0:16:38.800 --> 0:16:42.000 already mentioned, so how much virus do you get injected 0:16:42.040 --> 0:16:45.200 with from this mosquito to begin with, and then a 0:16:45.280 --> 0:16:49.560 lot of other individual risk factors like older age, especially 0:16:49.600 --> 0:16:53.120 over age sixty five or seventy is very strongly associated 0:16:53.120 --> 0:16:57.080 with increased risk of neuroinvasive disease, and then other things 0:16:57.120 --> 0:17:00.840 like hypertension, kidney disease, things that are affect your overall 0:17:00.840 --> 0:17:07.840 immune status. Also, West Nile virus being a disease transmitted 0:17:07.880 --> 0:17:11.800 by mosquitoes into your bloodstream is a disease that can 0:17:11.840 --> 0:17:15.760 also then potentially be transmitted from things like organ transplants, 0:17:16.720 --> 0:17:20.040 and people who have gotten West Nile infection from things 0:17:20.080 --> 0:17:22.719 like organ transplants are also far more likely to develop 0:17:22.760 --> 0:17:27.760 neuroinvasive disease compared to those that get infected from mosquitoes. Interesting, okay, 0:17:28.480 --> 0:17:33.320 but that is very rare. I'm just saying so. Generally, 0:17:33.680 --> 0:17:37.320 the incubation period for Westnile fever is anywhere from two 0:17:37.440 --> 0:17:41.480 to fourteen days most of the time, and symptoms can 0:17:41.560 --> 0:17:46.560 really range from a pretty mild, almost flu like illness 0:17:47.080 --> 0:17:54.240 to like I mentioned a very debilitating neuroinvasive disease, but 0:17:54.480 --> 0:17:59.600 in most people it often starts like this, a sudden 0:17:59.640 --> 0:18:03.879 onset of headache, very sudden onset of a pretty bad headache, 0:18:04.840 --> 0:18:10.520 generalized malaise, just feeling really crappy, a fever, muscle aches, 0:18:10.880 --> 0:18:15.359 and then fatigue, And very often as this fever starts 0:18:15.359 --> 0:18:19.440 to subside, a rash will develop, usually along the torso 0:18:19.680 --> 0:18:23.040 and then extending out to the arms and legs. And 0:18:23.080 --> 0:18:26.600 this rash actually looks kind of like the rash from measles. 0:18:27.480 --> 0:18:31.160 So it's like what we call maculo popular. It's little red, 0:18:31.480 --> 0:18:36.080 flat little spots with raised little bumps inside. Yeah, it's 0:18:36.119 --> 0:18:38.199 the kind of rash that really like, a lot of 0:18:38.200 --> 0:18:42.280 different viruses cause similar rashes. Unlike measles, this doesn't tend 0:18:42.320 --> 0:18:45.680 to go head down. This is just like a torso 0:18:45.800 --> 0:18:51.600 to extremities type rash. Why why great question? I have 0:18:51.800 --> 0:18:58.880 the slightest idea. Honestly, a lot of viruses cause similar 0:18:58.960 --> 0:19:03.359 rashes like this. So whether it's a combination of the 0:19:03.440 --> 0:19:07.520 damage that that virus is doing to your cells versus 0:19:07.560 --> 0:19:10.400 just that kind of generalized immune response causing that rash, 0:19:10.440 --> 0:19:15.120 I don't know the answer. Yeah, rashes, rashes, let's ask 0:19:15.160 --> 0:19:17.320 a dermologist. I don't know. 0:19:18.480 --> 0:19:22.200 I have a question about the complications the neuroinvasive disease. 0:19:22.240 --> 0:19:23.720 Oh, don't worry, We're going to get there, Aaron. 0:19:24.160 --> 0:19:28.840 Okay, But I'm just the breakdown among them. So you 0:19:28.880 --> 0:19:32.400 mentioned the three different kinds. Yeah, what is the breakdown 0:19:32.480 --> 0:19:32.919 of those? 0:19:32.920 --> 0:19:34.960 That's a good question. I actually don't have a good 0:19:35.040 --> 0:19:37.880 handle on the breakdown everything. Just sort of said less 0:19:37.880 --> 0:19:42.840 than one percent will develop these complications, okay. And part 0:19:42.880 --> 0:19:44.600 of it, I think is probably because there's a bit 0:19:44.640 --> 0:19:46.840 of a spectrum, like it doesn't mean that you maybe 0:19:46.880 --> 0:19:49.560 only have one of the three. You might have some 0:19:49.720 --> 0:19:53.280 acute flaccid paralysis with a little meningitis. You might have 0:19:53.320 --> 0:19:57.520 a meningio encephalitis. Yeah, but that's a good question. Also, 0:19:57.560 --> 0:20:00.360 I think because it is so rare, we probably don't 0:20:00.359 --> 0:20:02.119 have really good numbers to be able to break it 0:20:02.160 --> 0:20:06.119 down when it's less than one percent. Okay, okay, But 0:20:06.200 --> 0:20:12.400 the rash back to that that those type of kind 0:20:12.400 --> 0:20:15.600 of mild symptoms can last anywhere from a handful of 0:20:15.720 --> 0:20:19.040 days to up to a few weeks, So this can 0:20:19.119 --> 0:20:22.800 be a pretty prolonged course of illness, even if it's 0:20:22.920 --> 0:20:29.560 not severe. Now, if it progresses to that narrow invasive disease, 0:20:30.840 --> 0:20:34.920 the symptoms then just kind of look like whatever part 0:20:35.000 --> 0:20:40.080 of your nervous system is being invaded by this virus. So, 0:20:40.280 --> 0:20:44.320 in the case of West Nile meningitis, the symptoms look 0:20:44.359 --> 0:20:48.679 like meningitis, which is a sudden onset of fever, a 0:20:49.040 --> 0:20:55.800 very very massive headache, stiff neck, photophobia which is difficulty 0:20:55.800 --> 0:20:58.080 looking at light and it becomes very painful to look 0:20:58.080 --> 0:21:03.439 at light. If it progresses to encephalitis, then you often 0:21:03.480 --> 0:21:08.000 have those same meningial symptoms, but then you also will 0:21:08.040 --> 0:21:11.000 have things like altered level of consciousness, which means you 0:21:11.000 --> 0:21:15.880 can slip into a coma essentially, or just personality changes 0:21:15.960 --> 0:21:19.200 because of swelling and inflammation in different areas of your 0:21:19.240 --> 0:21:23.960 actual brain. And West Nile encephalitis tends to be the 0:21:24.000 --> 0:21:26.000 most severe with the worst outcomes. 0:21:26.880 --> 0:21:29.800 Okay, and so this might be a very basic question, 0:21:31.160 --> 0:21:35.040 But does it always progress meningitis and then encephalitis. 0:21:35.160 --> 0:21:37.639 No, not necessarily, and we'll get to that in just 0:21:37.680 --> 0:21:42.760 a minute kind of maybe, well, let me just keep going. 0:21:43.400 --> 0:21:47.200 So West Nile virus also then can cause acute flaccid 0:21:47.240 --> 0:21:52.360 paralysis aarin. Do you remember what other disease we've covered 0:21:52.760 --> 0:21:55.679 that does the exact same thing. Oh you remembered so quickly. 0:21:56.240 --> 0:21:59.119 Well, okay, but I have to confess I've watched like 0:21:59.160 --> 0:22:04.119 a bunch of YouTube on West Nile virus, and there 0:22:04.320 --> 0:22:07.480 was one where like a physician came on and talked 0:22:07.520 --> 0:22:10.480 about it, yeah, and was like, I haven't seen a 0:22:10.480 --> 0:22:14.480 polio case, but this is apparently exactly like polio. 0:22:14.680 --> 0:22:18.720 Yeah, they actually call it poliomyelitis, even though it's caused 0:22:18.720 --> 0:22:21.679 by a completely different virus, which I think confuses me. 0:22:21.840 --> 0:22:25.760 It confused me too. It was like, but wait, yeah, 0:22:26.320 --> 0:22:29.040 but basically what can happen is that if West Nile 0:22:29.119 --> 0:22:34.399 virus specifically infects the anterior horn cells of the spinal cord. 0:22:34.880 --> 0:22:37.040 This is the part of our spinal cord where our 0:22:37.080 --> 0:22:41.840 motor neurons exit the spinal cord, that is the exact 0:22:41.920 --> 0:22:47.280 same area that poliovirus infects and causes swelling and then damage. 0:22:47.400 --> 0:22:51.800 And so this looks just like polio did. Your muscles 0:22:51.800 --> 0:22:54.560 and your limbs go weak. In the case of West 0:22:54.600 --> 0:22:58.280 Nile virus, it's often asymmetric, so it can look a 0:22:58.280 --> 0:22:59.200 lot like a stroke. 0:22:59.800 --> 0:23:00.440 Interesting. 0:23:00.920 --> 0:23:04.000 It is interesting. Why is it asymmetric. I don't know, 0:23:04.200 --> 0:23:06.920 and it's not always. It's just that oftentimes it can 0:23:07.040 --> 0:23:10.399 be okay. Presumably it's just that this is where the 0:23:10.480 --> 0:23:11.320 virus ended up. 0:23:12.320 --> 0:23:15.359 So if somebody goes to the hospital and presents with 0:23:15.560 --> 0:23:20.240 acute flaccid paralysis, are there other things like or is 0:23:20.280 --> 0:23:22.080 West Nile sort of top of the list? I mean, 0:23:22.119 --> 0:23:25.760 depending of course on geography, their history, et cetera. 0:23:25.920 --> 0:23:29.160 Depending It would depend on all those things. And West 0:23:29.240 --> 0:23:32.359 Nile virus. Of course, polio can also cause it, but 0:23:32.400 --> 0:23:35.879 that's generally not around most of the world these days. 0:23:36.760 --> 0:23:39.520 I don't know if there are other viruses. I imagine 0:23:39.520 --> 0:23:41.679 there are a handful of other viruses that can do that. 0:23:42.520 --> 0:23:46.440 One way that might differentiate this from stroke could be 0:23:46.680 --> 0:23:49.239 a range, especially if it's someone who has no other 0:23:49.320 --> 0:23:53.320 risk factors coming in. Importantly, West Nile virus tends to 0:23:53.480 --> 0:23:58.960 not affect your cranial nerves, and strokes often do so 0:23:59.200 --> 0:24:01.560 if you think of they have like those you know, 0:24:01.600 --> 0:24:05.440 public information campaigns about looking for a drooping face. That's 0:24:05.920 --> 0:24:08.720 when your cranial nerves are affected, which tends to not 0:24:08.800 --> 0:24:12.200 be affected with West Nile. In fact, in many cases 0:24:12.400 --> 0:24:17.680 West Nile acute flacid paralysis can mimic gion Beret disease. Huh, 0:24:17.800 --> 0:24:21.639 but gion Beret usually has sensory symptoms as well, and 0:24:21.680 --> 0:24:26.320 West Nile tends to not, although it can huh. Okay, 0:24:26.560 --> 0:24:31.000 I know it's complicated. It's complicated. And with any of 0:24:31.080 --> 0:24:35.880 these neuroinvasive versions of West Nile virus, you may also 0:24:36.040 --> 0:24:39.920 have some other signs things like nausea, vomiting, you might 0:24:40.000 --> 0:24:43.400 have a rash, you might have vision changes. So it's 0:24:43.440 --> 0:24:46.400 the constellation of all these symptoms. It tends to not 0:24:46.520 --> 0:24:52.879 just be one symptom isolated. And some people have like 0:24:52.920 --> 0:24:56.840 a viral prodrome, so some kind of mild viral type 0:24:56.880 --> 0:25:01.479 symptoms fever, chills, feeling cruddy, pride to the onset of 0:25:01.520 --> 0:25:05.760 these invasive symptoms. Others don't or at least don't remember 0:25:06.119 --> 0:25:12.000 having one. So the good news is that for most 0:25:12.080 --> 0:25:17.639 cases of West Nile virus, even the neuroinvasive cases, people 0:25:17.760 --> 0:25:22.800 tend to make a full recovery. However, the worst outcomes 0:25:22.800 --> 0:25:26.119 do tend to be in people who progress to encephalitis. 0:25:26.920 --> 0:25:30.120 And when we look at all of the neuroinvasive disease 0:25:30.480 --> 0:25:36.399 lumped together, so this is meningitis encephalitis AFP, but really 0:25:36.520 --> 0:25:40.600 the fatality tends to come from encephalitis or meningitis. In 0:25:40.640 --> 0:25:44.399 those neuroinvasive disease cases, the case fatality rate can be 0:25:44.440 --> 0:25:48.199 as high as ten percent overall, or even higher for 0:25:48.280 --> 0:25:53.399 those that are older than seventy and for many, many people, 0:25:53.520 --> 0:25:57.080 especially with this neurologic symptoms, the recovery process can be 0:25:57.320 --> 0:25:59.960 very very slow, taking up to a year or more. 0:26:00.480 --> 0:26:04.480 And in some cases, especially with this acute flacid paralysis 0:26:04.840 --> 0:26:08.440 or in some cases with encephalitis, people may lose function 0:26:08.560 --> 0:26:12.560 that they never are able to regain because nerves are damaged. 0:26:12.600 --> 0:26:15.520 Things are damage that just are not able to recover, and. 0:26:15.840 --> 0:26:19.840 The damage is caused by just inflammation by the viruses, 0:26:20.280 --> 0:26:21.000 you know, being there. 0:26:21.160 --> 0:26:24.199 Yeah, So that's the question, right, right, right, that's the 0:26:24.600 --> 0:26:27.280 what is the what is the path of physiology of 0:26:27.320 --> 0:26:29.800 this disease? I haven't even I haven't even started to 0:26:29.800 --> 0:26:35.359 talk about it. So here let's try, shall we. Let's 0:26:35.400 --> 0:26:39.280 do it? Okay, So, being a virus, we all know 0:26:39.400 --> 0:26:42.679 by now that viruses have to invade our cells in 0:26:42.800 --> 0:26:48.840 order to cause disease. It's thought that initially, primarily when 0:26:48.840 --> 0:26:51.360 we get infected, one of the major cells that West 0:26:51.400 --> 0:26:55.400 Nile virus tends to infect are our dendritic cells, which 0:26:55.400 --> 0:26:58.560 are one of our immune cells that usually help to 0:26:58.800 --> 0:27:02.159 present antigens to our immune system like a flag so 0:27:02.200 --> 0:27:05.040 that we can make antibodies. So it's a pretty good 0:27:05.080 --> 0:27:08.760 cell for a virus to hide within, and westnilvirus, like 0:27:08.920 --> 0:27:13.600 many other flavaviruses, is very good at suppressing our overall 0:27:13.640 --> 0:27:19.000 immune response to infection. So as it invades these dendritic cells, 0:27:19.240 --> 0:27:22.320 those cells travel to our lymph nodes because that's where 0:27:22.320 --> 0:27:26.880 they like to go to present their antigens. But westnilvirus 0:27:27.000 --> 0:27:29.880 is then able to escape from those dendritic cells from 0:27:29.920 --> 0:27:33.080 our lymph nodes, enter our blood stream and travel wherever 0:27:33.160 --> 0:27:37.159 it wants. And as we've just gone over, one of 0:27:37.160 --> 0:27:39.560 the big hallmarks of west nile virus is that it 0:27:39.720 --> 0:27:43.120 somehow can make it from our blood stream into our 0:27:43.160 --> 0:27:46.600 central nervous system, our spinal cord, our Meningji's or our 0:27:46.680 --> 0:27:51.879 actual brain. So how is it actually able to do this? Like, 0:27:52.200 --> 0:27:55.240 how can it be so neuroinvasive? We're supposed to have 0:27:55.280 --> 0:27:58.000 a blood brain barrier that's supposed to literally stop this, 0:27:59.359 --> 0:28:02.760 and the answer is that we don't know exactly how 0:28:02.760 --> 0:28:05.480 it's able to do this. How is it so good 0:28:05.560 --> 0:28:08.160 at evating our immune response and making its way into 0:28:08.160 --> 0:28:14.000 our central nervous system. There are four at least different hypotheses. 0:28:15.200 --> 0:28:20.000 One is that it just releases or causes us to 0:28:20.119 --> 0:28:23.640 release a lot of cytokines. Probably a lot of people 0:28:23.680 --> 0:28:26.560 have heard of cytokines by now because of COVID and 0:28:26.640 --> 0:28:30.199 our influenza episode way back when. But these basically just 0:28:30.560 --> 0:28:34.679 increase the permeability of our vascular membranes, allowing more things 0:28:34.720 --> 0:28:37.719 to pass through. It's so that inflammation can get in 0:28:37.760 --> 0:28:40.520 there to do its job, but it also allows for 0:28:40.640 --> 0:28:44.240 viruses to make it across that blood brain barrier. That's 0:28:44.280 --> 0:28:48.760 one hypothesis. The second is that it actually just can 0:28:48.840 --> 0:28:52.640 warm its way by entering through our endothelial cells, those 0:28:52.680 --> 0:28:55.320 cells that line the blood brain barrier. It can invade 0:28:55.360 --> 0:29:00.960 those cells and then make it through. Another possible hypothesis 0:29:01.240 --> 0:29:07.120 is that it invades via macrophages. Ah right, So macrophages 0:29:07.160 --> 0:29:10.560 are another one of our white blood cells that sometimes 0:29:10.640 --> 0:29:14.280 move across the blood brain barrier for our protection. But 0:29:14.400 --> 0:29:19.600 this virus can potentially be harbored within those macrophases. And finally, 0:29:19.720 --> 0:29:24.680 my favorite hypothesis is maybe it does a little bit 0:29:24.680 --> 0:29:28.840 of rabies and it actually travels on our neurons and 0:29:28.880 --> 0:29:33.200 does retrograde axonal transport all the way to our central 0:29:33.200 --> 0:29:33.880 nervous system. 0:29:34.680 --> 0:29:36.960 Ah, that is scary. 0:29:37.320 --> 0:29:40.840 Yeah, and we don't know, We don't know which of 0:29:40.880 --> 0:29:46.240 those tends to be the biggest driver and why. Huh. Yeah, 0:29:46.360 --> 0:29:50.920 it's especially interesting because again, neuroinvasive disease can be very serious, 0:29:50.920 --> 0:29:54.480 but it's very rare in West Nile, and yet it's 0:29:54.520 --> 0:29:58.240 also one of the most common causes of viral certainly 0:29:58.240 --> 0:30:04.520 of vector borne viral and stephal in North America. Right. Interesting, 0:30:04.680 --> 0:30:07.320 it's very interesting. So I don't have a good answer 0:30:07.320 --> 0:30:09.080 for you erin in terms of how much of this 0:30:09.160 --> 0:30:13.440 damage is caused by viral damage directly versus our immune 0:30:13.440 --> 0:30:17.600 response and inflammation therein, because we don't even fully understand 0:30:17.680 --> 0:30:20.920 how this virus even makes it into our central nervous 0:30:20.920 --> 0:30:21.800 system to begin with. 0:30:22.720 --> 0:30:27.000 So there are other flavvy viruses that invade the central 0:30:27.000 --> 0:30:32.440 nervous system, certainly, And do we know the mechanisms for this, 0:30:34.640 --> 0:30:35.200 I don't. 0:30:36.880 --> 0:30:43.080 I don't, But I imagine that these hypotheses that have been proposed, 0:30:43.360 --> 0:30:47.320 which I didn't come up with have been proposed based 0:30:47.360 --> 0:30:50.600 on both mouse models of West Nile virus infection as 0:30:50.640 --> 0:30:54.160 well as other similar flavaviruses like Japanese encephalitis, etc. 0:30:54.760 --> 0:30:55.440 That makes sense. 0:30:56.000 --> 0:31:04.440 Yeah, so that's kind of the overall biology. It is, 0:31:06.040 --> 0:31:09.800 I will say, relatively easy to diagnose, but also of 0:31:09.840 --> 0:31:14.440 course difficult to diagnose in other ways. Mainly, we tend 0:31:14.440 --> 0:31:18.520 to diagnose by looking for antibodies to the virus, which 0:31:19.080 --> 0:31:22.440 tend to be apparent after about eight days after the 0:31:22.480 --> 0:31:26.160 onset of symptoms. Most of the time you can find 0:31:26.200 --> 0:31:28.400 them after that amount of time, but you have to 0:31:28.400 --> 0:31:31.080 be able to test like between eight and twenty one 0:31:31.160 --> 0:31:33.920 days after symptoms start for that test to be accurate. 0:31:34.840 --> 0:31:38.160 You can test for the virus itself, but then those 0:31:38.200 --> 0:31:40.320 tests are sometimes hard to come by depending on where 0:31:40.360 --> 0:31:41.120 you live, etc. 0:31:42.080 --> 0:31:46.480 I've also read that it's not easily detectable because humans 0:31:46.520 --> 0:31:49.280 tend to like circulate less virus in. 0:31:49.280 --> 0:31:52.360 Their bloods right very low levels of virus. And then 0:31:52.400 --> 0:31:54.680 it also depends on are you testing blood or are 0:31:54.680 --> 0:31:58.760 you testing cerebrospinal fluid for meningitis or is it just 0:31:58.800 --> 0:32:02.920 for like a general and felt in general. At least 0:32:02.960 --> 0:32:04.760 as far as I could tell we don't have any 0:32:05.000 --> 0:32:08.320 specific antiviral treatment for West Nile virus, so treatment is 0:32:08.440 --> 0:32:11.840 just supportive, the way that you would treat anybody with 0:32:12.040 --> 0:32:15.440 a meningitis or an encephalitis that's not bacterial, So just 0:32:15.480 --> 0:32:19.480 sort of supportive care. And that is the biology of 0:32:19.520 --> 0:32:23.160 West Nile. Aaron, I know you have a lot to 0:32:23.160 --> 0:32:27.120 tell me about where this sole virus came from. I 0:32:27.160 --> 0:32:29.800 do Okay, good shall. 0:32:29.560 --> 0:32:32.120 We Yeah, I'll dive in as soon as we take 0:32:32.200 --> 0:33:09.000 a quick break. Well, actually, Aaron, this history section is 0:33:09.280 --> 0:33:12.560 gonna be kind of like a total break from the 0:33:12.640 --> 0:33:14.280 last few episodes we've done. 0:33:14.840 --> 0:33:16.160 Okay in what way? 0:33:16.440 --> 0:33:22.680 Well, okay, diabetes absolutely enormous history, Anthrax. 0:33:22.320 --> 0:33:24.320 Huge, oh my gosh, so big. 0:33:24.560 --> 0:33:29.080 Yeah, Shaga disease, super extensive history, all of it. But 0:33:29.440 --> 0:33:32.640 the history of West Nile, although it does date back, 0:33:32.840 --> 0:33:36.960 you know, probably further than you might think, it's fairly 0:33:37.000 --> 0:33:41.440 what I would say, that's straightforward, okay, Which isn't to 0:33:41.560 --> 0:33:44.520 say like, that's not to say that it's uninteresting or 0:33:44.520 --> 0:33:47.520 that it can't tell us anything about big picture science 0:33:48.000 --> 0:33:51.560 or big picture society or big picture public health issues, 0:33:51.600 --> 0:33:53.000 because it definitely can. 0:33:53.480 --> 0:33:54.840 Oh, I have no doubt Aaron. 0:33:55.760 --> 0:33:58.280 But before we get to that, we have to start 0:33:58.360 --> 0:34:01.960 back a bit of course. Where did this virus come from? 0:34:02.280 --> 0:34:04.360 And how did we get to where we are today 0:34:04.400 --> 0:34:04.720 with it? 0:34:05.360 --> 0:34:07.960 And what did they say in the ebers pavirus Well, 0:34:08.480 --> 0:34:11.120 sadly or not sadly, I don't know. 0:34:11.280 --> 0:34:14.520 It doesn't seem to be mentioned, at least that I 0:34:14.560 --> 0:34:20.120 could gather try So, like you mentioned, Aaron, West Nile 0:34:20.200 --> 0:34:22.960 virus is a flavvy virus, and it's related to other 0:34:22.960 --> 0:34:26.200 flavvy viruses, like you know, the ones you named yellow 0:34:26.200 --> 0:34:29.200 fever virus, which I honestly it's been so long that 0:34:29.239 --> 0:34:32.280 I don't remember if I covered this in that episode. 0:34:32.320 --> 0:34:35.680 But the name flavvy virus actually comes from the Latin 0:34:35.760 --> 0:34:40.200 word flavus for yellow, which I also think then kind 0:34:40.239 --> 0:34:44.920 of adds a fun little layer to the base to 0:34:44.960 --> 0:34:46.160 the recipe for our drink. 0:34:46.239 --> 0:34:49.920 Yeah, yeah, I agree. Also, I can't remember if you 0:34:50.000 --> 0:34:52.040 said that in Yellow Fever either, so I'm glad that 0:34:52.080 --> 0:34:52.880 you told us again. 0:34:53.000 --> 0:34:58.560 Yeah, but yeah, danky virus, seek a virus, Japanese encephalitis virus, 0:34:58.600 --> 0:35:02.000 Saint Louis and cephalitis virus, take born encephalitis virus, and. 0:35:01.920 --> 0:35:06.080 So on, so many so many, many, and. 0:35:06.200 --> 0:35:09.759 Of all of these flavvy viruses, West Nile virus is 0:35:09.800 --> 0:35:13.560 one of the earliest described and one of the most 0:35:13.719 --> 0:35:14.839 widely distributed. 0:35:15.560 --> 0:35:20.200 Huh, yeah, I know, it was a little surprising. Yeah, 0:35:20.280 --> 0:35:23.000 I knew it was widely distributed. I didn't know it 0:35:23.040 --> 0:35:25.320 was one of the earliest ones get. 0:35:24.880 --> 0:35:26.640 Into Oh I am. 0:35:27.800 --> 0:35:31.000 So we can use things like zerological studies and genomic 0:35:31.040 --> 0:35:33.560 analyses to tell us how it came to have what 0:35:33.719 --> 0:35:37.480 is basically this global distribution, and what it looks like 0:35:37.680 --> 0:35:41.000 is that West Nile virus evolved in Africa. I don't 0:35:41.040 --> 0:35:44.160 have an exact or even a rough date estimate for that, 0:35:44.320 --> 0:35:47.960 or an exact location or even a rough location, but 0:35:48.000 --> 0:35:51.799 that's where serological studies show that the virus is circulating 0:35:51.840 --> 0:35:55.640 continuously and has been that way for quite some time. 0:35:56.600 --> 0:35:59.719 And this year round transmission is in contrast with the 0:35:59.719 --> 0:36:03.399 past veterans in other places such as Europe, where West 0:36:03.480 --> 0:36:08.239 Nile virus was introduced from Africa via migratory birds and 0:36:08.280 --> 0:36:11.040 where it tends to pop up in this more seasonal 0:36:11.200 --> 0:36:14.880 transient form. And West Nile virus was brought to India 0:36:15.000 --> 0:36:18.960 via trade, probably around like the early eighteen hundreds, eighteen 0:36:19.000 --> 0:36:22.640 twenties or so when there was extensive trade between Africa 0:36:22.680 --> 0:36:27.040 and India, and then to like Australia or the Australasia 0:36:27.080 --> 0:36:31.520 region in the mid eighteen hundreds. And this last one, 0:36:31.800 --> 0:36:35.279 like how it got to Australia is a bit of 0:36:35.320 --> 0:36:40.920 a mystery because there are apparently no bird migrations that 0:36:41.080 --> 0:36:48.000 connect Australia and Africa. Although any bird friends nick, yeah, 0:36:48.040 --> 0:36:51.799 Fred Cole, Maria Nate nick, we. 0:36:51.800 --> 0:36:52.799 Have a lot of bird friends. 0:36:52.840 --> 0:36:55.480 Do have a lot of bird friends, way in if 0:36:55.520 --> 0:37:01.520 you know something else, but yeah, so it because of that, 0:37:01.600 --> 0:37:05.200 it's been suggested that West nolevirus was actually introduced to 0:37:05.360 --> 0:37:08.640 Australia from Africa in a similar way that yellow fever 0:37:08.760 --> 0:37:13.239 virus was brought to North America from infected mosquitoes on 0:37:13.360 --> 0:37:18.520 ships carrying enslaved people as Europeans traveled to Australia from Africa. 0:37:19.280 --> 0:37:22.200 Oh okay, And it seems that really the only place 0:37:22.239 --> 0:37:25.720 where Westnile virus is not present besides like the Arctic 0:37:25.760 --> 0:37:30.320 and Antarctica, is in a lot of parts of Eastern Asia, 0:37:31.000 --> 0:37:34.280 and the reasons for that are not quite clear. Maybe 0:37:34.280 --> 0:37:37.719 it's like a competition thing with other encephalitis viruses, I 0:37:37.800 --> 0:37:42.200 don't know. A mosquito incompatibility, hosting compatibility. 0:37:41.480 --> 0:37:41.880 I don't know. 0:37:42.520 --> 0:37:44.120 And I'm not going to get too much into the 0:37:44.160 --> 0:37:47.319 details of like the different lineages and the clades that 0:37:47.400 --> 0:37:50.440 the virus can be broken down into, because there's a lot, 0:37:51.280 --> 0:37:54.279 but just to say that they do exist and that 0:37:54.320 --> 0:37:57.239 they can help us in new outbreaks to see where 0:37:57.280 --> 0:38:01.000 the virus is coming from and identify ways that it 0:38:01.080 --> 0:38:04.960 got there. For instance, like was it a single introduction 0:38:05.080 --> 0:38:08.960 event or multiple It's thought that West Nile virus was 0:38:09.040 --> 0:38:14.040 introduced to Europe and North America in several independent introduction events, 0:38:14.480 --> 0:38:17.640 while it was brought to Australia in just one. And 0:38:17.640 --> 0:38:20.520 then how much has the virus evolved since arriving in 0:38:20.560 --> 0:38:23.840 a new area? Are there path of physiological differences among 0:38:23.880 --> 0:38:28.120 the different clades that could have clinical implications or ecological 0:38:28.120 --> 0:38:30.920 differences that could change the way we control it, et cetera. 0:38:31.280 --> 0:38:34.399 So it's a useful area. It's just like a lot 0:38:34.440 --> 0:38:38.719 of minute detail that sort of open ended questions in 0:38:38.760 --> 0:38:39.520 some ways. 0:38:39.880 --> 0:38:40.160 Yeah. 0:38:40.360 --> 0:38:43.920 Yeah, So I mentioned that West Nile virus was one 0:38:43.960 --> 0:38:47.799 of the earliest described flappy viruses, but the way that 0:38:47.840 --> 0:38:50.360 it happened was kind of a fluke. 0:38:50.880 --> 0:38:51.959 Oh yeah, oh yeah. 0:38:52.640 --> 0:38:56.400 In nineteen thirty seven, researchers were conducting a wide scale 0:38:56.440 --> 0:39:00.920 epidemiological study on yellow fever in Uganda and a person 0:39:01.040 --> 0:39:04.040 from the West Nile District of Northern Uganda was brought 0:39:04.080 --> 0:39:07.640 into the study presenting with a fever. But when they 0:39:07.680 --> 0:39:12.720 tested this person's serum against yellow fever virus, it didn't match. Instead, 0:39:12.719 --> 0:39:15.400 it looked to be more similar to other flabby viruses 0:39:15.440 --> 0:39:20.400 that caused encephalitis, Saint Louis encephalitis and Japanese b encephalitis viruses, 0:39:21.080 --> 0:39:24.040 and even though the person only had a fever, they 0:39:24.120 --> 0:39:29.360 noted that it seemed to have neurotropic tendencies. The researchers 0:39:29.400 --> 0:39:32.440 described this new virus in a paper in nineteen forty, 0:39:32.880 --> 0:39:37.520 which is like older than I expected for we style virus. 0:39:38.200 --> 0:39:38.960 It really is. 0:39:39.800 --> 0:39:43.440 Yeah. Also, I just have to complain here for a 0:39:43.480 --> 0:39:48.320 second because that paper published in nineteen forty is eighty 0:39:48.320 --> 0:39:51.520 one years ago. Yeah, is still behind a paywall? 0:39:51.960 --> 0:39:52.960 Are you serious? 0:39:53.200 --> 0:39:54.240 I am serious. 0:39:54.520 --> 0:39:55.560 That's ridiculous. 0:39:55.760 --> 0:39:58.880 Yeah, I mean, like, can we just make everything open access? 0:39:59.000 --> 0:40:00.479 It would make the world of place. 0:40:00.719 --> 0:40:04.200 Okay, eighty one years old, I know, I know. 0:40:04.680 --> 0:40:09.640 Wow, frustrating anyway, So why did I call the discovery 0:40:09.640 --> 0:40:12.960 of West Nile virus a fluke? Well, for one, it 0:40:13.040 --> 0:40:16.239 was discovered kind of accidentally, like those researchers weren't out 0:40:16.280 --> 0:40:19.720 looking for the cause of an outbreak of unexplained febrile illness. 0:40:20.640 --> 0:40:23.080 And for two over the next sixty years or so 0:40:23.160 --> 0:40:29.319 after its discovery, westnyle virus was not really considered that much, like, 0:40:29.360 --> 0:40:32.960 it didn't rank that highly on the list of pathogens 0:40:33.000 --> 0:40:35.759 of public health importance. Yeah, now, there were a lot 0:40:35.800 --> 0:40:37.759 of other and there still are a lot of other 0:40:37.800 --> 0:40:41.040 mosquito born viruses that cause a lot more widespread morbidity 0:40:41.040 --> 0:40:43.880 and mortality, and so West Nile virus was kind of 0:40:43.960 --> 0:40:47.919 just like, oh, that's just another one of those flappy viruses, right. 0:40:48.600 --> 0:40:51.040 And the third reason is that you know, like we 0:40:51.080 --> 0:40:54.239 talked about in the biology, the virus isn't often easily 0:40:54.360 --> 0:40:59.000 isolated and infected humans like in blood. So the fact 0:40:59.040 --> 0:41:00.759 that they were able to ice related at all, I 0:41:00.760 --> 0:41:05.080 think is kind of interesting. So it wasn't until the 0:41:05.160 --> 0:41:08.640 nineteen fifties that the first outbreaks of West Nile virus 0:41:08.640 --> 0:41:12.160 were observed, like the first time that people recognized that 0:41:12.320 --> 0:41:16.760 West Nile virus could be capable of causing widespread outbreak. 0:41:16.360 --> 0:41:19.480 Like an outbreak, not just like an incidental disease here 0:41:19.520 --> 0:41:20.880 and there exactly. 0:41:21.880 --> 0:41:25.520 And that started with the first recognized epidemic in Israel 0:41:25.680 --> 0:41:29.600 in nineteen fifty one, one hundred and twenty three cases 0:41:29.600 --> 0:41:34.960 occurred in a small town the size of three hundred 0:41:35.000 --> 0:41:36.040 and three people. 0:41:36.520 --> 0:41:39.000 I'm sorry, you said, one hundred and sixty cases in 0:41:39.000 --> 0:41:40.560 a one hundred and three hundred. 0:41:40.239 --> 0:41:43.160 One hundred and twenty three out of three hundred people here. 0:41:43.160 --> 0:41:46.640 Oh my goodness, I know that's a pretty high attack rate, 0:41:47.080 --> 0:41:48.360 really really high. 0:41:49.320 --> 0:41:53.360 No fatalities occurred, and in fact, most of the people 0:41:53.400 --> 0:41:57.680 affected were children. But this was the first time, really 0:41:57.719 --> 0:42:00.520 that the various disease symptoms that this virus can cause 0:42:00.560 --> 0:42:04.320 were recognized, things like you already mentioned, you know, fever, headache, 0:42:04.320 --> 0:42:08.239 abdominal pain, vomiting, etc. And around the same time as 0:42:08.280 --> 0:42:12.000 this epidemic in Israel or not long after, a series 0:42:12.040 --> 0:42:15.040 of outbreaks of West Nile virus popped up in Egypt. 0:42:15.440 --> 0:42:18.920 And during these outbreaks a lot more ground was covered 0:42:18.960 --> 0:42:23.400 in terms of understanding the disease ecology, clinical characteristics, and 0:42:23.480 --> 0:42:28.279 epidemiological patterns for instance, this is when researchers realized that 0:42:28.400 --> 0:42:32.320 a large proportion of people infected never showed any symptoms, 0:42:33.120 --> 0:42:36.840 that children in these areas tended to have more symptomatic illness, 0:42:37.320 --> 0:42:40.480 but adolescents and adults tended to have higher zero prevalence, 0:42:40.880 --> 0:42:43.960 so suggesting that like in these places where the virus 0:42:44.000 --> 0:42:48.280 was endemic and like continuously circulating, people were likely exposed 0:42:48.280 --> 0:42:49.560 to the virus at a young age. 0:42:49.880 --> 0:42:52.879 Interesting. Interesting, interesting Yeah. 0:42:52.920 --> 0:42:56.000 And researchers also in these early outbreaks in the nineteen 0:42:56.040 --> 0:43:00.680 fifties found the virus in many species of birds and 0:43:00.760 --> 0:43:03.799 also in some species of mammals, and this is when 0:43:03.840 --> 0:43:06.560 they made the link between mosquitos. 0:43:06.320 --> 0:43:07.040 And the virus. 0:43:07.360 --> 0:43:09.879 Okay, cool, wow, a lot oh yeah, a. 0:43:09.800 --> 0:43:10.400 Lot of ground. 0:43:10.640 --> 0:43:11.520 Yeah. 0:43:11.600 --> 0:43:15.839 And finally, some of the neurological complications of infection were 0:43:15.840 --> 0:43:19.960 observed during these early outbreaks in Israel and Egypt, things 0:43:20.000 --> 0:43:24.680 like these rare instances of meningitis or encephalitis. But overall, 0:43:24.719 --> 0:43:28.440 these outbreaks really kind of served to reinforce the idea 0:43:28.560 --> 0:43:32.680 in many ways that West Nile virus was mostly asymptomatic 0:43:33.080 --> 0:43:37.400 or if anything, generally like a mild mosquito born illness. 0:43:38.320 --> 0:43:42.160 And this prevailing perception can be seen in the experimental 0:43:42.200 --> 0:43:46.120 infection studies that took place in Egypt during this time, 0:43:46.800 --> 0:43:50.440 where people with terminal cancer were intentionally infected with the 0:43:50.520 --> 0:43:53.720 virus to see if the resulting fever would help suppress 0:43:53.760 --> 0:43:54.760 the cancer's growth. 0:43:55.160 --> 0:43:57.560 Oh gosh, well, this was actually. 0:43:57.239 --> 0:44:01.120 Apparently like a fairly common or at least occasional type 0:44:01.120 --> 0:44:05.640 of experimental treatment during this time that people were like 0:44:05.800 --> 0:44:08.320 exploring or looking into interesting. 0:44:08.880 --> 0:44:09.680 Was it effective? 0:44:11.200 --> 0:44:11.279 So? 0:44:12.200 --> 0:44:15.319 I don't know, because again I don't have access to 0:44:15.440 --> 0:44:16.840 this old paper either. 0:44:16.960 --> 0:44:20.680 From grade nineteen fifties, which is kind of annoying, which 0:44:20.719 --> 0:44:23.520 also means that I couldn't read between the lines to 0:44:23.600 --> 0:44:27.440 see whether this falls under you know, actual experiment or 0:44:27.520 --> 0:44:28.520 medicalized torture. 0:44:28.920 --> 0:44:33.960 You know, does volunteer have quotes around it? Yeah, et cetera. Ok, Yeah, 0:44:34.000 --> 0:44:37.400 but these studies were terminated when several of the people 0:44:37.400 --> 0:44:40.360 who were infected developed encephalitis. 0:44:40.360 --> 0:44:42.960 Makes sense, Yeah, reasonable stopping point. 0:44:44.560 --> 0:44:48.319 But during these studies, the researchers also did make some 0:44:48.440 --> 0:44:52.440 important observations in terms of things like viremia, like how 0:44:52.520 --> 0:44:55.719 much virus was circulating and when and how long it 0:44:55.719 --> 0:44:58.560 could be detected, and how the amount of virus circulating 0:44:58.600 --> 0:45:00.560 correlated with the severity disease. 0:45:01.320 --> 0:45:04.120 Okay, So following. 0:45:03.640 --> 0:45:07.400 These outbreaks in Egypt and Israel, West Nile virus continued 0:45:07.400 --> 0:45:11.640 to make sporadic appearances across parts of Africa, the Mediterranean 0:45:11.880 --> 0:45:15.920 and Europe, popping up in France, South Africa, Russia, Spain, 0:45:16.040 --> 0:45:19.000 and India and some other places. And in the course 0:45:19.040 --> 0:45:22.760 of these epidemics, it became more apparent that this virus 0:45:22.840 --> 0:45:27.799 can absolutely cause neurological disease in some people, which might 0:45:27.880 --> 0:45:31.279 have brought it more research attention at the time. So 0:45:31.320 --> 0:45:34.319 like in the fifties and sixties, if not for the 0:45:34.360 --> 0:45:38.719 fact that large outbreaks of the virus all but stopped 0:45:39.000 --> 0:45:42.520 throughout the nineteen seventies and nineteen eighties, like they just 0:45:43.160 --> 0:45:45.960 I don't know whether it was just like observation plummeted, 0:45:46.120 --> 0:45:49.680 or the ecology made it to just like really put 0:45:49.719 --> 0:45:50.920 it in a lull period. 0:45:51.560 --> 0:45:52.000 I don't know. 0:45:54.040 --> 0:45:57.520 But in nineteen ninety six, a new era of West 0:45:57.600 --> 0:46:02.680 Nile virus began, first with a large epidemic in southern Romania. 0:46:03.920 --> 0:46:05.960 And not only was this one of the. 0:46:05.920 --> 0:46:09.320 Biggest recognized outbreaks of West Nile virus, with at least 0:46:09.320 --> 0:46:13.160 three hundred and ninety three hospitalizations and seventeen deaths, and 0:46:13.280 --> 0:46:17.719 who knows how many actual infections, But it also involved 0:46:17.800 --> 0:46:20.720 a lot of neurological cases, and it was the first 0:46:20.719 --> 0:46:24.000 to happen in what was basically a mostly urban area, 0:46:24.960 --> 0:46:29.319 whereas previous outbreaks had been more rural. And over the 0:46:29.320 --> 0:46:32.239 next couple of years it became clear that this wasn't like, 0:46:32.400 --> 0:46:35.440 this wasn't a one off. West Nile virus seemed to 0:46:35.440 --> 0:46:40.200 be undergoing a change in its epidemiology After the epidemic 0:46:40.239 --> 0:46:43.360 in Romania. The virus popped up in Morocco in nineteen 0:46:43.440 --> 0:46:46.920 ninety six, in Tunisia in nineteen ninety seven, in Italy 0:46:47.040 --> 0:46:49.520 and Israel in nineteen ninety eight, and in Russia in 0:46:49.640 --> 0:46:53.920 nineteen ninety nine, and like the nineteen ninety six Romanian outbreak, 0:46:53.960 --> 0:46:56.960 these were also in urban areas, seemed to have higher 0:46:57.040 --> 0:47:01.239 rates of neurological involvement with a higher fatality, and had 0:47:01.239 --> 0:47:05.759 a tendency to impact mostly people in older age groups. 0:47:06.560 --> 0:47:09.640 So by the time August nineteen ninety nine rolled around, 0:47:10.080 --> 0:47:13.600 the pattern had already been set. But West Nyle virus 0:47:13.640 --> 0:47:18.160 still held one more big surprise for everyone, and that 0:47:18.520 --> 0:47:21.280 was that it had made the leap across the ocean 0:47:21.360 --> 0:47:23.000 and into North America. 0:47:23.760 --> 0:47:26.880 Ooh, big splash, big splash. 0:47:27.360 --> 0:47:30.200 So far West style virus I think has taught us 0:47:30.320 --> 0:47:33.000 a couple of really important lessons, or at least like 0:47:33.160 --> 0:47:38.040 reemphasize them. And since Aaron, you're like, we've talked about 0:47:38.040 --> 0:47:41.200 this many times and listeners, if you've tuned in before, 0:47:41.440 --> 0:47:43.839 these are going to sound familiar, but I'm gonna say 0:47:43.880 --> 0:47:48.560 them anyway. The first is to not underestimate a virus. 0:47:49.360 --> 0:47:51.560 Never underestimate a virus. 0:47:52.000 --> 0:47:56.160 Yeah, many viruses that appeared mild at first can go 0:47:56.280 --> 0:48:00.200 on to have serious complications or long term effects. Not all, 0:48:00.280 --> 0:48:03.560 of course, but the potential is there. Like remember chicken. 0:48:03.320 --> 0:48:04.320 Pox for instance. 0:48:04.560 --> 0:48:05.120 Remember it. 0:48:06.600 --> 0:48:09.479 And the second lesson is that human movement and human 0:48:09.520 --> 0:48:13.160 modification of the environment can alter the dynamics of infection 0:48:13.680 --> 0:48:17.840 in a very major way. Yeah, this isn't new stuff, 0:48:18.040 --> 0:48:23.200 but it's definitely important stuff. And so these two lessons 0:48:23.239 --> 0:48:26.120 were also learned during what would be the first epidemic 0:48:26.160 --> 0:48:29.480 of West Nile virus in North America, beginning in August 0:48:29.520 --> 0:48:33.319 of nineteen ninety nine. But that outbreak also carried with 0:48:33.400 --> 0:48:39.160 it another hugely important warning. Human health is wildlife health 0:48:39.320 --> 0:48:43.440 is domestic animal health is environmental health. It's all connected. 0:48:43.600 --> 0:48:49.000 What's that, It's all connected. What's that A one health approach, A. 0:48:49.120 --> 0:48:50.160 One health approach. 0:48:52.560 --> 0:48:56.160 So let's get into it. Do you remember the nineteen 0:48:56.239 --> 0:48:58.399 ninety nine West Nile virus outbreak at all? 0:48:58.719 --> 0:49:02.720 You know, I've I remember when West Nile virus became 0:49:02.920 --> 0:49:05.960 a thing because my dad had a pond in the 0:49:05.960 --> 0:49:08.920 backyard and it was like, oh no, we can't have 0:49:08.920 --> 0:49:12.160 a pond anymore because West now virus made it to California. 0:49:12.560 --> 0:49:14.640 Mm huh. Yeah. 0:49:14.719 --> 0:49:14.919 Yeah. 0:49:14.920 --> 0:49:18.000 I don't remember specifically, like the nineteen ninety nine one, 0:49:18.000 --> 0:49:22.080 but I remember suddenly it was like West Nile mosquitoes. Yeah, 0:49:22.120 --> 0:49:25.440 you know, put on that off whatever all the time. 0:49:26.120 --> 0:49:29.040 All I knew was that it appeared and then that 0:49:29.200 --> 0:49:29.480 was it. 0:49:29.719 --> 0:49:30.239 Yeah. 0:49:30.320 --> 0:49:33.160 So let me fill in some of the details. 0:49:33.200 --> 0:49:34.760 Some of our gaps and memory. 0:49:35.239 --> 0:49:35.479 Yeah. 0:49:35.560 --> 0:49:35.840 Yeah. 0:49:36.480 --> 0:49:39.600 So, beginning in the summer of nineteen ninety nine, all 0:49:39.680 --> 0:49:44.400 over New York City, crows started dropping dead. It was 0:49:44.440 --> 0:49:47.400 like dropping out of the sky, just dead. Everywhere you 0:49:47.440 --> 0:49:51.080 went you could find the carcasses of dead crows. And 0:49:51.160 --> 0:49:53.120 maybe if you lived in New York City at the time, 0:49:53.320 --> 0:49:56.200 you might have seen some of these dead crows and thought, 0:49:56.320 --> 0:50:00.240 oh gross, these poor crows, probably rat poison. Who knows, 0:50:00.600 --> 0:50:03.200 bad pizza? I don't know, and then went on with 0:50:03.280 --> 0:50:06.520 your day. But the sight of these crows brought a 0:50:06.560 --> 0:50:12.160 lot more alarm to one person, in particular, doctor Tracy McNamara, 0:50:12.680 --> 0:50:16.759 who was the lead pathologist at the Bronx Zoo. If 0:50:16.800 --> 0:50:20.360 these crows were dying of some kind of infectious disease, 0:50:20.640 --> 0:50:23.040 the birds at the zoo, some of which were rare 0:50:23.200 --> 0:50:27.239 or endangered, were at serious risk. And that risk soon 0:50:27.320 --> 0:50:29.960 became a reality when some of the zoo birds began 0:50:30.040 --> 0:50:33.799 to die, starting with a snowy owl. Oh no, And 0:50:33.840 --> 0:50:36.520 this definitely pointed towards an infectious agent. 0:50:36.640 --> 0:50:38.319 But like, what was it? 0:50:39.360 --> 0:50:42.720 Doctor McNamara examined some brain tissue from the dead birds 0:50:42.800 --> 0:50:45.719 under the scope to try to answer that question, and 0:50:45.960 --> 0:50:49.600 what she saw, in her own words, took her breath away. 0:50:50.040 --> 0:50:50.360 Wow. 0:50:50.480 --> 0:50:55.080 Quote, it was the worst encephalitis I'd seen in eighteen 0:50:55.200 --> 0:50:57.640 years as a comparative pathologist. 0:50:58.719 --> 0:51:00.840 Just yeah, staggering. 0:51:02.480 --> 0:51:06.160 Not far away at Flushing Hospital in Queens, an unusual 0:51:06.239 --> 0:51:10.560 number of encephalitis cases began coming in, some with paralysis 0:51:10.600 --> 0:51:13.600 and some leading to death, but these were in humans 0:51:13.719 --> 0:51:14.640 rather than birds. 0:51:14.719 --> 0:51:17.080 Just to clarify, and. 0:51:17.080 --> 0:51:20.800 These encephalitis cases were clustered enough in time and space 0:51:21.040 --> 0:51:24.560 to make an infectious disease specialist at the hospital, doctor 0:51:24.600 --> 0:51:28.399 Debbie Asns, wonder whether there might be a link among them, 0:51:29.280 --> 0:51:31.359 so she brought in the Department of Health to ask 0:51:31.440 --> 0:51:35.600 the patient's question after question about where they ate, what 0:51:35.760 --> 0:51:38.479 they ate, where they worked, where they lived, what train 0:51:38.560 --> 0:51:42.120 they rode, what shampoo they used, and so on. The 0:51:42.120 --> 0:51:46.080 only commonality among them seemed to be that they enjoyed 0:51:46.120 --> 0:51:49.239 spending a lot of time outside, especially in the evenings, 0:51:50.080 --> 0:51:53.720 and household surveys of where they lived showed that there 0:51:53.760 --> 0:51:58.439 had been a lot of mosquito breeding habitats around. Could 0:51:58.480 --> 0:52:01.799 it be a mosquito born out break? It had been 0:52:01.920 --> 0:52:05.040 a long time since something like that had happened in 0:52:05.080 --> 0:52:07.880 New York. Yeah, I remember, this was before Zeka. 0:52:08.000 --> 0:52:13.440 This was like way before, way before before. Yeah, this 0:52:13.600 --> 0:52:15.719 is like but it was. 0:52:15.680 --> 0:52:19.879 Still a possibility, like enough so that doctor Asnes sent 0:52:19.960 --> 0:52:22.560 off samples to the CDC to have them test for 0:52:22.680 --> 0:52:28.120 any known infectious agents, which side note deserves some major 0:52:28.160 --> 0:52:31.239 props because there are plenty of doctors who would have 0:52:31.320 --> 0:52:34.480 chalked up the cases to coincidence, like there isn't always 0:52:34.480 --> 0:52:37.040 an answer in medicine, and there are plenty of unexplained 0:52:37.040 --> 0:52:41.120 fevers or illnesses that resolve themselves without revealing what they 0:52:41.160 --> 0:52:44.640 really are. And so for doctor Asnes to send out 0:52:44.640 --> 0:52:47.760 those samples is like in many ways, I think going 0:52:47.840 --> 0:52:52.120 above and beyond and likely helped enact control measures earlier than. 0:52:52.040 --> 0:52:53.400 They would have otherwise. 0:52:54.760 --> 0:52:57.680 And so off those samples went to the CDC, and 0:52:58.040 --> 0:53:00.760 before long they came back with a match with an answer, 0:53:01.480 --> 0:53:05.520 Saint Louis and cephalitis virus. And this seemed like a 0:53:05.560 --> 0:53:10.000 reasonable explanation. Saint Louis and cephalitis virus is a rare 0:53:10.120 --> 0:53:14.440 mosquito born virus that can, as its name suggests, cause encephalitis, 0:53:14.480 --> 0:53:15.680 and it's a flabby virus. 0:53:16.719 --> 0:53:19.920 But that answer, which. 0:53:19.840 --> 0:53:22.560 Was now by this time reported in the news outbreak 0:53:22.560 --> 0:53:25.719 of Saint Louis and cephalitis, that didn't sit right with 0:53:25.880 --> 0:53:31.320 doctor Tracy and McNamara. After hearing about the human encephalitis cases, 0:53:31.960 --> 0:53:35.160 she felt very strongly that there was a link between 0:53:35.320 --> 0:53:38.440 those cases and the sick and dying birds at the zoo. 0:53:39.200 --> 0:53:41.560 But if she was right and there was such a link. 0:53:41.760 --> 0:53:45.360 It couldn't be Saint Louis and cephalitis virus because birds 0:53:45.400 --> 0:53:46.640 can't get that virus. 0:53:48.080 --> 0:53:49.200 And so she reached out to. 0:53:49.239 --> 0:53:53.120 The CDC with her concerns and urged them to test 0:53:53.200 --> 0:53:55.080 some of her samples to see if there was a 0:53:55.120 --> 0:53:59.319 match to the human samples. But the CDC turned her 0:53:59.360 --> 0:54:07.560 down really really okay, partly because it was a bureaucracy thing. Yeah, 0:54:07.560 --> 0:54:11.000 like the testing of animal samples, all animal health stuff 0:54:11.239 --> 0:54:14.719 that fell under the jurisdiction of like the USDA, I think, 0:54:15.360 --> 0:54:19.000 And it was a totally different like the CDC in 0:54:19.040 --> 0:54:21.080 some ways. They were like, well, we don't have the 0:54:21.120 --> 0:54:24.880 capabilities to do this. This isn't like we're not allowed 0:54:24.880 --> 0:54:27.279 to do this in the you know. 0:54:27.960 --> 0:54:31.279 Yeah, the job in trip. It's so interesting because as 0:54:31.320 --> 0:54:33.560 you were saying, like she reached out to the CDC, 0:54:33.640 --> 0:54:36.600 I was like, Wow, how does one just reach out 0:54:36.640 --> 0:54:39.480 to the CDC? Like that's a good question. 0:54:40.360 --> 0:54:43.319 I mean, I guess if you're like the lead pathologists 0:54:43.360 --> 0:54:44.800 at a zoo, you might have some. 0:54:44.960 --> 0:54:47.960 I would think you'd have an in somehow. Yeah, but 0:54:48.000 --> 0:54:51.560 it's a bummer that she couldn't get around whatever bureaucracy existed. 0:54:51.760 --> 0:54:54.960 It was bureaucracy. But I think the other part was 0:54:55.000 --> 0:54:58.200 that she kind of ran into a lot of resistance 0:54:58.200 --> 0:55:01.280 wherever she faced. And that's like, that's how she described 0:55:01.320 --> 0:55:05.239 it because at that time, like there was this prevailing 0:55:05.280 --> 0:55:09.520 attitude that, you know, human health and wildlife health weren't 0:55:09.560 --> 0:55:13.320 necessarily connected, and so the death of a few birds 0:55:13.320 --> 0:55:15.359 at a zoo like that doesn't have anything to do 0:55:15.400 --> 0:55:18.120 with the people sick with encephalitis at the hospital. Plus 0:55:18.120 --> 0:55:19.280 we already have an answer. 0:55:19.760 --> 0:55:24.680 I just it's a lot of times erin on this podcast, 0:55:24.719 --> 0:55:28.000 we have stories like that from like the eighteen hundreds 0:55:28.000 --> 0:55:30.200 where you look back and you're like, it was so obvious, 0:55:30.200 --> 0:55:32.200 how did you not see it? And like this was 0:55:32.440 --> 0:55:36.400 nineteen ninety nine. So it feels painful. 0:55:36.160 --> 0:55:40.960 It does, and yeah, and it's it's also just kind 0:55:41.000 --> 0:55:46.720 of like I think the aspect of the bureaucracy is frustrating. 0:55:46.239 --> 0:55:47.480 Oh my gosh. Yeah. 0:55:47.760 --> 0:55:53.360 So yeah, But doctor McNamara didn let that stand in 0:55:53.400 --> 0:55:57.160 her way her rejection from by the CDC, so she 0:55:57.360 --> 0:56:00.600 sought out some colleagues in the army. I'd asked them 0:56:00.640 --> 0:56:04.400 to test her samples. Awesome, and they did, and what 0:56:04.480 --> 0:56:09.080 they found was not Saint Louis encephalitis virus, but rather 0:56:09.320 --> 0:56:13.160 a virus that hadn't ever been detected in North America before, 0:56:14.200 --> 0:56:15.120 of course. 0:56:14.960 --> 0:56:17.040 West Nile virus West now virus. 0:56:17.719 --> 0:56:22.280 Suddenly the CDC became interested and stopped screening doctor McNamara's calls, 0:56:22.760 --> 0:56:28.760 just kidding. They re examined the samples from doctor Asna's patients, 0:56:28.920 --> 0:56:31.200 and sure enough West nolvirus. 0:56:31.840 --> 0:56:34.680 Yeah, so it's not surprising that it cross reacted. 0:56:34.880 --> 0:56:36.600 Oh yeah, not at all. That's like, I think that's 0:56:36.600 --> 0:56:40.880 a very reasonable thing for to happen. I guess, yeah, 0:56:40.920 --> 0:56:43.840 And so I'm not one hundred percent clear on the timeline, 0:56:44.239 --> 0:56:48.120 but I did watch an interview with doctor McNamara where 0:56:48.160 --> 0:56:50.560 she estimated that there was about a two or two 0:56:50.640 --> 0:56:54.080 and a half month delay resulting from the CDC not 0:56:54.239 --> 0:56:57.480 testing her samples. And so it's a couple of months 0:56:57.520 --> 0:57:00.960 where public health departments and wildlife health researchers could have 0:57:01.000 --> 0:57:03.840 gotten ahead of this virus and like to try to 0:57:03.880 --> 0:57:08.719 begin awareness campaigns and control efforts. And I think that, 0:57:09.040 --> 0:57:10.880 you know, one of the biggest lessons is that this 0:57:11.080 --> 0:57:15.280 nineteen ninety nine West Nile virus outbreak revealed how siloed 0:57:15.320 --> 0:57:18.800 we were, and in many ways still are in terms 0:57:18.840 --> 0:57:23.080 of monitoring the links between human, wildlife and environmental health. 0:57:23.360 --> 0:57:25.800 I feel like that's something we just touched upon in 0:57:25.840 --> 0:57:27.040 our anthrax episode. 0:57:27.080 --> 0:57:32.000 It absolutely is like what good is a canary or 0:57:32.120 --> 0:57:34.760 crow in the coal mine if you ignore it when 0:57:34.800 --> 0:57:38.400 it signals danger, or if you can't figure out what 0:57:38.480 --> 0:57:42.640 that danger is because you lack the diagnostic tools. This 0:57:42.760 --> 0:57:45.880 initial outbreak of westnyle virus in New York involved and 0:57:46.080 --> 0:57:49.800 estimated eighty two hundred human infections, eighty percent of which 0:57:49.840 --> 0:57:54.080 were asymptomatic, and the remaining twenty percent were mostly those 0:57:54.120 --> 0:57:57.080 with mild febrile illness, and then less than one percent 0:57:57.320 --> 0:58:01.640 develop this neuroinvasive disease. But in terms of confirmed cases, 0:58:01.720 --> 0:58:05.280 those numbers were a lot lower, sixty two cases I think, 0:58:05.320 --> 0:58:07.600 in seven deaths something around there. 0:58:08.040 --> 0:58:08.440 Very well. 0:58:09.160 --> 0:58:12.320 Yeah, the nineteen ninety nine outbreak in New York City 0:58:12.440 --> 0:58:15.960 was not an isolated event. It continued on to New 0:58:16.040 --> 0:58:20.320 Jersey and then to Connecticut, and it seemed likely that it. 0:58:20.240 --> 0:58:20.920 Was here to stay. 0:58:21.800 --> 0:58:25.840 The National surveillance program ARBONNET was created by the CDC 0:58:26.040 --> 0:58:29.320 and state health departments to monitor bird and human disease 0:58:29.760 --> 0:58:32.520 to be on the lookout for potential outbreaks of arboviral 0:58:32.560 --> 0:58:37.200 disease like West Nile, and one good indicator of an 0:58:37.280 --> 0:58:41.200 upcoming outbreak is the die off of birds preceding the 0:58:41.240 --> 0:58:44.400 emergence of West Nile virus in an area. And that's 0:58:44.520 --> 0:58:47.520 exactly what happened in two thousand and two in the 0:58:47.720 --> 0:58:51.680 huge epidemic of West Nile in North America, reaching all 0:58:51.720 --> 0:58:54.360 the way to Montana and Texas and as far north 0:58:54.400 --> 0:58:58.160 as Quebec and Ontario. And this dwarfed the nineteen ninety 0:58:58.240 --> 0:59:01.360 nine outbreak in New York with over forty one hundred 0:59:01.440 --> 0:59:05.240 confirmed cases of the disease and two hundred and eighty 0:59:05.280 --> 0:59:11.000 four deaths, and I don't know how many estimated infections, 0:59:11.680 --> 0:59:15.160 but with a lot of the cases of severe disease 0:59:15.480 --> 0:59:19.160 and just general illness happening in the midwest US, so 0:59:19.200 --> 0:59:19.960 like it had kind. 0:59:19.840 --> 0:59:22.240 Of shifted its distribution. 0:59:24.040 --> 0:59:26.640 In the period of just a couple of years, this 0:59:26.760 --> 0:59:31.680 virus had traveled incredible distances, but we still don't know 0:59:31.840 --> 0:59:35.920 exactly how it got to the US. It's possible that 0:59:36.000 --> 0:59:40.080 it was introduced from Israel, but the mechanism is unclear 0:59:40.600 --> 0:59:44.760 and we may never know for sure. But in the 0:59:44.840 --> 0:59:48.120 time since these epidemics, we have learned a lot about 0:59:48.160 --> 0:59:51.800 the virus and its ecology. We've learned that horses can 0:59:51.840 --> 0:59:54.360 become sick with the virus. We've learned that it can 0:59:54.400 --> 0:59:58.520 be transmitted through blood transfusions and organ transplantation through the 0:59:58.560 --> 1:00:04.200 placenta and breast milk. Environmental conditions are hugely important, like 1:00:04.280 --> 1:00:08.360 warmer temperatures mean a shorter time from infection to infectiousness 1:00:08.720 --> 1:00:12.000 in the mosquito, and they can also increase viral replication 1:00:12.160 --> 1:00:16.080 within those mosquitoes. So in cool weather, the mosquito has 1:00:16.120 --> 1:00:19.560 to live a longer time and in order to pass 1:00:19.600 --> 1:00:22.800 on the virus to humans, so it has to live 1:00:22.880 --> 1:00:26.280 longer to become infectious after feeding on the infected bird. 1:00:27.080 --> 1:00:30.520 Average rainfall years seem to provide suitable conditions or the 1:00:30.520 --> 1:00:35.240 best conditions for mosquito proliferation. Warm winters mean more mosquitoes 1:00:35.320 --> 1:00:39.680 survive over winter. All of these bits of information are 1:00:39.800 --> 1:00:42.640 like pieces of the West Nile virus puzzle. 1:00:43.200 --> 1:00:45.240 The more we gather, the more we. 1:00:45.200 --> 1:00:47.720 Can fit them together to get a better picture of 1:00:47.840 --> 1:00:51.720 why outbreaks happen, where and when they happen, the role 1:00:51.800 --> 1:00:55.440 that different bird species play in transmission, and how things 1:00:55.520 --> 1:00:58.280 like climate change and land use change may alter the 1:00:58.360 --> 1:01:00.160 landscape of disease risks. 1:01:00.080 --> 1:01:00.880 For this virus. 1:01:02.480 --> 1:01:06.200 And we are so excited to bring on a special 1:01:06.280 --> 1:01:09.080 guest to help us with a huge chunk of this 1:01:09.200 --> 1:01:12.720 West Nile virus puzzle. Yes, we told you it was coming, 1:01:13.120 --> 1:01:16.320 uh huh, And that is the bird part of the puzzle. 1:01:17.520 --> 1:01:20.240 We'll let her introduce herself right after this break and 1:01:20.280 --> 1:01:23.600 then after that, Aaron, I want to hear more about 1:01:23.640 --> 1:01:26.160 like West Nile virus in the world today. 1:01:26.200 --> 1:01:27.480 And I want to tell you about it. 1:02:00.760 --> 1:02:03.960 My name is Sarah Wheeler and I'm currently the biologist 1:02:04.000 --> 1:02:06.240 at Sacramento Yolo Mosquito. 1:02:05.800 --> 1:02:07.160 And Vector Control District. 1:02:07.960 --> 1:02:12.920 And at the district, I am now focused on applied 1:02:12.960 --> 1:02:17.440 research into mosquito control. But I started my journey on 1:02:17.480 --> 1:02:21.000 this path as an ornithologist and I've spent a lot 1:02:21.040 --> 1:02:24.720 of time investigating the role of wild birds and the 1:02:24.840 --> 1:02:29.480 spread of West now virus, the spread, amplification and maintenance 1:02:29.480 --> 1:02:33.000 of West now really and so I'm happy to talk 1:02:33.040 --> 1:02:34.160 some more about that today. 1:02:34.880 --> 1:02:38.120 Awesome, thank you so much for taking the time to chat. 1:02:38.640 --> 1:02:41.200 I just kind of want to start off by talking 1:02:41.200 --> 1:02:44.920 about the effects of Westnile virus on birds. So in 1:02:44.960 --> 1:02:48.040 this episode so far we have talked about the range 1:02:48.080 --> 1:02:51.960 of effects that westnle virus has had on humans, things 1:02:52.000 --> 1:02:54.960 like asymptomatic or mild disease all the way to these 1:02:55.000 --> 1:02:59.160 severe neurological complications or even death. So can you talk 1:02:59.240 --> 1:03:02.640 a bit about what infection looks like in birds and 1:03:02.800 --> 1:03:05.800 is there a similar wide clinical range of symptoms. 1:03:06.960 --> 1:03:10.880 There's absolutely a wide range of symptoms, and it can 1:03:10.920 --> 1:03:15.840 go from completely asymptomatic in some species or individuals, to 1:03:16.240 --> 1:03:19.360 debilitating to the point where the animal can't survive on 1:03:19.440 --> 1:03:24.440 its own, to completely fatal infections, and a lot of 1:03:24.440 --> 1:03:29.160 this can be somewhat generalized by the species. So we 1:03:29.280 --> 1:03:33.840 know that some species are more susceptible to westnil virus, 1:03:33.920 --> 1:03:38.240 So generally we think of passerines or songbirds being more 1:03:38.280 --> 1:03:41.720 susceptible to westnilvirus. But that is a huge range of 1:03:41.760 --> 1:03:46.400 bird species, and even within the range of songbirds, some 1:03:46.680 --> 1:03:50.760 are more refractory than others. And so for a bird 1:03:50.840 --> 1:03:53.240 that is going to deal with an infection, find you 1:03:53.240 --> 1:03:55.960 will never even know that they're infected. They might have 1:03:56.080 --> 1:03:59.479 a couple of days of virhemia or no viremia. That's 1:03:59.680 --> 1:04:02.920 virus circulating in the blood of the bird to the 1:04:02.960 --> 1:04:06.480 point where they could infect mosquitoes. They might not infect 1:04:06.560 --> 1:04:10.000 mosquitoes at all and not really become sick. 1:04:10.280 --> 1:04:13.120 To a bird that produces, you know. 1:04:13.160 --> 1:04:16.120 So much virus in its blood that it could infect 1:04:16.160 --> 1:04:19.600 any mosquito that feeds on it and it succumbs within 1:04:20.200 --> 1:04:21.480 four or five days. 1:04:21.880 --> 1:04:24.480 So yeah, it's a really wide range. 1:04:25.040 --> 1:04:29.520 Okay, So in the ones that are like severely impacted, 1:04:29.920 --> 1:04:32.200 what are some of the symptoms that they show. 1:04:32.920 --> 1:04:34.680 Yeah, so outward symptoms. 1:04:35.240 --> 1:04:37.959 If you see a bird with West nile, it might 1:04:38.040 --> 1:04:41.000 be kind of hunched and puffy looking. 1:04:41.480 --> 1:04:44.520 So we were doing some work with house. 1:04:44.320 --> 1:04:47.840 Finches and Westnoile virus and it turned out that they 1:04:47.840 --> 1:04:50.280 were sitting there just looking very puffed up, and that's 1:04:50.320 --> 1:04:53.000 a common symptom and a bird that's sick. And those 1:04:53.040 --> 1:04:56.160 birds actually had really low body temperature, so I think 1:04:56.160 --> 1:04:57.960 that it was having a hard time dealing with the 1:04:57.960 --> 1:05:03.880 infection and having trouble them regulating. Some birds develop acute 1:05:03.880 --> 1:05:09.320 neurological symptoms, so they get tremors or headpilts. So I 1:05:09.360 --> 1:05:12.880 think that sometimes birds that are in the transition period 1:05:12.920 --> 1:05:17.560 of just becoming very sick can actually just start acting weird. 1:05:17.920 --> 1:05:23.400 So we're studying the fatality events of crows in Davis, California, 1:05:24.080 --> 1:05:27.280 and it turned out that many of the crows that 1:05:27.800 --> 1:05:31.640 died of trauma actually were infected with West nile. So, 1:05:31.680 --> 1:05:33.480 I mean, a crow doesn't usually just get hit by 1:05:33.480 --> 1:05:36.520 a car, but if it's not feeling well, it might not. 1:05:37.000 --> 1:05:41.520 Get out of that gutter. Birds like raptors. 1:05:40.840 --> 1:05:44.640 Can actually develop ocular lesions, which means that they can 1:05:44.680 --> 1:05:48.320 clear the infection, but then they turn up at wildlife 1:05:48.320 --> 1:05:53.080 care centers or body condition because they can't hunt for themselves, right. 1:05:53.320 --> 1:05:56.200 So it's not necessarily that a lot of birds are 1:05:56.280 --> 1:05:59.520 dying outright, or maybe some birds are dying outright from 1:05:59.560 --> 1:06:02.520 infect but others are dying as a consequence of infection 1:06:02.680 --> 1:06:04.880 simply because they can't, like you said. 1:06:04.920 --> 1:06:07.200 Exist on their own or survive on their own anymore. 1:06:07.640 --> 1:06:09.000 It's affected their fitness. 1:06:09.440 --> 1:06:13.600 Wow, Okay, very interesting. And so you know, as you mentioned, 1:06:13.600 --> 1:06:16.120 there are some birds that seem to be more susceptible 1:06:16.160 --> 1:06:20.160 to West malavirus infection than others. Do we know anything 1:06:20.200 --> 1:06:23.600 about the reasons for these differences in susceptibility? 1:06:24.240 --> 1:06:27.600 Know what I really wish I knew this because it's 1:06:28.200 --> 1:06:30.960 it is a wide range, and like I said before, 1:06:31.040 --> 1:06:33.960 we think of it as being you know, taxa based, 1:06:34.120 --> 1:06:38.480 So crows birds in the crow family, so crows, jays, 1:06:38.640 --> 1:06:42.840 magpies are for the most part exquisitely sensitive to Westnow virus. 1:06:43.120 --> 1:06:47.200 They're very common dead bird programs. They you know, have 1:06:47.280 --> 1:06:49.080 higher mortality when exposed. 1:06:49.400 --> 1:06:50.320 They don't all die. 1:06:50.440 --> 1:06:52.640 We don't have a lot of evidence of crows surviving 1:06:52.680 --> 1:06:58.000 west now, but we definitely have antibody positive js and magpies. 1:06:58.080 --> 1:07:02.000 This does happen, so they via the infection, they produce antibodies, 1:07:02.040 --> 1:07:05.200 and that's something that we can detect in different cero surveys. 1:07:05.440 --> 1:07:11.720 But birds like pigeons, chickens. Chickens are actually really common 1:07:11.880 --> 1:07:14.800 sentinel birds for west Now virus surveillance. So we put 1:07:14.800 --> 1:07:17.960 them out in flocks and we bleed them every two 1:07:17.960 --> 1:07:20.920 weeks and see if they develop antibodies to west Now virus. 1:07:20.960 --> 1:07:25.800 And this was a really classic way for doing rbavirus surveillance, 1:07:25.880 --> 1:07:28.600 especially before you had PCR. You could put your chickens 1:07:28.640 --> 1:07:33.800 out and errology techniques have developed before PCR technique, so 1:07:33.880 --> 1:07:36.760 this was a really handy way of doing surveillance and 1:07:36.920 --> 1:07:41.560 chickens show no sign of infection. They don't infect mosquitoes. 1:07:41.560 --> 1:07:45.320 It's a total dead end post. So what is different 1:07:45.400 --> 1:07:49.240 between a chicken and a crow. I don't think we 1:07:49.360 --> 1:07:53.800 understand this, but there's something different. Whether or not it's 1:07:53.840 --> 1:07:57.440 some sort of pathogen effect where the virus is just 1:07:57.480 --> 1:07:59.960 not replicating as efficiently, or if it's at the bird 1:08:00.240 --> 1:08:02.800 is fighting it off more effectively, I don't. 1:08:02.880 --> 1:08:03.840 I don't think we know that. 1:08:04.680 --> 1:08:05.880 Yeah. Interesting. 1:08:06.680 --> 1:08:10.720 So a follow up question about susceptibility in birds with 1:08:10.840 --> 1:08:14.880 West Nile is about geography. So are there any patterns 1:08:14.920 --> 1:08:19.080 geographically in terms of susceptibility, Like are there do there 1:08:19.120 --> 1:08:23.960 tend to be more resistant birds in places where the 1:08:24.040 --> 1:08:27.360 virus has been circulating for you know, a really long time, 1:08:27.520 --> 1:08:29.639 like I'm talking on the scale of hundreds or thousands 1:08:29.640 --> 1:08:33.120 of years, versus places where the virus has been introduced 1:08:33.120 --> 1:08:35.400 more recently, such as in North America. 1:08:36.200 --> 1:08:38.760 I think that that is plausible. 1:08:39.240 --> 1:08:42.880 I mean, we don't see the mortality events where you know, 1:08:43.000 --> 1:08:46.759 west now virus first evolved that we see in North America. 1:08:46.880 --> 1:08:50.320 So our birds in North America are living with west 1:08:50.360 --> 1:08:54.360 now currently, like multiple generations have now been living with 1:08:54.439 --> 1:08:56.360 West Now and I don't know if we'll ever get 1:08:56.360 --> 1:09:01.040 to completely asymptomatic, but it's plausible to say that. But 1:09:02.240 --> 1:09:06.320 what that might look like in North America is an 1:09:06.360 --> 1:09:11.240 open question because it's not a static system. So how 1:09:11.400 --> 1:09:15.679 a bird deals with an infection, If it's able to 1:09:15.760 --> 1:09:18.599 fight that infection off and not develop as strong as 1:09:18.600 --> 1:09:21.840 a virehemia, then that would push the virus to being 1:09:21.880 --> 1:09:27.000 more virulent. So there's always that post pathogen interaction. And 1:09:27.080 --> 1:09:31.519 so West Nile, compared to other arboviruses in North America, 1:09:31.640 --> 1:09:35.320 has tended to be more virulent, and we thought that this, 1:09:35.560 --> 1:09:39.760 you know, helped to drive it into more refractory mosquito species. 1:09:40.200 --> 1:09:43.439 So it took a higher virehemia in order to get 1:09:43.479 --> 1:09:46.960 our native mosquitoes infected, and so that's kind of helped 1:09:47.080 --> 1:09:51.519 drive the system. And just over twenty years of West 1:09:51.560 --> 1:09:54.120 Nile virus, I think that we've seen some species that 1:09:54.320 --> 1:09:58.639 felt like they were getting more refractory, and it might 1:09:58.680 --> 1:10:00.800 be happening, but I don't know that we know that 1:10:01.080 --> 1:10:05.440 for sure. But West now virus transmission is not constant, 1:10:05.520 --> 1:10:09.720 it's not constant pressure, So you know a population that's 1:10:09.760 --> 1:10:12.960 under constant pressure might get a lot of west Now 1:10:13.040 --> 1:10:16.519 exposure for multiple years, and then we have two years 1:10:16.560 --> 1:10:18.880 of not a lot of west Now pressure, which allows 1:10:18.920 --> 1:10:21.160 that population to build back up. 1:10:21.240 --> 1:10:22.200 Perhaps you have. 1:10:22.200 --> 1:10:25.559 More open niches and more you know, nesting success, and 1:10:25.600 --> 1:10:28.959 so it allows populations to recover somewhat. 1:10:29.880 --> 1:10:33.120 Yeah, that's that's really fascinating. You do have to consider 1:10:33.160 --> 1:10:36.240 all the different components of the system and the cycle 1:10:36.280 --> 1:10:38.799 that it's not just about the bird and the virus. 1:10:38.800 --> 1:10:40.960 It's also about the mosquito and the bird and the 1:10:41.040 --> 1:10:44.400 virus and all of these moving parts that are difficult 1:10:44.400 --> 1:10:45.600 so sometimes get a handle on. 1:10:45.880 --> 1:10:48.000 Yeah, I mean the mosquito is a huge part of 1:10:48.040 --> 1:10:52.280 this whole situation. Like mosquito is in a way like 1:10:52.920 --> 1:10:58.200 the driving force of the whole transmission cycle. Because the 1:10:58.240 --> 1:11:02.439 mosquitoes that transmit west now would almost like nine times 1:11:02.439 --> 1:11:03.839 out of ten, prefer to feed. 1:11:03.640 --> 1:11:06.800 On a bird, so qelex. They really like to feed 1:11:06.800 --> 1:11:08.040 on birds. They prefer birds. 1:11:08.439 --> 1:11:10.400 So if you look at blood meal I d studies 1:11:10.439 --> 1:11:14.439 where people collect blood fed cuelex and you look at 1:11:14.439 --> 1:11:16.760 the DNA and the blood meal and identify what they 1:11:16.800 --> 1:11:18.680 fed on, you'll generally. 1:11:18.280 --> 1:11:19.599 See a bird species there. 1:11:19.960 --> 1:11:23.439 Even though nine times out of ten that QLX mosquito 1:11:23.520 --> 1:11:24.519 is going to feed on a bird. 1:11:24.600 --> 1:11:26.040 If a human is sitting out. 1:11:25.880 --> 1:11:29.479 There, you know, barbecuing or making it easy for the mosquito, 1:11:29.560 --> 1:11:34.120 the mosquito might just take advantage of that. So that's 1:11:34.160 --> 1:11:37.839 why it's predominantly a bird mosquito cycle, because the mosquitoes 1:11:37.840 --> 1:11:40.040 are predominantly feeding on the birds. The birds are the 1:11:40.080 --> 1:11:43.960 amplifying posts, and that's kind of how it cycles, with it, 1:11:44.080 --> 1:11:48.160 you know, occasionally spilling over into humans or horses. And 1:11:48.240 --> 1:11:50.080 I get the question a lot, like what about my 1:11:50.160 --> 1:11:53.240 dog or my cat, you know, and I think, I'm 1:11:53.400 --> 1:11:56.920 sure that they're bitten by infected mosquitoes, but we don't 1:11:56.960 --> 1:12:00.760 see any kind of reports of infection and cats, so 1:12:00.960 --> 1:12:02.920 probably just another dead end host. 1:12:03.240 --> 1:12:05.960 I'm like now brimming with a bunch of questions about 1:12:06.080 --> 1:12:09.240 mosquitoes and mosquito ecology and so is it really just 1:12:09.320 --> 1:12:12.679 sort of availability and opportunity of you know, whatever hosts 1:12:12.720 --> 1:12:15.000 are there for the mosquitoes, or do these tend to 1:12:15.040 --> 1:12:18.120 be more sylvatic species, like do they hang out mostly 1:12:18.160 --> 1:12:22.280 in wooded areas or are they also urban species? You know, 1:12:22.800 --> 1:12:26.640 what are some of those differences among competent mosquito species. 1:12:27.320 --> 1:12:30.280 So in our area, the two main vectors of western 1:12:30.320 --> 1:12:33.880 alvirus are kee Wex pipions and Keelex tarsalis. 1:12:34.400 --> 1:12:36.280 QX tarsalis tends. 1:12:36.000 --> 1:12:39.080 To breed more in rural areas, so in our area 1:12:39.160 --> 1:12:42.200 they breed really heavily in the rice fields that surround 1:12:42.280 --> 1:12:47.960 our urban centers. But Keelex pipions is totally an urban breeder. 1:12:48.160 --> 1:12:51.320 They love catch basins, So in your gutter, there's that 1:12:51.400 --> 1:12:54.320 little grate and there's like a little cement compartment down 1:12:54.360 --> 1:12:56.599 there that is supposed to catch the debris before it 1:12:56.640 --> 1:12:59.880 flows out the creek or whatever. Well, those almost all 1:13:00.280 --> 1:13:03.519 hold water, and so HeLEX pipians can really take advantage 1:13:03.520 --> 1:13:07.040 of that. A bucket of water in your backyard or 1:13:07.800 --> 1:13:11.080 you know, a green swimming pool or any source that they. 1:13:10.960 --> 1:13:13.320 Can take advantage of, and those happen quite. 1:13:13.040 --> 1:13:20.200 Regularly in urban areas, so you can definitely have both 1:13:20.360 --> 1:13:25.680 urban and rural transmission of wesnou virus. So sometimes in 1:13:25.840 --> 1:13:31.599 urban areas you have a concentration of very competent amplifying hosts. 1:13:31.600 --> 1:13:33.120 So in the city you see a lot of crows, 1:13:33.160 --> 1:13:36.040 you see a lot of jays, you see house finches, 1:13:36.200 --> 1:13:40.960 house sparrows, and all these species are competent amplifying hosts, 1:13:41.000 --> 1:13:42.760 and then you also have the mosquito, So you have 1:13:42.800 --> 1:13:48.240 a concentration of players that can contribute to an amplification cycle. 1:13:48.840 --> 1:13:52.040 When you get out into rural areas, you also have 1:13:52.200 --> 1:13:57.040 competent amplifying hosts out there, and great the tarsalus is 1:13:57.080 --> 1:13:59.440 out there. Sometimes you even have pippians and rural species. 1:13:59.760 --> 1:14:03.800 But you might have an introduction of more species, and 1:14:03.880 --> 1:14:07.880 sometimes the addition of greater species variety can have a 1:14:07.920 --> 1:14:12.479 diluting effect on effective transmission. So if you have a 1:14:12.600 --> 1:14:15.720 range of possible hosts and you know fifty percent of 1:14:15.760 --> 1:14:19.320 them are great amplifying hosts, that's going to lead to 1:14:19.320 --> 1:14:23.280 a different transmission cycle than a scenario where twenty five 1:14:23.360 --> 1:14:27.479 percent of them are great amplifying hosts. So that's why 1:14:27.520 --> 1:14:29.640 a lot of times you've seen West now be a 1:14:29.640 --> 1:14:32.160 little bit more urban in nature. I mean, it does 1:14:32.240 --> 1:14:33.960 happen rurally, absolutely, But. 1:14:34.840 --> 1:14:37.800 Yeah, So before I shift to talking about sort of 1:14:37.880 --> 1:14:41.360 more of the role that birds play in the transmission 1:14:41.400 --> 1:14:43.960 cycle of West malavirus, I want to just ask this, 1:14:44.040 --> 1:14:47.599 you know, overall question about the impact that West Nile 1:14:47.720 --> 1:14:51.080 virus has had on bird populations in North America since 1:14:51.080 --> 1:14:53.759 it's been introduced, and I'm sure that it's not consistent 1:14:53.800 --> 1:14:56.720 across the board, but have we seen substantial declines in 1:14:56.800 --> 1:14:59.519 some species and no impact on others. 1:15:00.400 --> 1:15:00.759 Yeah. 1:15:00.800 --> 1:15:05.960 So, especially when West Nile was tearing across the US 1:15:06.000 --> 1:15:08.559 and there was huge bird die offs across the US, 1:15:08.600 --> 1:15:11.760 a lot of people were very concerned about different bird species, 1:15:11.840 --> 1:15:14.160 like zoo collections were even getting hit, and you know, 1:15:14.240 --> 1:15:19.960 precious animals that you know might be sensitive or in decline, like, 1:15:20.040 --> 1:15:23.160 there was a lot of concern about what West Snow 1:15:23.360 --> 1:15:25.560 would do to those burd communities. 1:15:26.280 --> 1:15:29.040 And so myself and other. 1:15:28.920 --> 1:15:32.040 Researchers have spent some time trying to figure out what 1:15:32.200 --> 1:15:36.120 the impact of West Nile has been on these bird communities. 1:15:36.640 --> 1:15:37.760 And the kind of data that. 1:15:37.680 --> 1:15:40.200 You usually use for these kinds of analysis are some 1:15:40.280 --> 1:15:44.960 of these big bird census databases. So the Christmas Bird 1:15:45.040 --> 1:15:48.320 Count or the Breeding Bird Survey can kind of help 1:15:48.400 --> 1:15:53.000 you understand impacts on bird communities because they've been in 1:15:53.040 --> 1:15:55.599 place for a long time before West Nile even got here, 1:15:56.080 --> 1:15:58.960 and so you can look at the impact on those 1:15:59.000 --> 1:16:03.160 bird communities after west Now and see if there's been 1:16:03.439 --> 1:16:09.280 any kind of changes in their population dynamics. It's not perfect, right, 1:16:09.360 --> 1:16:13.439 There's other things that affect birds than West Nile. And 1:16:13.680 --> 1:16:18.280 I would say, especially like within the first five years, 1:16:18.320 --> 1:16:22.080 there are species that absolutely saw declines like there are 1:16:22.120 --> 1:16:26.240 there were declines. So a bird in our area of 1:16:26.280 --> 1:16:29.639 the yellow bill magpie, it's a bird that's only found 1:16:29.640 --> 1:16:32.240 in the central Valley of California, Like a huge part 1:16:32.240 --> 1:16:35.360 of its population was under West Nile virus pressure. Like 1:16:35.439 --> 1:16:38.680 you could see clear declines in that bird. They're kind 1:16:38.680 --> 1:16:42.000 of noisy birds. They're like a big black and white 1:16:42.000 --> 1:16:46.400 bird with a yellow bill, Like you notice them right. Anecdotally, 1:16:46.800 --> 1:16:49.120 people were saying, yeah, all of a sudden, the magpies 1:16:49.160 --> 1:16:49.880 were just gone. 1:16:50.120 --> 1:16:52.799 Well, you know, they. 1:16:52.400 --> 1:16:55.880 By their own nature probably helped preserve themselves a bit 1:16:56.040 --> 1:17:02.080 because not only can yellow bill magpiesself be somewhat nomadic 1:17:02.200 --> 1:17:05.960 in nature, like West Snile does not exert even pressure 1:17:06.040 --> 1:17:09.240 every year, and I think that that was what really 1:17:10.280 --> 1:17:13.200 allowed them to kind of level out and you know, 1:17:13.320 --> 1:17:17.120 get back on a better track with their population. So 1:17:17.160 --> 1:17:19.800 that you know, when West Nole first came in, like 1:17:19.840 --> 1:17:23.600 we had a multiple heavy years of pretty steady transmission 1:17:24.080 --> 1:17:27.160 and now it's like from year to year it's like, oh, 1:17:27.200 --> 1:17:29.760 it's a big year for Sacramento and it's not a 1:17:29.760 --> 1:17:33.200 big year for San Joaquin, and so it moves around, 1:17:33.360 --> 1:17:36.160 so it's not exerting that constant pressure. 1:17:35.760 --> 1:17:36.919 On that bird population. 1:17:37.640 --> 1:17:43.839 Crows definitely have had some impact, like they're the most sensitive. 1:17:43.960 --> 1:17:45.559 They're just exquisitely sensitive. 1:17:46.200 --> 1:17:49.759 But the odd thing about crows, and this isn't somewhat 1:17:49.760 --> 1:17:55.880 of a sidebar, they're always underrepresented in mosquito blood meal 1:17:56.000 --> 1:17:58.200 ID studies. So you're like, well, why we have all 1:17:58.200 --> 1:18:01.320 these dead crows if mosquitoes aren't them, And so that, 1:18:01.640 --> 1:18:04.280 I mean that may be a function of just how 1:18:04.360 --> 1:18:07.280 a crow lives its life or how those blood philip 1:18:07.320 --> 1:18:08.679 fed mosquitoes are collected. 1:18:08.840 --> 1:18:12.680 But yeah, I mean I think that West Nile has 1:18:12.720 --> 1:18:15.640 a huge impact on those species. 1:18:16.560 --> 1:18:19.280 Yeah, I had heard that about crows, But I think 1:18:19.280 --> 1:18:23.720 that's really curious about the lack of representation in the 1:18:23.760 --> 1:18:26.760 mosquito blood samples. 1:18:27.160 --> 1:18:28.280 Hmm. 1:18:28.400 --> 1:18:30.760 Yeah, that's a big story right there. And so it's 1:18:31.120 --> 1:18:35.639 been a source of debate about why we don't see 1:18:35.640 --> 1:18:38.800 them represented in bloodmulated idease days and is it that 1:18:38.840 --> 1:18:42.599 they're not really an important amplifying host despite the fact 1:18:42.640 --> 1:18:45.879 that they're like exquisitely sensitive to West Nile virus. 1:18:46.200 --> 1:18:47.679 And of the birds that. 1:18:47.880 --> 1:18:52.639 You have been investigated for their response to West Nile infection, 1:18:53.040 --> 1:18:56.160 their viremias are like some of the highest right, so 1:18:56.240 --> 1:18:59.200 they produce like the most virus in their blood. Makes 1:18:59.240 --> 1:19:03.280 them extremely competent amplifying hosts. So it's like, are they 1:19:03.320 --> 1:19:07.599 not important amplifying hosts with all this virus and a crow, 1:19:07.840 --> 1:19:11.519 especially if they'll sit there moribund for like two or 1:19:11.520 --> 1:19:14.439 three days before they actually succumb to infection, so they 1:19:14.439 --> 1:19:17.040 could just infect any mosquito that comes by to feed 1:19:17.080 --> 1:19:21.360 on them. And so, but when you do these blood 1:19:21.400 --> 1:19:25.200 meal I these studies, you find a lot of pigeons, 1:19:25.240 --> 1:19:28.679 you find doves, you find robins, you find a lot 1:19:28.680 --> 1:19:31.720 of other species like housewinches, And you're like, well, that 1:19:31.840 --> 1:19:35.240 leads me to believe that they're more important because that's 1:19:35.280 --> 1:19:36.680 what mosquitoes are feeding on. 1:19:37.800 --> 1:19:39.320 That is so interesting. 1:19:39.800 --> 1:19:43.200 Yeah, And so it's not as cut and dry as 1:19:43.520 --> 1:19:45.920 the birds that are the most susceptible and most abundant 1:19:45.960 --> 1:19:48.960 in a community or in an area are the ones 1:19:49.000 --> 1:19:51.240 that are going to play the biggest role in transmission 1:19:51.320 --> 1:19:54.240 or risk of exposure to humans, So are there these 1:19:54.280 --> 1:19:59.680 other ecological characteristics or certain species that do play a 1:20:00.400 --> 1:20:02.320 role as these reservoir hosts. 1:20:03.320 --> 1:20:04.360 So I feel like. 1:20:05.920 --> 1:20:09.240 I used to see this more clearly than I see 1:20:09.280 --> 1:20:09.679 it now. 1:20:10.000 --> 1:20:11.280 So I think that. 1:20:12.680 --> 1:20:15.240 Before we had a lot more information, we had, you know, 1:20:15.479 --> 1:20:20.040 some good baseline data on what types of virenias different 1:20:20.080 --> 1:20:25.240 species of birds kind of produced. So basically, the higher 1:20:25.280 --> 1:20:29.120 the virenia, the more likely that a greater number of 1:20:29.160 --> 1:20:31.639 mosquitoes will be infected to the point where they will 1:20:31.680 --> 1:20:35.440 then be able to transmit. So that is on itself 1:20:35.479 --> 1:20:38.320 a spectrum. So a mosquito needs to be able to 1:20:38.360 --> 1:20:42.160 take enough virus from the bird in order for it 1:20:42.280 --> 1:20:46.200 to become infected the point where then it can transmit. 1:20:46.960 --> 1:20:53.240 So birds that produce higher virenias ultimately infect more mosquitoes 1:20:53.280 --> 1:20:58.040 that can then themselves transmit. I used to think, okay, 1:20:58.160 --> 1:21:06.480 like pigeons, and they're not great amplifying hosts. Crows, jays, magpies, 1:21:07.320 --> 1:21:11.000 house pinches, house sparrows. These tend to be you know, 1:21:11.120 --> 1:21:15.880 pretty good amplifying hosts, especially the corvids. But it's it's like, 1:21:16.400 --> 1:21:19.200 once you get out of the box of looking at 1:21:19.200 --> 1:21:21.879 a figure on a paper of what's known about different 1:21:22.840 --> 1:21:26.720 viroemia profiles for different birds, Like it is a whole assemblage, 1:21:26.720 --> 1:21:29.559 it's a community of birds, and you know that even 1:21:29.760 --> 1:21:34.160 like though there's certain patterns that are followed for a 1:21:34.200 --> 1:21:37.960 given species, individual to individual are going to vary at 1:21:37.960 --> 1:21:40.200 this point. I mean, we never even used to test 1:21:40.240 --> 1:21:42.919 morning doves as a part of our dead bird surveillance 1:21:42.960 --> 1:21:45.720 program because it was like, well, they're not great amplifiers, 1:21:46.280 --> 1:21:48.320 so we don't even really need to look at them 1:21:48.320 --> 1:21:50.000 because chances are that they've died. 1:21:49.840 --> 1:21:50.479 Of something else. 1:21:50.880 --> 1:21:53.280 Well, on a whim, we decided to well, let's just 1:21:53.400 --> 1:21:56.640 test this. And it turns out that no, this species 1:21:56.720 --> 1:21:59.960 that's pretty much refractory to westnow virus infection can act 1:22:00.000 --> 1:22:03.240 actually still die of West Nile or it can die 1:22:03.760 --> 1:22:07.519 with a high amount of virus in its blood and tissues. 1:22:07.720 --> 1:22:10.639 Which you would think then, is that it actually succumbed 1:22:10.680 --> 1:22:13.800 to infection. Maybe it didn't, but it had a high 1:22:13.800 --> 1:22:19.439 amount of virus in its tissues. So it's created like 1:22:20.000 --> 1:22:23.360 less steady ground for assertions that I would have made 1:22:23.400 --> 1:22:25.120 in the past, like oh, they're not really playing a 1:22:25.200 --> 1:22:26.960 role if you have much a doves and maybe that 1:22:27.000 --> 1:22:30.040 would not be like a community that would produce as 1:22:30.120 --> 1:22:32.720 much virus as you would think it if there were 1:22:32.760 --> 1:22:36.400 more crows and j's and things like that around. So 1:22:37.720 --> 1:22:41.639 when you look at an area, there could be two 1:22:41.720 --> 1:22:45.519 hundred species in that area. Some of them will maybe 1:22:45.520 --> 1:22:49.200 never amplify a west Nile. But once you take that 1:22:49.360 --> 1:22:51.880 scale of birds and run it all the way up 1:22:51.920 --> 1:22:54.880 to say a crow is the most susceptible in a community, 1:22:55.080 --> 1:22:58.480 it's going to be a spectrum, right, It's a spectrum. 1:22:58.960 --> 1:23:05.160 And so as far as do certain assemblages of birds 1:23:05.360 --> 1:23:10.040 create a more risky west now virus scenario, I think 1:23:10.080 --> 1:23:14.599 that from a very high level view, urban areas tend 1:23:14.680 --> 1:23:18.439 to create assemblages of birds that can, you know, lead 1:23:18.520 --> 1:23:21.479 to amplifying events. 1:23:21.520 --> 1:23:26.160 But it's not ever the bird that is dangerous to people. 1:23:26.360 --> 1:23:27.280 It's the mosquito. 1:23:27.800 --> 1:23:32.040 Right, So people don't have to worry about protecting themselves 1:23:32.080 --> 1:23:35.320 from the birds. They have to protect themselves from the mosquito. 1:23:35.400 --> 1:23:38.519 And so that's why we really when we think about risk, 1:23:38.720 --> 1:23:40.000 we think about mosquitoes. 1:23:40.160 --> 1:23:41.160 And so we think. 1:23:41.000 --> 1:23:44.559 About, well, how many mosquitoes are in this area, like 1:23:44.880 --> 1:23:48.000 what proportion of them are infected with west now virus? 1:23:48.040 --> 1:23:51.000 Like what can we do to interrupt that transmission cycle 1:23:51.040 --> 1:23:53.960 because it's easier to deal with it and focus on 1:23:54.000 --> 1:23:58.479 the mosquito and it's the more direct link to exposure. Yes, 1:23:58.720 --> 1:24:05.000 bird community matter, it matters, but it's it's variable and 1:24:05.080 --> 1:24:10.800 it's hard to absolutely state what's the best amplifying community. 1:24:10.479 --> 1:24:14.040 You know, right, Ultimately it comes down to the mosquito 1:24:14.200 --> 1:24:16.639 and how many mosquitoes there are in a certain environment 1:24:16.680 --> 1:24:19.519 and how often humans are out and so on. 1:24:19.680 --> 1:24:20.040 Yeah. 1:24:20.080 --> 1:24:24.960 Absolutely, So let's talk a bit about bird migration. So 1:24:25.120 --> 1:24:28.480 we know that bird migration has an impact on potentially 1:24:28.520 --> 1:24:32.040 the geographic spread of West Nile virus and potentially other 1:24:32.280 --> 1:24:35.600 you know, bird associated pathogens. But how do things like 1:24:35.720 --> 1:24:40.439 the stress of migration impact bird communities or you know, 1:24:40.520 --> 1:24:44.000 the immune systems of birds and making them more susceptible 1:24:44.000 --> 1:24:45.920 potentially to West Nile virus. 1:24:46.720 --> 1:24:52.960 Yeah, so migration has been definitely a thing that we've 1:24:53.120 --> 1:24:56.040 spent a lot of time thinking about. So there is 1:24:56.040 --> 1:24:59.240 a somewhat of a mystery with West Nile and that's 1:24:59.400 --> 1:25:02.760 where it does go in the winter. So overwintering mechanisms 1:25:02.800 --> 1:25:07.320 for Westnile virus are not well understood. It was always 1:25:07.439 --> 1:25:12.439 a possibility that West snile was overwintering, you know, down 1:25:12.720 --> 1:25:15.320 somewhere where it's warmer where you could have year round 1:25:15.360 --> 1:25:21.000 transmission and then reintroduction events were kind of by migrating 1:25:21.040 --> 1:25:24.120 birds bringing it into new areas every year, and maybe 1:25:24.120 --> 1:25:28.360 that could attribute to why we see it flare up 1:25:28.400 --> 1:25:32.120 in different places from year to year. Looking at the 1:25:32.200 --> 1:25:35.920 genetics of the virus, this is not really supported, but 1:25:36.320 --> 1:25:37.280 we did spend a. 1:25:37.200 --> 1:25:40.439 Lot of time looking at migratory birds to kind of 1:25:40.479 --> 1:25:43.679 figure out if they were spreading the virus around. 1:25:44.320 --> 1:25:48.280 At some point I was down at the Coachella Valley, 1:25:48.360 --> 1:25:50.880 like along the Sultan Sea, and every year we would 1:25:50.960 --> 1:25:53.760 go down there to collect as many migratory birds as 1:25:53.760 --> 1:25:57.559 we possibly can and collect a small blood sample and 1:25:57.680 --> 1:26:00.639 test that blood sample for both antibodies and. 1:26:02.760 --> 1:26:03.559 Viral particles. 1:26:03.560 --> 1:26:06.519 Basically, does the has this bird been exposed to West 1:26:06.560 --> 1:26:10.320 Nile and is it currently infected. So it's a long 1:26:10.360 --> 1:26:14.599 shot looking for a virehemia, especially in a migrating bird, 1:26:14.720 --> 1:26:18.760 because migration is a very costly event. 1:26:18.560 --> 1:26:19.280 For those birds. 1:26:19.320 --> 1:26:22.080 So for them to be able to be fit enough 1:26:22.360 --> 1:26:25.800 to migrate while acutely infected. 1:26:25.920 --> 1:26:28.679 Is I don't know if that's possible. 1:26:29.280 --> 1:26:31.800 It may be I mean, birds are amazing it could 1:26:31.840 --> 1:26:35.120 they could do it, especially for short hops, maybe like 1:26:35.160 --> 1:26:38.200 from one stop to the next, they might get infected 1:26:38.240 --> 1:26:39.519 and then be able to carry it to. 1:26:39.479 --> 1:26:40.080 The next hop. 1:26:40.600 --> 1:26:43.240 And then if it's a species that's so refractory to 1:26:43.600 --> 1:26:48.200 West Nile that it's able to migrate in an infected state, like, 1:26:48.320 --> 1:26:49.479 how is that going. 1:26:49.320 --> 1:26:53.320 To play a role in a transmission events. 1:26:53.800 --> 1:26:58.120 So there have been other researchers that have found some 1:26:58.240 --> 1:27:03.960 kind of indication of birds migrating wall infected. So I'm 1:27:04.000 --> 1:27:06.479 sure it happens, But when we looked at the data 1:27:07.040 --> 1:27:09.880 for the birds coming in and the birds that were here, 1:27:10.600 --> 1:27:15.080 it just really seemed like the majority of the infection 1:27:15.200 --> 1:27:18.760 was happening here. So when we did find migrants that 1:27:18.840 --> 1:27:22.840 were infected with West Nile virus, they were heading back 1:27:22.960 --> 1:27:26.519 down south. They weren't heading north. They had been here 1:27:26.720 --> 1:27:30.280 all summer and were heading back down to their Central 1:27:30.280 --> 1:27:35.439 American overwintering grounds, and they had already been exposed. And 1:27:35.479 --> 1:27:40.240 so it really seemed like it wasn't migratory birds that 1:27:40.320 --> 1:27:44.800 were constantly receding infection just by what we were observing 1:27:44.960 --> 1:27:49.040 with you know, Westnile virus activity in the birds that 1:27:49.120 --> 1:27:53.080 it seemed like there was something that was overwintering locally 1:27:53.640 --> 1:27:56.840 and flaring up, and then as migrants were coming through, 1:27:57.360 --> 1:27:59.960 there was always the potential that they could be exposed 1:28:00.080 --> 1:28:01.679 and then hop it to the next location. 1:28:02.960 --> 1:28:04.879 That is very interesting. 1:28:04.920 --> 1:28:08.519 It kind of turns a bit like on the narrative 1:28:08.600 --> 1:28:10.640 that is so like, oh, well, you know birds that 1:28:10.680 --> 1:28:12.840 move from one place to another, and it makes it so. 1:28:12.840 --> 1:28:13.840 Easy for it to spread. 1:28:13.880 --> 1:28:17.680 It might not necessarily be why we see, you know, 1:28:18.040 --> 1:28:22.760 these events happening, and so on that note about how 1:28:22.840 --> 1:28:26.240 long or is there any sort of window during which 1:28:26.400 --> 1:28:29.479 in an infection there is circulating virus in the birds 1:28:29.479 --> 1:28:30.960 that are susceptible. 1:28:30.439 --> 1:28:32.240 And do seem to have like this vireemia. 1:28:32.400 --> 1:28:35.080 Is there a length of time during which you can 1:28:35.160 --> 1:28:35.880 collect virus. 1:28:36.840 --> 1:28:40.600 So if you're looking at a bird who's just been infected, 1:28:40.800 --> 1:28:44.280 by about two days you can detect virus in the blood, 1:28:44.800 --> 1:28:48.519 and then by about seven days, if it's not cleared, 1:28:49.240 --> 1:28:53.160 it's most likely not going to survive, okay. 1:28:53.320 --> 1:28:56.720 And then is there you know, lasting immunity following or 1:28:56.720 --> 1:28:58.080 can a bird get reinfected? 1:28:58.400 --> 1:29:00.920 It seems to be lasting community. 1:29:01.640 --> 1:29:02.000 Okay. 1:29:02.439 --> 1:29:06.080 So, as someone who works in the applied you know 1:29:06.160 --> 1:29:10.160 side of things and has this research background as well. 1:29:10.479 --> 1:29:14.360 What do you see as the biggest challenges to West 1:29:14.360 --> 1:29:15.439 nolevirus control? 1:29:16.280 --> 1:29:19.640 Honestly, for West nolevirus, we have to be able to 1:29:19.760 --> 1:29:25.439 have good effective surveillance methods. We have to have effective 1:29:25.479 --> 1:29:30.559 mosquito control tools, and so thankfully we've gotten a very 1:29:30.560 --> 1:29:35.040 efficient system for how mosquitoes are trapped and how they're tested. 1:29:35.840 --> 1:29:40.599 These are kind of pretty well worked out. But at 1:29:40.600 --> 1:29:46.560 this point in mosquito control, there are two active ingredients 1:29:46.760 --> 1:29:50.760 that are used for controlling mosquitos. So you have pyriethrins 1:29:50.760 --> 1:29:53.320 and pyreethroids, and you have organophosphates. 1:29:53.320 --> 1:29:57.040 So these are the insecticide classes and they're. 1:29:56.840 --> 1:30:01.719 Used in many many other fields, common in agriculture. They're 1:30:01.720 --> 1:30:04.799 common like if that pest control guy comes by your house, 1:30:04.920 --> 1:30:07.040 it's like, oh, you know, you have spiders all over 1:30:07.200 --> 1:30:11.439 I could spray for that. Well, they're spraying, but we're spraying. 1:30:11.600 --> 1:30:16.080 And so insecticide resistance is the growing problem and so 1:30:16.320 --> 1:30:19.479 as we move forward, we're going to have we're going 1:30:19.560 --> 1:30:22.880 to have to find creative solutions for how to break 1:30:22.920 --> 1:30:28.120 that transmission cycle through effective mosquito control. And this will 1:30:28.120 --> 1:30:31.800 continue to be a problem moving forward because I mean, 1:30:32.400 --> 1:30:37.360 mosquito control is a small slice of the you know, 1:30:37.439 --> 1:30:43.080 insecticide usage pie especially public health mosquito control like applications. 1:30:43.479 --> 1:30:47.839 So there aren't generally products designed especially for mosquito control 1:30:48.040 --> 1:30:51.240 because it's like it's not the largest market. You know, 1:30:52.040 --> 1:30:55.600 there are innovations that are coming out. So for a 1:30:55.640 --> 1:30:59.400 species eighties of gypty, which is a terrible vector around 1:30:59.439 --> 1:31:01.040 the world, spreads dangi and. 1:31:01.080 --> 1:31:03.160 Zika and chinkgunya. 1:31:03.479 --> 1:31:07.320 It's been invasive in a lot of areas of California. 1:31:07.439 --> 1:31:10.200 So we're now dealing with the gippi in California and 1:31:10.680 --> 1:31:14.280 throughout California. And so there's a lot of talk now 1:31:14.360 --> 1:31:18.200 about well, can we you know, use sterile insect programs to. 1:31:18.200 --> 1:31:19.480 Control these mosquitoes. 1:31:19.520 --> 1:31:22.479 And I think that that that's being used more and more, 1:31:22.640 --> 1:31:26.360 like it's it's still an emerging option and it might 1:31:26.439 --> 1:31:29.719 not be like what we can use for qlex control, 1:31:30.080 --> 1:31:34.000 but it's an example of thinking of new solutions to 1:31:34.120 --> 1:31:36.800 old problems. And I think that that's what we're going 1:31:36.880 --> 1:31:39.920 to have to continue to do moving forward, is think 1:31:39.960 --> 1:32:09.120 outside the box and you know, push the envelope. 1:32:09.400 --> 1:32:13.800 Thank you so much. That was Awesome. We knew that 1:32:13.800 --> 1:32:15.120 we were missing such a big part. 1:32:15.600 --> 1:32:21.679 I mean, I learned a lot, so much, so tell 1:32:21.680 --> 1:32:27.080 me more. Let's hear even more. So we'll just now 1:32:27.120 --> 1:32:32.200 focus on west now virus mostly in humans and look at. 1:32:31.920 --> 1:32:37.120 The big picture. Shall we focusing first on North America, 1:32:37.400 --> 1:32:42.200 since that's where we ended your section erin. Since west 1:32:42.200 --> 1:32:44.840 now virus made its debut in New York in nineteen 1:32:44.920 --> 1:32:50.559 ninety nine, the virus has resulted in over forty eight 1:32:50.680 --> 1:32:57.680 thousand reported cases in the US, twenty four thousand of 1:32:57.800 --> 1:33:01.720 those have been neuroinvasive, and it has resulted in over 1:33:01.800 --> 1:33:03.559 twenty three hundred deaths. 1:33:04.640 --> 1:33:05.240 Wow. 1:33:05.720 --> 1:33:11.880 Yeah in about twenty years now. It's estimated that the 1:33:11.960 --> 1:33:16.840 true number of infections is over seven million human infections 1:33:16.920 --> 1:33:22.240 in the continental United States. Wow. Wow, I just got it. 1:33:22.280 --> 1:33:24.840 Can just keep saying wow, That's all we can say. 1:33:26.600 --> 1:33:30.000 It's by far one of the most important zoanotic diseases 1:33:30.160 --> 1:33:33.240 and one of the most important causes of viral especially 1:33:33.360 --> 1:33:38.439 vector born encephalitis in the US since its introduction, and 1:33:38.560 --> 1:33:41.040 like you said, Aaron, it has spread throughout the entire 1:33:41.360 --> 1:33:45.559 United States. It's present throughout all of North America, It's 1:33:45.840 --> 1:33:48.840 likely present in Central and South America as well, but 1:33:48.920 --> 1:33:53.000 we don't have great data on Central and South America. 1:33:53.439 --> 1:33:58.040 Whether that's because it's overshadowed by other infections that look similar, 1:33:58.120 --> 1:34:01.640 like maybe Dengey fever, or whether it's there but at 1:34:01.760 --> 1:34:04.280 very low levels, or it's just not being reported, we 1:34:04.320 --> 1:34:07.599 don't really know, but we don't have good data on it. 1:34:08.520 --> 1:34:13.599 But even within the US, while like over fifty percent 1:34:13.720 --> 1:34:18.280 of counties in the US have reported at least one 1:34:18.400 --> 1:34:25.320 case over the course of time, they're not evenly distributed. 1:34:25.360 --> 1:34:29.479 Like cases are not evenly distributed, and outbreaks tend to 1:34:29.560 --> 1:34:33.599 happen in like discrete areas that vary a lot year 1:34:33.600 --> 1:34:39.160 to year. So overall, the actual number of reported cases 1:34:39.200 --> 1:34:44.000 in the US since its introduction has been it varies 1:34:44.040 --> 1:34:46.400 a lot year to year, but it hasn't necessarily been 1:34:46.479 --> 1:34:49.920 steadily growing or anything like that. But you do see 1:34:49.920 --> 1:34:52.040 a lot of year to year variation and a lot 1:34:52.040 --> 1:34:54.800 of geographic variation, like one year you'll have a whole 1:34:54.800 --> 1:34:58.320 bunch in Montana and another year a whole bunch somewhere else, 1:34:58.360 --> 1:35:03.760 et cetera. And it's not just humans, of course. Westnlvirus 1:35:03.840 --> 1:35:07.519 is a substantial animal pathogen in the US. It's caused 1:35:07.560 --> 1:35:12.680 over twenty eight thousand cases in horses and mortality that 1:35:12.720 --> 1:35:15.880 we know of in over three hundred bird species, like 1:35:15.920 --> 1:35:19.800 we heard a lot about already. In Canada, over five 1:35:19.880 --> 1:35:26.040 thousand human infections have been reported, and across Europe, outbreaks 1:35:26.120 --> 1:35:31.240 happen almost every year, but the biggest outbreak, especially in 1:35:31.280 --> 1:35:35.120 Europe by far, was in twenty eighteen, when there were 1:35:35.240 --> 1:35:40.600 over fifteen hundred cases that were reported across Europe. That 1:35:40.760 --> 1:35:44.160 was over seven times as many cases as had been 1:35:44.200 --> 1:35:49.360 reported in the previous seven years. Dang, right, in one 1:35:49.439 --> 1:35:54.840 single year. And so whenever we see outbreaks like this 1:35:55.000 --> 1:35:58.120 that happen, like really big outbreaks all of a sudden, 1:35:58.920 --> 1:36:02.920 especially of a vector born disease, we have to think about, like, 1:36:03.000 --> 1:36:08.080 what are the factors environmentally that are impacting this? And 1:36:08.120 --> 1:36:10.280 Aarin you kind of touched on this a little bit, 1:36:11.600 --> 1:36:13.320 but we're going to get into it a little bit more. 1:36:13.600 --> 1:36:16.400 Oh yeah, and then of course we're going to talk 1:36:16.439 --> 1:36:24.120 about climate change. So, like many, if not all, of 1:36:24.160 --> 1:36:26.719 the vector born diseases that we've covered on this show, 1:36:27.600 --> 1:36:32.479 it's not entirely clear how climate change either is going 1:36:32.520 --> 1:36:35.559 to affect or has already begun to affect West Nile 1:36:35.640 --> 1:36:41.679 virus incidents, prevalence, and also distribution. But we can gather 1:36:41.720 --> 1:36:44.639 at least a little bit of information based on especially 1:36:44.680 --> 1:36:47.720 that twenty eighteen Europe outbreak as well as just what 1:36:47.800 --> 1:36:52.160 we know about the mosquito and the virus. So, given 1:36:52.479 --> 1:36:57.280 that West Nile virus is mostly transmitted by mosquitos in 1:36:57.320 --> 1:37:02.680 the genus Qlex, their natural ecology is such that in 1:37:02.720 --> 1:37:06.960 an increasingly warm climate, it's very likely that that type 1:37:06.960 --> 1:37:10.600 of climate will increase both the abundance of these mosquitoes 1:37:10.720 --> 1:37:14.920 as well as increase their overall distribution. And like you mentioned, Aaron, 1:37:15.120 --> 1:37:19.080 if they're better at harboring virus in warmer climates compared 1:37:19.120 --> 1:37:21.919 to colder climates where they're maybe not as good a vectors, 1:37:22.320 --> 1:37:23.400 that's important as well. 1:37:23.720 --> 1:37:26.599 Oh yeah, that's that's not good news. 1:37:27.080 --> 1:37:31.920 No, it's really not. And that outbreak in Europe in 1:37:31.960 --> 1:37:36.040 twenty eighteen, it turns out that that year was not 1:37:36.160 --> 1:37:39.960 only one of the hottest years ever recorded, it was 1:37:40.080 --> 1:37:43.920 also a very very wet spring that was followed by 1:37:43.960 --> 1:37:48.080 a summer drought, which likely led to a very early 1:37:48.320 --> 1:37:52.920 expansion of the Qlex mosquitoes, which led to an increase 1:37:53.000 --> 1:37:56.920 in viral transmission. So what we saw that year was 1:37:57.000 --> 1:38:00.799 cases being reported earlier in the year than ever before, 1:38:01.520 --> 1:38:04.160 and then an outbreak that was the largest ever recorded, 1:38:04.439 --> 1:38:07.719 more cases like I said in the previous seven years, 1:38:09.080 --> 1:38:13.240 and over a larger geographic distribution than had been previously recorded. 1:38:13.560 --> 1:38:18.200 That year alone, cases were reported in Austria, Bulgaria, Croatia, Cyprus, 1:38:18.200 --> 1:38:26.080 Czech Republic, France, Greece, Hungary, Italy, Portugal, Romania, Serbia, Slavinia, Spain, Turkey, everywhere. 1:38:27.720 --> 1:38:28.320 Yeah. 1:38:28.560 --> 1:38:32.240 So, despite its global prevalence, despite it being such a 1:38:32.280 --> 1:38:36.000 common cause of mosquito born infection in the US for 1:38:36.040 --> 1:38:39.839 over twenty years, we still don't have any specific treatments, 1:38:40.280 --> 1:38:43.200 and we still don't have any licensed human vaccines. 1:38:44.479 --> 1:38:47.880 And with every year, I feel like becoming the hottest 1:38:47.960 --> 1:38:49.120 year on record. 1:38:49.000 --> 1:38:53.360 Right, yeah, every year, Yeah, year it feels like this one. 1:38:53.720 --> 1:38:57.160 There are at least four different animal vaccines, I think 1:38:57.240 --> 1:39:02.040 primarily for horses, and there have been Phase one and 1:39:02.080 --> 1:39:04.800 two studies of human vaccines, but there haven't been any 1:39:04.960 --> 1:39:09.880 Phase three or like the larger efficacy studies, And it 1:39:09.960 --> 1:39:13.400 seems mostly because there's not a market for it financially, 1:39:13.400 --> 1:39:17.600 which is so frustrating and what's even more frustrating is 1:39:17.640 --> 1:39:21.400 that we have vaccines for a lot of other flavaviruses 1:39:21.720 --> 1:39:24.840 like yellow fever virus. We have a vaccine Japanese and 1:39:24.840 --> 1:39:27.880 ccephalitis virus. We have a vaccine. Now. We even have 1:39:27.920 --> 1:39:32.960 a vaccine for Dengey virus. Apparently from a paper from 1:39:33.000 --> 1:39:36.880 twenty nineteen, there have been at least six different candidates 1:39:36.920 --> 1:39:39.640 of vaccines that have gone through these phase one and 1:39:39.680 --> 1:39:42.880 two trials. At least two of them seem to produce 1:39:42.920 --> 1:39:46.080 good immunity after a single dose, which is what would 1:39:46.120 --> 1:39:48.600 be needed for it to be a cost effective vaccine. 1:39:49.680 --> 1:39:53.840 None of the animal or the horse vaccines are single dose. 1:39:53.880 --> 1:39:56.879 They all require multiple doses as well as annual boosters. 1:39:57.200 --> 1:40:00.840 Oh okay, so, but there is at least promise, I think, 1:40:00.880 --> 1:40:04.400 both in terms of the immunology of West Nile virus 1:40:04.520 --> 1:40:07.320 and of flavaviruses in general, and then the fact that 1:40:07.360 --> 1:40:11.160 at least we have vaccines in phase one phase two trials. 1:40:11.200 --> 1:40:15.240 It seems to be kind of like a funding issue, etc. 1:40:16.920 --> 1:40:20.519 But in general, because of this lack of vaccine, control 1:40:20.560 --> 1:40:24.719 efforts really rely on prevention of infected mosquitos, So things 1:40:24.760 --> 1:40:29.479 like integrative pest management mosquito infection, like you mentioned, Aaron, sentinel, 1:40:29.479 --> 1:40:33.879 bird surveillance and all of that to try and reduce 1:40:33.920 --> 1:40:38.439 the prevalence of infected adult mosquitoes. And that, my friends, 1:40:38.920 --> 1:40:40.000 that's West Nile virus. 1:40:40.680 --> 1:40:41.799 That's West Nile virus. 1:40:42.800 --> 1:40:45.000 That was a fun one, Aaron. I learned a lot. 1:40:45.840 --> 1:40:48.840 Yeah, it was a really interesting one. I can't believe 1:40:48.840 --> 1:40:50.200 we hadn't done this yet. 1:40:50.720 --> 1:40:57.320 Hey, we did it now, We did it now. And yeah, sources, sources. 1:40:57.880 --> 1:40:59.840 I have a lot of papers I'm going to shout 1:40:59.840 --> 1:41:05.000 out just too, and one is by Savar from two 1:41:05.040 --> 1:41:10.479 thousand titled Westnile Virus and Historical Overview. And the other 1:41:10.560 --> 1:41:13.160 that I wanted to shout out for fun is by 1:41:13.320 --> 1:41:16.519 our PhD advisor, doctor Brian Allen. 1:41:16.840 --> 1:41:20.639 Yeah, yeay, and that is Alan at all. 1:41:20.479 --> 1:41:23.760 From two thousand and nine titled Ecological Correlates of Risk 1:41:23.840 --> 1:41:26.599 and Incidents of West Nile Virus in the United States. 1:41:27.439 --> 1:41:31.360 And I also watched, as I mentioned, several videos on 1:41:31.600 --> 1:41:35.040 West Nile virus and I will post a links to these. 1:41:35.360 --> 1:41:38.160 There were a couple ones that were especially helpful. West 1:41:38.200 --> 1:41:42.200 Nile Virus the first decade by Richard Ayler. One on 1:41:42.320 --> 1:41:45.559 PBS West Nyle outbreak in New York City and then 1:41:45.600 --> 1:41:49.559 also a great interview with Tracy McNamara and this video 1:41:49.600 --> 1:41:52.040 titled one Health and the Lessons Learned from the nineteen 1:41:52.120 --> 1:41:55.160 ninety nine West Snyle Outbreak, and that is by Microbe World. 1:41:56.160 --> 1:41:58.960 I also had a good number of papers a couple 1:41:58.960 --> 1:42:02.240 of my favorites for the overview of West Nile virus. 1:42:02.920 --> 1:42:06.280 We're both titled West Nile Virus one from the Lancet 1:42:06.320 --> 1:42:08.839 Neurology two thousand and seven and one from the Lancet 1:42:08.880 --> 1:42:11.640 Infectious Disease in two thousand and two. So kind of 1:42:11.720 --> 1:42:14.719 older papers but still really good. If you want more 1:42:14.800 --> 1:42:19.559 info on the development of vaccines, there was a paper 1:42:19.640 --> 1:42:23.040 called twenty years of Progress towards West Nile Virus Vaccine 1:42:23.040 --> 1:42:27.240 development in Viruses from twenty nineteen. And we'll post all 1:42:27.280 --> 1:42:30.280 of our sources from this episode and every one of 1:42:30.280 --> 1:42:33.080 our episodes on our website, This podcast will Kill You 1:42:33.120 --> 1:42:33.599 dot Com. 1:42:34.000 --> 1:42:39.080 We will thanks again so much to the amazing guests 1:42:39.160 --> 1:42:42.800 for this episode. We so appreciate you coming on to 1:42:42.880 --> 1:42:43.639 chat with us. 1:42:43.880 --> 1:42:48.120 Yeah, thank you. Thank you also to Bloodmobile, who provides 1:42:48.120 --> 1:42:51.719 the music for this episode and all of our episodes. 1:42:51.640 --> 1:42:54.960 And thank you to exactly Right, of whom we are 1:42:55.040 --> 1:42:58.680 a very proud member, and thank you to you listeners. 1:42:59.280 --> 1:43:02.360 We really love making this podcast, so thanks for listening 1:43:02.400 --> 1:43:02.760 to it. 1:43:03.160 --> 1:43:06.800 Yeah, and a special shout out also to our amazing, 1:43:06.960 --> 1:43:09.560 incredible supporters on Patreon. 1:43:09.840 --> 1:43:11.480 We love you. 1:43:11.479 --> 1:43:15.920 You're amazing, and everyone you only have a few more 1:43:15.960 --> 1:43:19.759 seconds to wait until your ears get to be blessed 1:43:20.320 --> 1:43:25.879 with the joyous sounds of mc Bugsy and West Nile Story. 1:43:26.320 --> 1:43:31.120 West Nile Story, Bring us out, Aaron, wash your hands. 1:43:31.439 --> 1:43:38.680 You've filthy animals. 1:43:39.040 --> 1:43:42.000 Who's heard of West Now pate it may not realize it, 1:43:42.080 --> 1:43:44.600 but it's inside of mosquitoes and they get credits of 1:43:44.680 --> 1:43:47.200 people to cover up rock rebell it, get rid of 1:43:47.240 --> 1:43:50.160 standing water. Mosquito bites can be more than just a bomb. 1:43:51.240 --> 1:43:54.120 No vaccine to protect, no medication to treat it. That 1:43:54.240 --> 1:43:57.759 means attention to prevention is the challenge. So me it empty, scrub, 1:43:57.800 --> 1:44:00.479 turn over, cover tip and toss out containing. Clean up 1:44:00.479 --> 1:44:02.880 the yard once a weaken your lippy, best life. Later 1:44:03.120 --> 1:44:06.320 long loose like colored clothes, so no skins exposed to 1:44:06.400 --> 1:44:11.000 biting mosquitoes. Attempting undercover pros use repellents to protect yourself 1:44:11.000 --> 1:44:13.599 and those that you love from the potential help gets 1:44:13.600 --> 1:44:15.960 of being bitten by a move who's heart a west 1:44:16.040 --> 1:44:18.839 Now virus. You may not real loize them. It's inside 1:44:18.840 --> 1:44:22.160 of mosquitoes and they get spreaddit to pieces, cover up rock, 1:44:22.240 --> 1:44:25.160 rebelling and ritt is standing water. Mosquito bites can mean 1:44:25.200 --> 1:44:27.960 more than just a vod yo who's herd a west 1:44:28.000 --> 1:44:30.799 Now virus. Cap may not realize them, but it's inside 1:44:30.840 --> 1:44:33.559 of mosquitoes and they get spread it to people, color 1:44:33.680 --> 1:44:36.840 up rock, repelling the GrITT is standing water. Mosquito bites 1:44:36.840 --> 1:44:40.000 can be more than just a bob west Now. There's 1:44:40.000 --> 1:44:42.599 arected public health in the summer time and here for 1:44:42.640 --> 1:44:45.800 twenty years shout out to Queen's ninety nine rapid spread 1:44:45.840 --> 1:44:48.759 from east to west. Now we're throughout the continental US 1:44:48.960 --> 1:44:52.599 qlex mosquito vector with the bird preference in nature, guests 1:44:52.600 --> 1:44:56.439 now cycles between mosquitoes and birds when those mosquitosquito people 1:44:56.520 --> 1:44:59.840 infections occur steady sipping dust till dawn because they're not 1:45:00.120 --> 1:45:03.439 time biders attack in twilight. Like micro vampire who's hurt 1:45:03.479 --> 1:45:06.479 a west Now virus may not realize them food it's 1:45:06.479 --> 1:45:09.080 inside of mosquitos and nicket spread it to people to 1:45:09.240 --> 1:45:12.840 color up rock repelling I finished standing water. Mosquito bites 1:45:12.840 --> 1:45:15.560 can be more than just a bottley who's hurt. A 1:45:15.640 --> 1:45:18.479 west Now virus can make a re alizza food. It's 1:45:18.479 --> 1:45:21.559 inside of mosquitoes and they get spreaded to people to cover. 1:45:21.640 --> 1:45:22.679 Up rock repelling. 1:45:22.720 --> 1:45:25.479 The frit is standing water, Mosquito bites can be boiled 1:45:25.640 --> 1:45:29.200 just a bottle now. Luckily, most folks effective will never 1:45:29.280 --> 1:45:32.919 feel sick, but somemost suffer from beaver rash, aches and weakness. 1:45:33.080 --> 1:45:36.439 The most recover completely. The fatigue can persists for weeks 1:45:36.520 --> 1:45:39.960 or months. You could be living lethargic and listless. Unfortunately, 1:45:40.080 --> 1:45:43.120 any age can get severe illness. Of people older than 1:45:43.160 --> 1:45:45.919 sixty and the sick of the highest risk of neuroin 1:45:46.000 --> 1:45:49.120 basic cases with lifelong effects except for light as men 1:45:49.200 --> 1:45:52.679 insitis from a virus that wrecks protect from west Now vibrus. 1:45:52.760 --> 1:45:56.040 Here's hoping you're realized side of mosquitoes and they get 1:45:56.040 --> 1:45:59.200 spreaded to people to cover up rock repelling. If frit 1:45:59.200 --> 1:46:01.720 is standing water, mosquito bites can be more than just 1:46:01.760 --> 1:46:09.479 a bomp. Just yourself representative control mosquito that never bites 1:46:09.520 --> 1:46:11.760 will never have the chance to change your life. Cover 1:46:11.880 --> 1:46:14.840 up and use EPA approved repellents. When mosquitoes are active, 1:46:14.920 --> 1:46:17.920 it's bugs in amount