WEBVTT - Ep 109 Chikungunya: Not dengue (or is it?) 0:00:02.000 --> 0:00:05.200 Towards the end of September eighteen twenty seven, a disease 0:00:05.280 --> 0:00:08.240 of a very singular character suddenly made its appearance in 0:00:08.280 --> 0:00:11.880 the island of Saint Thomas and attacked almost every individual 0:00:11.920 --> 0:00:14.800 in the town, which contains a population of about twelve 0:00:14.880 --> 0:00:19.040 thousand souls. The disease appeared so suddenly and spread with 0:00:19.160 --> 0:00:22.600 such rapidity, and the suffering attending it was so great 0:00:23.000 --> 0:00:25.799 that at first it caused universal alarm and was considered 0:00:25.800 --> 0:00:28.800 a sort of plague that would probably ravage the whole country. 0:00:29.600 --> 0:00:33.240 It was soon, however, discovered that although a very painful 0:00:33.560 --> 0:00:36.800 it was by no means a dangerous disease, and that 0:00:37.000 --> 0:00:40.840 if the attack was rapid, the recovery was no less speedy. This, 0:00:40.920 --> 0:00:44.440 at least was the general belief until longer experience showed 0:00:44.440 --> 0:00:47.760 the troublesome nature of the secondary pains that constitute the 0:00:47.800 --> 0:00:51.240 third stage of the disorder. The most usual mode of 0:00:51.280 --> 0:00:54.720 attack was the following. A person in perfect health would 0:00:54.760 --> 0:00:58.160 suddenly feel a stiffness amounting almost to a pain in 0:00:58.240 --> 0:01:02.040 one of his fingers, and frequently his little finger. The 0:01:02.080 --> 0:01:06.120 stiffness increased and was accompanied by an intense degree of pain, 0:01:06.440 --> 0:01:09.240 which spread rapidly over the whole hand and up the 0:01:09.400 --> 0:01:12.399 arm to the shoulder. The fingers of both hands in 0:01:12.440 --> 0:01:17.000 a few hours became swelled, stiff, and painful, preventing all 0:01:17.040 --> 0:01:20.280 attempts at bending the joints. This was followed in a 0:01:20.280 --> 0:01:23.720 short time by restlessness, depression of spirits, and a degree 0:01:23.760 --> 0:01:28.080 of nausea, ending in some cases in vomiting. Then came 0:01:28.120 --> 0:01:33.039 on shivering, succeeded by fever, great heat of skin, intense headache, 0:01:33.400 --> 0:01:37.319 most acute pain in the back, knees, ankles, and in 0:01:37.400 --> 0:01:41.240 short in every joint. But perhaps the most distressing symptom 0:01:41.280 --> 0:01:44.160 of this stage was the intense pain in the eyeballs. 0:01:44.920 --> 0:01:47.319 In every case where the first stage was in any 0:01:47.360 --> 0:01:51.000 degree well marked, patients declared that they had never experienced, 0:01:51.120 --> 0:01:53.919 nor could have conceived, pains equal to what they felt 0:01:54.080 --> 0:01:57.360 in this fever. Not one inch of the body from 0:01:57.440 --> 0:02:01.640 head to foot was exempt from suffering. An efflorescence was 0:02:01.680 --> 0:02:04.040 perceived at this time to begin at the palms of 0:02:04.080 --> 0:02:07.520 the hands and to spread over the whole body. After 0:02:07.600 --> 0:02:10.760 the aberuptive stage, the patient began to recover his spirits 0:02:10.840 --> 0:02:14.040 and his strength, but in many cases a complete want 0:02:14.040 --> 0:02:17.600 of taste remained for some days. Many people did not 0:02:17.600 --> 0:02:19.800 get rid of the pains in the joints for many weeks. 0:02:20.480 --> 0:02:23.440 In general, however, the disease gave a degree of respite 0:02:23.480 --> 0:02:26.560 for three, four and even in some cases six weeks, 0:02:27.000 --> 0:02:29.920 and then attacked the joints with more pain and paralysis 0:02:29.960 --> 0:02:32.960 than at first. I conclude with the hope that I 0:02:32.960 --> 0:02:35.680 have done my duty in endeavoring to record a disease 0:02:35.720 --> 0:02:39.560 attended with so many curious symptoms, as justly to challenge 0:02:39.560 --> 0:02:42.799 the attention of every medical man, and particularly of those 0:02:42.840 --> 0:03:32.160 who are destined to practice in tropical countries. I love 0:03:32.360 --> 0:03:35.600 these old timey descriptions, Aaron so much. 0:03:36.360 --> 0:03:39.640 I love that. So that was excerpted from this paper 0:03:40.200 --> 0:03:45.440 published in eighteen twenty eight by George Steadman. Yeah, titled 0:03:45.440 --> 0:03:48.240 some account of an anomalous disease which raged in the 0:03:48.280 --> 0:03:50.840 Islands of Saint Thomas and Santa Cruz in the West 0:03:50.920 --> 0:03:54.960 Indies during the months of September, October, November, December and 0:03:55.040 --> 0:03:57.440 January eighteen twenty seven to eighteen twenty eight. I guess 0:03:57.440 --> 0:03:59.760 they didn't have character limits and titles back then. 0:04:00.640 --> 0:04:03.240 The most descriptive and specific title. 0:04:04.840 --> 0:04:07.960 Yeah so that. Like that whole paper, which is available 0:04:08.040 --> 0:04:13.080 online is an interesting read. There's so much more detailed there, 0:04:13.120 --> 0:04:15.120 but I just pulled little excerpts that I thought were 0:04:15.160 --> 0:04:18.960 most descriptive of the topic of today's episode, which is 0:04:19.240 --> 0:04:24.240 chicken chicken virus. Hi, I'm erin Welsh. 0:04:23.760 --> 0:04:25.560 And I'm erin Almond Updike. 0:04:25.440 --> 0:04:27.799 And this is this podcast will kill You. 0:04:27.920 --> 0:04:32.080 Welcome to Is this our first mosquito born virus of 0:04:32.080 --> 0:04:33.000 our whole season? 0:04:34.680 --> 0:04:38.160 I think, so? Wow, I can't keep track anymore. 0:04:38.240 --> 0:04:40.520 Eric, I know same. I feel like we've done I mean, 0:04:40.560 --> 0:04:43.120 we've done like some lice and things. 0:04:43.520 --> 0:04:47.839 Yeah, we've done some vectors. Yeah, but yeah, mosquito born virus, 0:04:47.920 --> 0:04:48.440 I think. 0:04:48.480 --> 0:04:50.799 So. I'm excited. It's gonna be a good one. 0:04:51.240 --> 0:04:54.760 It is. I didn't really know anything about chicken gunya 0:04:54.800 --> 0:04:59.200 besides the name before getting into this, and yeah, I'm 0:04:59.480 --> 0:05:01.919 very curious to hear how the biology works. I know. 0:05:02.080 --> 0:05:05.159 I remember in twenty thirteen and twenty fourteen when the 0:05:05.160 --> 0:05:09.320 big outbreaks were happening in the Americas and being like, 0:05:09.480 --> 0:05:12.240 what's gonna happen with chicken gun yet? And then that 0:05:12.320 --> 0:05:14.560 was it. Yeah, And I never really learned much more 0:05:14.600 --> 0:05:16.240 about it, So it was it was fun to get 0:05:16.240 --> 0:05:19.839 to research. Yeah, but first, it's quarantiny time. 0:05:20.080 --> 0:05:22.800 It's quarantin any time. What are we drinking this week? 0:05:23.080 --> 0:05:28.240 We're drinking head, shoulders, knees and toes. 0:05:29.760 --> 0:05:33.080 Yeah, so we are drinking head, shoulders, knees and toes 0:05:33.920 --> 0:05:38.440 because one of the hallmark symptoms of chicken gunya virus, 0:05:38.440 --> 0:05:41.440 as you heard in our first hand account, is joint 0:05:41.440 --> 0:05:42.760 pain and headache. 0:05:43.000 --> 0:05:47.159 Yep, pretty pretty severe, as we'll discuss, very severe. 0:05:47.240 --> 0:05:50.960 Yeah. Yeah, So what is in head shoulders, knees and toes. 0:05:51.080 --> 0:05:54.599 Oh, it's a perfect little fall concoction. You've got some 0:05:54.760 --> 0:05:59.080 apple cider, some orange and some mez call for smokiness. 0:05:59.240 --> 0:06:02.159 Yeah. And also so as a callback to deng Gay, 0:06:02.440 --> 0:06:05.720 our dan Gay episode and our Dangae quarantini which had 0:06:05.800 --> 0:06:08.159 mes call in it. And because you're gonna hear a 0:06:08.160 --> 0:06:10.320 lot about dang Gay, I know there'll be. 0:06:10.279 --> 0:06:13.559 A lot of compare condrass, Dangay, chick Gunya, et cetera. 0:06:13.839 --> 0:06:15.720 So it makes sense, so we called back to it. 0:06:16.200 --> 0:06:21.160 We'll post the full recipe for our quarantine as well 0:06:21.200 --> 0:06:23.680 as our non alcoholic plausive to read it on our website. 0:06:23.680 --> 0:06:25.440 This podcast will tell you dot com and all of 0:06:25.480 --> 0:06:26.960 our social media channels. 0:06:26.880 --> 0:06:30.480 Before we dive into the episode. Of course, like the routine, 0:06:30.600 --> 0:06:32.920 check out our website, et cetera, et cetera. There's a 0:06:32.960 --> 0:06:36.599 lot of stuff there. But also, this is our second 0:06:36.640 --> 0:06:42.240 to last episode of season five. What Yeah, there's just 0:06:42.320 --> 0:06:44.800 one more coming out after this. But don't worry, we 0:06:44.839 --> 0:06:47.560 will be back. We're just gonna take a break and 0:06:48.320 --> 0:06:50.920 not read about disease stuff for a minute. 0:06:51.080 --> 0:06:53.320 I mean, we'll probably still read about disease stuff, but 0:06:53.440 --> 0:06:55.200 like just quietly to ourselves. 0:06:55.360 --> 0:07:00.400 Actually that's true, and then we'll just text each other exactly. Well, 0:07:00.440 --> 0:07:03.400 in any case, we will be back, and so make 0:07:03.440 --> 0:07:05.400 sure you follow us on all of our social media 0:07:05.400 --> 0:07:07.960 accounts so that you know when we are on our 0:07:08.000 --> 0:07:10.320 way back, and if you have suggestions that you really 0:07:10.360 --> 0:07:12.440 want to hear for next season, send them our way. 0:07:12.800 --> 0:07:17.200 Well with that, Aaron, shall we get into chicken gonavirus. 0:07:17.360 --> 0:07:45.800 Let's do it right after this break. Chicken gonavirus is 0:07:45.840 --> 0:07:50.440 an arbovirus, which means a virus transmitted by arthropod vectors. 0:07:50.480 --> 0:07:54.679 And in this case, like we said, mosquitoes, I'm probably 0:07:54.680 --> 0:07:58.040 gonna end up talking about the two main mosquito vectors 0:07:58.400 --> 0:08:00.880 more than anyone bargain for it's gonna be fun. 0:08:01.320 --> 0:08:03.960 I'm so glad because I did a little bit of 0:08:04.000 --> 0:08:06.320 diving into the ecology and I was like, I don't 0:08:06.320 --> 0:08:08.640 know where this goes in the history section. Hopefully erin 0:08:08.680 --> 0:08:09.680 we'll talk about it. 0:08:10.080 --> 0:08:12.360 Well. I found myself thinking so much of Ali and 0:08:12.440 --> 0:08:15.080 Allison in our old lab and being like, I wish 0:08:15.080 --> 0:08:16.920 I could call and be like, can you tell me 0:08:16.920 --> 0:08:21.600 about their ecology? Anyways, So let's get into it, shall we. 0:08:22.560 --> 0:08:25.920 Chicken gunia virus is in the genus alpha virus in 0:08:25.960 --> 0:08:30.440 the family Toga Virida, and these viruses there RNA viruses, 0:08:30.760 --> 0:08:35.120 the majority of which are arboviruses. They are transmitted by 0:08:35.280 --> 0:08:38.480 mosquitoes and other vectors. A few that people may have 0:08:38.600 --> 0:08:42.800 heard of include Ross River virus and Western and Eastern 0:08:42.880 --> 0:08:47.400 equine encephalitis viruses. One thing I thought was interesting about 0:08:47.440 --> 0:08:50.120 alpha viruses in general is that at least one of 0:08:50.160 --> 0:08:52.480 the papers that I was reading was talking about how 0:08:52.559 --> 0:08:56.400 for a lot of alpha viruses, humans and our domestic 0:08:56.440 --> 0:08:59.960 animals are often considered dead end hosts, so we aren't 0:09:00.120 --> 0:09:06.000 necessarily like the evolutionary hosts for these pathogens, which is 0:09:06.040 --> 0:09:09.440 I think very interesting, especially because I'm going to end 0:09:09.520 --> 0:09:13.479 up comparing and contrasting chicken guna virus in this episode, 0:09:13.800 --> 0:09:16.440 because it's compared a lot in the literature to a 0:09:16.520 --> 0:09:22.880 few other arboviruses like dengay zeca virus, yellow fever virus. 0:09:23.720 --> 0:09:27.240 All of those viruses are not in the alpha virus family. 0:09:27.360 --> 0:09:31.200 Those are all flaviaviruses, so a completely different family of viruses, 0:09:31.240 --> 0:09:34.439 some of which are very human specific like yellow fever 0:09:34.960 --> 0:09:38.439 or can cause disease in animals and humans kind of equally. 0:09:39.120 --> 0:09:41.840 That's interesting that humans are considered the dead end host 0:09:41.920 --> 0:09:46.880 for alpha viruses. Is that because of like viroemia and 0:09:47.120 --> 0:09:50.079 mosquitoes not being able to get enough virus or is 0:09:50.120 --> 0:09:53.120 it because mosquitoes aren't biting as much? Yeah? 0:09:53.160 --> 0:09:57.240 I think both from what I could tell. Okay, yeah, yeah, 0:09:57.440 --> 0:10:01.120 But as we'll see, that's not the case chicken gunyam. 0:10:03.440 --> 0:10:07.280 So the two major vector species of chicken gunya virus 0:10:07.480 --> 0:10:12.199 are mosquitoes that might be familiar to longtime listeners. They 0:10:12.200 --> 0:10:16.840 are mosquitoes in the genus eighties, particularly eighties albapictus and 0:10:16.960 --> 0:10:21.760 eighties agypdi. These are the same mosquitoes that are responsible 0:10:21.800 --> 0:10:25.840 for the transmission of dannge fever of yellow fever and 0:10:26.040 --> 0:10:29.880 of Zeca virus, among many others. There are a lot 0:10:29.880 --> 0:10:33.600 of other species of eighties mosquitoes that can also transmit 0:10:33.679 --> 0:10:36.920 chicken gunya as well as perhaps some species of Culex 0:10:36.960 --> 0:10:40.319 that have been found to be infected, but predominantly, especially 0:10:40.360 --> 0:10:44.760 for humans, it's Albapictus and Agypti, and that's probably how 0:10:44.800 --> 0:10:48.959 I'll refer to them throughout this episode. And like many 0:10:49.000 --> 0:10:53.720 of our mosquito born viral and other pathogens, this life 0:10:53.720 --> 0:10:56.719 cycle can be a little bit complicated, but it goes 0:10:56.760 --> 0:10:59.959 a little something like this. The mosquito takes the bite 0:11:00.080 --> 0:11:03.320 of an infected blood meal from an animal or a 0:11:03.400 --> 0:11:06.719 human in the case of chicken gunya, the virus has 0:11:06.800 --> 0:11:11.440 to travel through the guts of that mosquito, disseminate through 0:11:11.520 --> 0:11:15.839 the gut wall of the mosquito, travel through the hemolymph, 0:11:16.160 --> 0:11:21.040 and invade the salivary glands where they can replicate. And 0:11:21.160 --> 0:11:26.200 this process for chicken gunya virus within the mosquito takes 0:11:26.240 --> 0:11:31.360 between two and five days to happen. Okay, So what 0:11:31.440 --> 0:11:34.120 that means is that the adult mosquito, after it takes 0:11:34.160 --> 0:11:36.920 its first blood meal, has to live at least two 0:11:36.960 --> 0:11:40.520 to five days to then be infectious to another person. 0:11:41.120 --> 0:11:44.040 I have a question about mosquito longevity. 0:11:44.200 --> 0:11:47.240 Ooh, kyote, so glad Eron has so many fun facts 0:11:47.280 --> 0:11:48.239 about these mosquitoes. 0:11:48.520 --> 0:11:52.760 Yes, okay, excellent. How long on average do the different 0:11:52.800 --> 0:11:55.400 species Albapictus and Egypti live? 0:11:55.640 --> 0:11:59.719 So these mosquitoes take about a week to develop from 0:11:59.760 --> 0:12:03.160 an egg into adult, but once they are adults, they 0:12:03.160 --> 0:12:06.760 can live for four to six weeks okay mm hm, 0:12:07.040 --> 0:12:07.480 which is. 0:12:07.440 --> 0:12:09.760 A lot of very long biting potential. 0:12:10.160 --> 0:12:13.880 It sure is, and it's only female mosquitoes that bite. 0:12:14.000 --> 0:12:16.120 They have to take a blood meal in order to 0:12:16.320 --> 0:12:20.400 make eggs in order to lay a brood, and eighties 0:12:20.480 --> 0:12:24.560 mosquitoes if they are able to take an entire blood meal, 0:12:24.600 --> 0:12:27.520 and there are differences between eighties agypdi and Albapictus in 0:12:27.600 --> 0:12:30.360 terms of like how often they lay eggs and things 0:12:30.440 --> 0:12:33.920 like that, but if they took a whole entire blood meal, 0:12:34.000 --> 0:12:36.800 they might be able to go several days between feedings. 0:12:37.280 --> 0:12:40.440 But what often happens is that they get interrupted really 0:12:40.480 --> 0:12:43.680 frequently during their feedings, so they don't get a whole 0:12:43.679 --> 0:12:46.960 blood meal at once, so they might bite and then bite, 0:12:47.080 --> 0:12:49.960 and then bite and then bite in order to get 0:12:50.040 --> 0:12:52.360 enough blood to be able to make an egg brood. 0:12:53.320 --> 0:12:56.720 So it's not like one blood meal or one feeding 0:12:56.800 --> 0:13:01.160 sash one infected person. It could be five feeding sesshes 0:13:01.280 --> 0:13:05.199 to get your you know, stomach full, and you infect 0:13:05.200 --> 0:13:08.880 five people. So is it there? Yeah, like viral load, 0:13:09.160 --> 0:13:12.400 infectious dose, like you know, does that play a role 0:13:12.440 --> 0:13:13.080 in it as well? 0:13:13.600 --> 0:13:16.640 Great question. I totally don't have answers for you on that, 0:13:17.160 --> 0:13:19.880 Like how many viral particles does a mosquito have in 0:13:19.920 --> 0:13:22.640 their salvary glands and how many are they injecting with 0:13:22.679 --> 0:13:26.160 aged feed? I have no idea, but at least in theory, 0:13:26.360 --> 0:13:29.800 if this mosquito is biting many different hosts, not only 0:13:29.880 --> 0:13:33.040 is that many opportunities to become infected, but it's also 0:13:33.160 --> 0:13:35.360 many opportunities to transmit that pathogen. 0:13:35.760 --> 0:13:39.240 Makes sense and wow, But going back. 0:13:39.120 --> 0:13:42.320 To the timeline of it, so two to five days 0:13:42.400 --> 0:13:45.319 for that process of dissemination through the guts before a 0:13:45.360 --> 0:13:49.960 mosquito becomes infectious. Here we start to compare contrast something 0:13:50.000 --> 0:13:53.280 like chicken gunya with something like dan gay virus. Dingay 0:13:53.400 --> 0:13:57.200 virus takes eight to ten days before it's transmissible in 0:13:57.280 --> 0:14:01.480 the adult mosquito. So all, you have a mosquito that 0:14:01.520 --> 0:14:04.719 doesn't have to live nearly as long before it can 0:14:04.760 --> 0:14:07.040 start infecting other people. 0:14:07.760 --> 0:14:10.040 Interesting, So I guess that would probably play a big 0:14:10.120 --> 0:14:13.440 role in how fast an epidemic or an outbreak happens. 0:14:13.920 --> 0:14:17.760 Sure could mm hmm. All right, So continuing on in 0:14:17.800 --> 0:14:22.200 our life cycle, once that mosquito is infectious, it takes 0:14:22.240 --> 0:14:25.560 another blood meal, and then those viruses are injected from 0:14:25.560 --> 0:14:29.920 the salivary glands into our subcutaneous tissues. Those viruses make 0:14:29.960 --> 0:14:33.240 their way into our bloodstream, they infect a number of 0:14:33.320 --> 0:14:38.040 different cells. They infect our fibroblast cells, they can replicate 0:14:38.080 --> 0:14:40.960 in our skin cells. They make their way into our 0:14:41.000 --> 0:14:43.920 liver and into our joints, where they infect a variety 0:14:44.080 --> 0:14:47.760 of cells. I'm going to pause in the life cycle 0:14:47.800 --> 0:14:50.800 here because i want to talk a little bit more 0:14:50.880 --> 0:14:54.680 about these two species of mosquito, even though we've already 0:14:54.760 --> 0:14:56.840 kind of like dove into some of the fun bits. 0:14:58.200 --> 0:15:02.600 These two species of mosquito, eighties albapictus and eighties agypti. 0:15:02.960 --> 0:15:05.440 We've talked about them a lot because we've done zeca, 0:15:05.480 --> 0:15:10.040 we've done yellow fever, we've done dengey. These mosquitoes are 0:15:10.160 --> 0:15:17.880 particularly good particularly well adapted to rural, urban, and human 0:15:18.120 --> 0:15:23.360 built environments, especially eighties agypti. This is a mosquito that 0:15:23.520 --> 0:15:29.560 like just loves humans and our urban environments. These two 0:15:29.600 --> 0:15:34.200 mosquito species are generally both container breeding mosquitoes, so they 0:15:34.200 --> 0:15:38.200 do really well in things like old tires or that 0:15:38.320 --> 0:15:41.400 pot you forgot about that one pothole in your street 0:15:41.400 --> 0:15:44.920 that absolutely never drains your neighbor's pool that they drained 0:15:44.960 --> 0:15:46.920 three years ago but they never filled it, so there's 0:15:46.960 --> 0:15:50.480 just like an inch of water in there. Also tree 0:15:50.560 --> 0:15:55.320 holes in more like suburban or rural environments, et cetera. 0:15:55.680 --> 0:15:59.760 Any tiny amount of standing water is enough for eighties 0:15:59.800 --> 0:16:02.760 and hype and Albapictus both to be able to breed 0:16:02.960 --> 0:16:11.120 and survive. These two mosquitoes are also very aggressive. They're 0:16:11.440 --> 0:16:16.320 really aggressive biters, especially for humans, like they really like humans, 0:16:17.120 --> 0:16:21.480 and especially eighties Albapictus tend to be more diurnal than 0:16:21.520 --> 0:16:25.080 most mosquito species, so they can primarily bite during the daytime, 0:16:25.200 --> 0:16:28.160 in the mornings and in the evenings, so they're really 0:16:28.240 --> 0:16:32.120 difficult to avoid, and things like bednets that are often 0:16:32.240 --> 0:16:35.200 used to protect against other mosquito species that bite at 0:16:35.280 --> 0:16:38.120 night don't do anything to prevent the bites of eighties 0:16:38.160 --> 0:16:42.120 albapictus and eighties agypty right, And like I said, they 0:16:42.120 --> 0:16:45.360 can complete their entire initial life cycle in as little 0:16:45.400 --> 0:16:47.880 as a week from egg all the way to adult. 0:16:48.360 --> 0:16:52.280 So in times of plenty in terms of rainfall, like 0:16:52.320 --> 0:16:56.360 the rainy season, you have many many broods of mosquitoes 0:16:56.600 --> 0:16:59.280 over and over hatching and going out in search of 0:16:59.320 --> 0:17:02.640 new blood meal. But at the same time, like many 0:17:02.680 --> 0:17:06.520 mosquito species, these eggs can dry out completely and then 0:17:06.600 --> 0:17:09.760 survive until the next rainfall season. That's why they can 0:17:09.760 --> 0:17:12.560 do so well. In these small containers of water that 0:17:12.640 --> 0:17:15.439 might dry out completely, they can just hang on. 0:17:16.000 --> 0:17:20.840 It's amazing and I respect it, but I also hate it. 0:17:21.640 --> 0:17:26.520 I know, I know, I know. So that's just kind 0:17:26.520 --> 0:17:31.200 of some fun facts about eighties agypti and Albapictus. I'll 0:17:31.200 --> 0:17:33.879 probably talk more about them in the current event section 0:17:33.960 --> 0:17:41.840 because they're also really important invasive species worldwide, especially eighties albapictus. Yeah, so, 0:17:42.640 --> 0:17:46.000 and they spread so many different diseases that they're an 0:17:46.000 --> 0:17:50.840 incredibly important source of vector born disease. But if that 0:17:51.040 --> 0:17:55.720 isn't enough, chicken gunya virus can also be spread via 0:17:55.840 --> 0:17:59.320 vertical transmission within the mosquito, meaning it can pass into 0:17:59.359 --> 0:18:02.960 the eggs and result in larvae and therefore adults that 0:18:03.000 --> 0:18:04.480 are already infected. 0:18:04.760 --> 0:18:06.640 It's horrible. It's terrible. 0:18:06.760 --> 0:18:09.560 I didn't I don't know the rate at which this happens, 0:18:11.000 --> 0:18:16.480 but it definitely happens. And just to make it even worse, 0:18:17.720 --> 0:18:22.480 males who become infected at birth. Males do not blood feed, 0:18:22.640 --> 0:18:25.120 so they can't become infected as adults, but they can 0:18:25.160 --> 0:18:30.680 be born infected and can infect females during the mating process. 0:18:31.520 --> 0:18:35.320 So this virus is just really good at spreading through 0:18:35.359 --> 0:18:36.199 these mosquitoes. 0:18:37.000 --> 0:18:41.320 And that's just for eighties Egypti. Right, the vertical transmission. 0:18:41.000 --> 0:18:44.000 I saw it primarily for eighties EGYPTI. 0:18:44.520 --> 0:18:47.280 Okay, Yeah, And like I. 0:18:47.240 --> 0:18:51.320 Said, chicken gunya virus is more than just a human virus. 0:18:51.400 --> 0:18:54.760 So these mosquitoes can become infected by biting a huge 0:18:54.880 --> 0:18:58.919 variety of mammals, including rodents, bats, non human primates, but 0:18:59.040 --> 0:19:02.399 also even birds and reptiles that can become infected and 0:19:02.480 --> 0:19:06.560 harbor chicken gunea virus. I didn't get a sense. And 0:19:06.640 --> 0:19:12.640 I think that because this disease has largely been an 0:19:12.800 --> 0:19:17.960 outbreak disease. The outbreak patterns in humans tend to be 0:19:18.040 --> 0:19:21.760 from human to vector to human transmission, so like humans 0:19:21.760 --> 0:19:25.320 being the primary reservoir, largely because these two species of 0:19:25.359 --> 0:19:28.680 mosquitoes do really like to bite humans. So I didn't 0:19:28.680 --> 0:19:32.040 get a sense of what the natural reservoirs likely are 0:19:32.600 --> 0:19:35.240 across the globe, but it probably varies in different parts 0:19:35.280 --> 0:19:35.800 of the world. 0:19:36.040 --> 0:19:39.080 Yeah, it seems like historically they found it in non 0:19:39.160 --> 0:19:41.719 human primates, and then the more sampling they did, the 0:19:41.720 --> 0:19:45.880 more they found in other species, as as tense often happens. 0:19:46.119 --> 0:19:50.399 Yeah, so all of that is just the virus, the 0:19:50.480 --> 0:19:55.040 mosquitoes and the transmission. Let's get into the disease that 0:19:55.200 --> 0:19:56.879 chicken gunya causes, shall we. 0:19:57.440 --> 0:19:58.000 Let's do it. 0:19:59.080 --> 0:20:04.440 So, once a person gets bitten and this mosquito injects 0:20:04.480 --> 0:20:08.119 you full of virus, the incubation period tends to be 0:20:08.320 --> 0:20:13.120 about two to four days. Different papers report slightly different ranges, 0:20:13.200 --> 0:20:15.639 but that's about the average. 0:20:15.960 --> 0:20:18.480 I feel like that's a pretty tight range. It is. 0:20:18.600 --> 0:20:20.680 I mean, it does range from like one to twelve, 0:20:20.760 --> 0:20:21.520 but I think. 0:20:21.680 --> 0:20:24.440 Okay, never mind, I take it back. 0:20:24.560 --> 0:20:27.440 I know, I know, but in general, like most papers 0:20:27.560 --> 0:20:30.520 consensus two to four. Some like to say three to 0:20:30.600 --> 0:20:34.840 seven just to hedge their bets. Okay, but symptom onset 0:20:34.960 --> 0:20:39.640 tends to be abrupt and severe. The first hand account 0:20:39.680 --> 0:20:43.399 that we read was actually a pretty decent description of 0:20:43.440 --> 0:20:46.080 what I'm about to talk about, especially when you consider 0:20:46.080 --> 0:20:50.240 those from the eighteen hundreds. So love that the symptoms 0:20:50.280 --> 0:20:56.960 tend to start with a fever, of course, headache, back pain, 0:20:57.840 --> 0:21:03.960 very very severe joint pain and in potentially any joint ankles, wrist, fingers, hips, knees, 0:21:04.240 --> 0:21:08.360 large joints, small joints, and it does tend to be 0:21:08.520 --> 0:21:12.320 like so severe that it is difficult to bear. And 0:21:12.400 --> 0:21:16.320 people often will have like rigers and be bent over 0:21:16.480 --> 0:21:21.360 and just in an excruciating amount of pain. About fifty 0:21:21.400 --> 0:21:25.840 percent of people ish will also have some kind of 0:21:25.880 --> 0:21:30.320 skin involvement. The most common rash is a very itchy, 0:21:31.240 --> 0:21:34.199 red splotchy kind of what I think of is just 0:21:34.240 --> 0:21:38.040 a very generic viral looking rash, so like little red 0:21:38.080 --> 0:21:41.280 splotches with bumps in the middle, what we call maculo popular. 0:21:42.000 --> 0:21:44.920 And this can be across the chest, the stomach, the back. 0:21:45.440 --> 0:21:47.600 I know the first hand account mentioned the palms, but 0:21:47.680 --> 0:21:50.120 I don't think that we tend to see that very commonly. 0:21:51.040 --> 0:21:54.960 What's interesting is that in children the rash can often 0:21:55.040 --> 0:21:59.119 be quite different, with more of a blistering appearance, like 0:21:59.320 --> 0:22:04.720 very large blisters across the whole skin, or even with petikia, 0:22:04.920 --> 0:22:07.679 which are those tiny little purple spots that mean that 0:22:07.720 --> 0:22:10.920 you're having little, tiny pinpoint bleeds underneath your skin. 0:22:11.600 --> 0:22:14.560 Why is it different? Just immune system stuff? 0:22:14.720 --> 0:22:23.440 Yeah, great question, no clue. And in general, chicken gunya 0:22:23.720 --> 0:22:29.320 fever tends to be considered a self limited condition. Usually 0:22:29.560 --> 0:22:33.320 these symptoms are going to resolve in seven to ten days, 0:22:33.800 --> 0:22:38.160 which is a long time to be this sick. However, 0:22:38.680 --> 0:22:44.960 this incredibly painful arthritis can in some cases persist for 0:22:45.160 --> 0:22:47.920 months or even years afterwards. 0:22:48.320 --> 0:22:49.520 Oh my gosh. 0:22:49.840 --> 0:22:53.280 Yeah, it's horrible. And what's truly awful is that this 0:22:53.359 --> 0:22:56.800 happens in up to thirty to forty percent of people 0:22:56.880 --> 0:22:58.840 who are infected with chicken gunyavirus. 0:22:59.119 --> 0:22:59.359 Wow. 0:23:00.040 --> 0:23:04.400 Huge number. We don't know exactly what causes this chronic 0:23:04.560 --> 0:23:08.520 joint pain, this chronic arthritis, but so far it's not 0:23:08.640 --> 0:23:13.280 thought to be due to chronic infection. Okay, because in general, 0:23:13.400 --> 0:23:16.160 when we've tried to study it, people have not been 0:23:16.200 --> 0:23:20.080 able to isolate virus from the joint fluid of people 0:23:20.160 --> 0:23:23.480 with this chronic arthritis as a result of chicken gunya. 0:23:24.160 --> 0:23:27.159 So it's thought to likely be something that's immune mediated, 0:23:27.240 --> 0:23:30.560 which is something that we see with other rboviral, viral 0:23:30.680 --> 0:23:34.040 and bacterial infections as well, and one of those things 0:23:34.040 --> 0:23:36.879 that we still just don't really understand. 0:23:36.920 --> 0:23:39.720 What causes the acute joint pain. 0:23:40.359 --> 0:23:43.840 Oh great question. Arin to say that we don't really 0:23:43.920 --> 0:23:47.359 understand the path of physiology of chicken gunya virus, I 0:23:47.359 --> 0:23:50.439 think is an understatement and I always say that we 0:23:50.480 --> 0:23:56.800 don't understand things. In small animal studies, we see that 0:23:56.840 --> 0:24:00.760 it's primarily muscular skeletal tissues that are in infected by 0:24:00.800 --> 0:24:07.560 this virus, especially muscles surrounding joints as well as skin fibroblasts. 0:24:07.600 --> 0:24:10.640 Fibroblasts are this like generic cell type that are involved 0:24:10.680 --> 0:24:14.280 in connective tissue formation. And so since this is a 0:24:14.320 --> 0:24:17.240 virus that has to infect our cells in order to replicate, 0:24:17.600 --> 0:24:20.959 these are the cell types, these fibroblasts and these muscle 0:24:21.000 --> 0:24:26.160 cells that they tend to infect and replicate in. There 0:24:26.280 --> 0:24:30.600 is some evidence from these again animal studies, that mice 0:24:30.760 --> 0:24:34.800 who lack T cells, especially certain subsets of T cells, 0:24:35.160 --> 0:24:38.879 have much less severe joint swelling and tissue damage as 0:24:38.920 --> 0:24:42.080 a result of this viral infection. So it's thought that 0:24:42.160 --> 0:24:44.800 perhaps it's at least in part a T cell mediated 0:24:44.880 --> 0:24:47.960 response that causes all of this joint pain and inflammation 0:24:48.840 --> 0:24:53.640 in those spaces, because that's where the virus is actually infecting. 0:24:53.640 --> 0:24:57.200 And that's like the muscle, there's like muscle involvement. 0:24:57.480 --> 0:25:00.119 It can infect muscle cells. It doesn't mean that the 0:25:00.160 --> 0:25:03.040 inflammation will be in the muscles necessarily, but there's also 0:25:03.160 --> 0:25:06.840 often a lot of muscle pain with chaspana as well. 0:25:06.920 --> 0:25:10.639 So this only because we've just covered gout. How does 0:25:11.200 --> 0:25:16.160 how does this joint pain differ from gout joint pain? 0:25:16.480 --> 0:25:19.480 What a fun question. So gout tends to be a 0:25:19.640 --> 0:25:23.160 very one joint at a time or a few joints 0:25:23.160 --> 0:25:25.919 at a time. This is every joint in your body. 0:25:26.280 --> 0:25:29.000 There's similarities in that in both of them, a lot 0:25:29.040 --> 0:25:32.119 of the pain is going to be driven by the inflammation, 0:25:32.680 --> 0:25:36.120 which is driven by our immune response to some kind 0:25:36.160 --> 0:25:40.399