WEBVTT - Ep 140 Nipah virus: Of Fruit and Bats 0:00:00.280 --> 0:00:04.160 I was so overcome by sadness that as soon as 0:00:04.160 --> 0:00:09.120 we completed capturing the required electron micrograph images, I requested 0:00:09.160 --> 0:00:12.319 doctor Crop to use the phone in CDC and called 0:00:12.360 --> 0:00:15.360 up my head in Malaysia. I managed to get him 0:00:15.360 --> 0:00:19.239 at home. I still remember vividly what I told him 0:00:19.280 --> 0:00:23.880 over the phone. Professor lamb Tua hear calling from CDC 0:00:24.040 --> 0:00:28.800 for Collins. Professor listen, listen carefully under the electron microscope. 0:00:28.840 --> 0:00:33.280 The virus has the morphology of a paramixavirus. For God's sake, 0:00:33.400 --> 0:00:37.640 please do not talk about Japanese encephalitis anymore. I'm quite 0:00:37.680 --> 0:00:41.159 sure now it's a paramixavirus. Most likely it is a 0:00:41.200 --> 0:00:45.839 new paramixavirus. The control measures for paramixavirus are totally different 0:00:45.880 --> 0:00:49.199 from Japanese and cephalitis virus. Please, I want you to 0:00:49.360 --> 0:00:52.360 urgently pass this message to the Ministry of Health to 0:00:52.440 --> 0:00:56.360 stop all the Japanese encephalitis control measures and switch over 0:00:56.400 --> 0:01:00.480 to the following control measures. Professor listen carefully. You must 0:01:00.520 --> 0:01:02.880 pass the information of what I have just said to 0:01:02.920 --> 0:01:06.360 the Ministry of Health as soon as possible. I'll get 0:01:06.360 --> 0:01:09.240 doctor Bruce Crop to process the electron micross could be 0:01:09.280 --> 0:01:11.399 photographed and fax it to you as soon as it 0:01:11.440 --> 0:01:15.880 is ready. There was a fairly long silence and he 0:01:15.920 --> 0:01:17.440 did not reply to my words. 0:02:03.760 --> 0:02:05.360 Wow, Aaron, Wow. 0:02:06.160 --> 0:02:12.079 Yeah. So that was from a paper titled the Discovery 0:02:12.120 --> 0:02:16.680 of Nepavirus, a personal account, written of course by Chua 0:02:16.960 --> 0:02:21.880 Copping doctor Chua, who, well you'll hear later from him 0:02:21.960 --> 0:02:24.600 more in the episode, played a really pivotal role in 0:02:24.639 --> 0:02:30.160 the discovery of nepovirus. And I just like this paper. 0:02:30.680 --> 0:02:34.760 It's a personal account of his experience. It's amazing and 0:02:34.800 --> 0:02:37.040 so like, this is just a small little excerpt from it, 0:02:37.400 --> 0:02:40.720 but really the whole thing is so invaluable because I 0:02:40.720 --> 0:02:43.200 think it shows what was he feeling, what was he 0:02:43.320 --> 0:02:45.799 thinking every sort of step of the way, what was 0:02:45.840 --> 0:02:49.480 it like to be there? And we don't really get 0:02:49.520 --> 0:02:50.480 that very much. 0:02:50.960 --> 0:02:53.920 Yeah, to like understand from a first person account of 0:02:53.960 --> 0:02:58.200 someone who was actively working on this during this outbreak, 0:02:58.480 --> 0:03:00.919 on this infection, trying to help trying to figure out 0:03:00.960 --> 0:03:04.520 what was going on, Like, Yeah, what did that feel like? 0:03:04.560 --> 0:03:06.919 What was that like? We don't get to see that 0:03:07.080 --> 0:03:07.880 very much anymore. 0:03:08.160 --> 0:03:10.880 We don't, And that's why I just I love it. 0:03:11.280 --> 0:03:13.160 Go read it. Hi. 0:03:13.639 --> 0:03:16.679 I'm Aaron Welsh and I'm Erin Alman Upday. 0:03:16.680 --> 0:03:18.880 And this is this podcast will kill You. 0:03:19.480 --> 0:03:21.200 Welcome to today's episode. 0:03:21.240 --> 0:03:26.079 Today to today's episode today on Nepa virus. 0:03:26.560 --> 0:03:27.480 Nepa virus. 0:03:27.600 --> 0:03:30.639 Yeah, at least a few of you have suggested this. 0:03:31.120 --> 0:03:33.520 It's been on our list for a really long time, 0:03:33.639 --> 0:03:36.560 and it's been It's been really interesting to kind of 0:03:36.680 --> 0:03:40.640 finally dig into Like I knew what it was, I'm like, oh, yeah, okay, 0:03:40.720 --> 0:03:45.720 this really deadly virus spillover, et cetera. That's whatever. But 0:03:45.800 --> 0:03:50.680 then to actually read about it, I'm like, oh, all right, Yeah. 0:03:50.400 --> 0:03:52.640 To actually get to spend the time to dig into it, 0:03:52.600 --> 0:03:54.920 It's it's going to be a great episode. I'm super excited. 0:03:55.200 --> 0:03:58.200 It's going to be a great episode. Also because we 0:03:58.640 --> 0:04:02.440 are going to be chatting with an expert guest later 0:04:02.560 --> 0:04:03.480 in the episode. 0:04:03.720 --> 0:04:07.120 Our favorite thing to do, Kearn's gone to get this season, 0:04:07.200 --> 0:04:08.120 I know, I know. 0:04:08.360 --> 0:04:12.240 And also we're gonna ask them to pick up the 0:04:12.320 --> 0:04:14.840 slack that we will be dropping when it comes to 0:04:14.960 --> 0:04:20.200 talking about the ecological factors that contribute to outbreaks of nepavirus. 0:04:20.320 --> 0:04:23.920 So doctor Cliff McKee, who is a research associate at 0:04:23.960 --> 0:04:27.040 Johns Hopkins Bloomberg School of Public Health will be joining 0:04:27.120 --> 0:04:30.640 us to talk about the dynamics of pathogen spillover events 0:04:30.640 --> 0:04:35.640 from bats to humans. So excited, So excited? I wait, 0:04:36.200 --> 0:04:38.160 me too, But we have a lot to cover before 0:04:38.200 --> 0:04:44.080 we get there, including it's quarantine eytime. What are we 0:04:44.160 --> 0:04:45.159 drinking this week? 0:04:45.600 --> 0:04:49.120 We're drinking when pigs fly, which will make sense. It'll 0:04:49.120 --> 0:04:51.080 make sense later in the episode. It will, it will, 0:04:51.120 --> 0:04:53.680 it will. It's you know, bats, pigs whatever. 0:04:53.920 --> 0:04:57.520 We'll get there, and the quarantining itself is quite a 0:04:57.560 --> 0:05:01.880 delicious one. It has rum, it has mangos, it has lime, 0:05:02.560 --> 0:05:05.440 passion fruit. You know, it's tasty, and we will post 0:05:05.480 --> 0:05:08.720 the full recipe on our website. 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Let's get started, Aaron, Okay, right after this break. 0:06:54.600 --> 0:06:58.600 So, NEPA virus is an RNA virus in the family 0:06:58.960 --> 0:07:02.720 paramix of your which a longtime fans of the pod 0:07:03.120 --> 0:07:06.520 might be familiar with, because we've actually covered some other 0:07:06.600 --> 0:07:10.640 PARAMIXA viruses on this podcast before Measles is a paramix 0:07:10.640 --> 0:07:13.960 of virus, mumps is a paramix of virus. Other ones 0:07:14.000 --> 0:07:16.760 you might have heard of include the para influenza viruses, 0:07:16.800 --> 0:07:20.240 which cause common colds. Can't forget about Render. 0:07:19.920 --> 0:07:22.720 Pests, Render Pest one of I think one of my 0:07:22.720 --> 0:07:26.400 favorite episodes. A great success story when it comes to 0:07:27.080 --> 0:07:32.520 public health or wildlife health, or veterinary health, One Health Health, 0:07:32.880 --> 0:07:36.040 One Health. That's the thing, One Health. 0:07:37.680 --> 0:07:40.760 Also, Hendra virus, which we have not yet covered but 0:07:40.800 --> 0:07:44.920 we will someday, is the most closely related to NPA virus. 0:07:45.400 --> 0:07:48.600 So nepa virus and hendravirus are both in the family 0:07:48.720 --> 0:07:51.680 paramix of Iriday and the genus they kind of have 0:07:51.760 --> 0:07:54.960 their own, which is called henipa virus. I think it's 0:07:54.960 --> 0:08:01.440 a combination of hendra and NPA virus. It stands creative. Now. 0:08:01.720 --> 0:08:04.160 I don't want to bury the lead here too much 0:08:04.520 --> 0:08:08.200 for anyone who didn't request nepavirus, who's maybe never heard 0:08:08.200 --> 0:08:10.120 of this thing and is wondering why the heck we're 0:08:10.160 --> 0:08:14.520 covering this virus that they've never heard of. Nepovirus has 0:08:14.560 --> 0:08:18.320 been named one of the top ten highest priority pathogens 0:08:18.480 --> 0:08:21.120 for the World Health Organization to focus on in terms 0:08:21.160 --> 0:08:24.600 of the development of countermeasures. That means focus on vaccines, 0:08:24.680 --> 0:08:28.760 focus on developing treatments, focus on prevention. And the reason 0:08:28.840 --> 0:08:35.040 is because NEPA virus has huge pandemic potential, so not 0:08:35.120 --> 0:08:37.280 to jump ahead too much. But not only is this 0:08:37.400 --> 0:08:41.880 virus capable of spreading person to person, not only has 0:08:41.920 --> 0:08:44.840 it continued to pop up and spread to new places 0:08:44.920 --> 0:08:48.160 year after year, as we'll talk about, but Nepa virus 0:08:48.280 --> 0:08:52.240 is also one of the most fatal infections that we've 0:08:52.280 --> 0:08:56.480 seen in humans. Case fatality rates on the low end 0:08:57.000 --> 0:09:00.600 tend to be around at least forty percent, and in 0:09:00.679 --> 0:09:04.280 many outbreaks they've been upwards of ninety percent of cases. 0:09:04.720 --> 0:09:05.600 It is unreal. 0:09:06.240 --> 0:09:11.480 It is terrifying in all honesty. Yeah, yeah, So it's 0:09:11.520 --> 0:09:13.960 a big deal virus and you're gonna learn all about 0:09:13.960 --> 0:09:19.880 it today. So NPA virus primary reservoir is bats, so 0:09:20.960 --> 0:09:25.079 in nature, in the wild, it lives specifically in bats 0:09:25.080 --> 0:09:30.160 in the genus Teropis terrapus terrapus. I think I decided 0:09:30.160 --> 0:09:30.840 it's terrapists. 0:09:31.360 --> 0:09:34.200 We had a conversation about this, and I have forgotten 0:09:34.320 --> 0:09:35.360 what we landed on. 0:09:35.840 --> 0:09:38.480 I looked it up several times and then I pronounced 0:09:38.480 --> 0:09:40.840 it wrong the first time. I just said it it's terrapists. 0:09:42.000 --> 0:09:46.080 These are flying foxes, fruit bats. Right, There's a few 0:09:46.080 --> 0:09:49.439 different species, but for much of the distribution of NEPA 0:09:49.520 --> 0:09:54.280 virus that we've studied so far, it's predominantly Terrapus medius 0:09:54.320 --> 0:09:59.480 that's been implicated in NPA transmission thus far, and NEPA 0:09:59.600 --> 0:10:03.560 has outbreaks in humans in a number of different countries 0:10:03.600 --> 0:10:09.359 across South and Southeastern Asia and the Pacific, including India, Malaysia, Singapore, 0:10:09.440 --> 0:10:13.800 the Philippines, and Bangladesh. But the bats that carry these 0:10:13.880 --> 0:10:19.280 viruses are distributed really widely across Asia, the Pacific, Australia, 0:10:19.360 --> 0:10:24.280 even parts of Africa. The majority of cases thus far, 0:10:24.720 --> 0:10:29.480 like by far, have occurred as the result of spillover events, 0:10:29.600 --> 0:10:34.120 So this is a zoonotic disease primarily, and most of 0:10:34.120 --> 0:10:38.079 the spillover events have happened either from bats to humans 0:10:38.440 --> 0:10:43.319 like a little bit directly, or from bats to domestic animals, 0:10:43.480 --> 0:10:48.400 especially pigs, and then to humans. But like I mentioned, 0:10:48.440 --> 0:10:51.880 this virus has also shown that it is entirely capable 0:10:51.920 --> 0:10:55.480 of being transmitted person to person as well. So let's 0:10:55.520 --> 0:10:57.840 get into a little bit more detail about how this 0:10:58.000 --> 0:11:02.640 virus makes its way into humans. What's interesting is that 0:11:02.840 --> 0:11:06.360 so far in different geographic areas where we have seen NIPA, 0:11:07.080 --> 0:11:10.199 there seems to be different modes of transmission that kind 0:11:10.200 --> 0:11:13.920 of predominate. And maybe we'll ask doctor McKee a little 0:11:13.920 --> 0:11:16.840 bit more detail about the ecology of this. And it 0:11:16.880 --> 0:11:19.080 also might have to do with the viral strains, because 0:11:19.080 --> 0:11:24.240 there's two different major viral strains in Malaysia where NEPA 0:11:24.360 --> 0:11:26.120 was first detected. And I know you're going to talk 0:11:26.160 --> 0:11:26.600 all about it. 0:11:26.720 --> 0:11:27.839 How dare you? 0:11:29.920 --> 0:11:32.760 How dare I mention that this was first detected at 0:11:32.760 --> 0:11:33.560 some point in time? 0:11:33.840 --> 0:11:36.880 Why do I even do anything on this podcast? I 0:11:37.040 --> 0:11:37.560 just kidding. 0:11:39.320 --> 0:11:42.200 So in Malaysia, where it was first detected, outbreaks have 0:11:42.240 --> 0:11:47.440 been associated with contact specifically with intermediate hosts, mostly pigs, 0:11:47.760 --> 0:11:50.800 and it's thought that these pigs got infected by eating 0:11:50.960 --> 0:11:54.720 fruit that was mostly bitten or possibly poopter peed on 0:11:54.960 --> 0:11:59.400 by bats, and then humans got infected via direct contact 0:11:59.440 --> 0:12:03.440 with those domestic animals, either through things like slaughterhousework or 0:12:03.480 --> 0:12:08.640 farm work, or through even contaminated meat. Then in the 0:12:08.679 --> 0:12:11.960 Philippines we have seen outbreaks that have been associated also 0:12:12.040 --> 0:12:16.120 with an intermediate host between bats and humans, but there 0:12:16.200 --> 0:12:19.160 it seems to be horses and horse meat that has 0:12:19.200 --> 0:12:24.040 been involved. And then in Bangladesh the primary as well 0:12:24.040 --> 0:12:27.040 as India to a certain extent, the primary root of 0:12:27.040 --> 0:12:30.160 transmission seems to be a little bit more directly due 0:12:30.200 --> 0:12:35.240 to bat contact, but via raw date palm SAP that's 0:12:35.320 --> 0:12:39.360 contaminated with either the saliva or perhaps the urine or 0:12:39.400 --> 0:12:43.839 feces from infected bats because apparently bats also love raw 0:12:43.920 --> 0:12:48.320 date palm sap just like humans do. So then humans 0:12:48.800 --> 0:12:53.319 essentially ingest this contaminated SAP and then become infected that way. 0:12:53.360 --> 0:12:55.959 There also have been cases where humans might have come 0:12:56.000 --> 0:12:59.280 in direct contact with bats or bat feces, bat urine 0:12:59.320 --> 0:13:03.080 something like that and gotten infected, like truly directly from bats. 0:13:03.440 --> 0:13:07.080 And this is ingestion. This is through ingestion. 0:13:08.440 --> 0:13:10.800 As far as I could tell. Yeah, I mean it's 0:13:10.800 --> 0:13:12.840 coming in contact with this date palm sap and what 0:13:12.880 --> 0:13:14.120 you do with it is you drink it. 0:13:14.200 --> 0:13:19.840 So yes, But like when we're like thinking about pigs 0:13:20.160 --> 0:13:23.040 and stuff like that, like is the contact again through 0:13:23.240 --> 0:13:24.239 or is it respiratory? 0:13:24.320 --> 0:13:28.120 Like what great question? Great question with pigs and intermediate hosts. No, 0:13:28.200 --> 0:13:32.120 it's not necessarily ingestion. You could get infected from contaminated meat, 0:13:32.120 --> 0:13:35.400 but even then it isn't necessarily from ingesting the meat, 0:13:35.920 --> 0:13:37.559 because if you cook it then you're going to be 0:13:37.640 --> 0:13:41.920 killing this virus. It's it's heat labile, but it's getting 0:13:41.960 --> 0:13:46.800 in contact with things like respiratory secretions or bloodborne products, 0:13:46.840 --> 0:13:50.560 like anything from this animal that has virus in it 0:13:51.240 --> 0:13:56.400 could then be transmitted to people. But the part that 0:13:56.480 --> 0:14:01.120 makes this virus a BSL for a Biosafety Level four pathogen, 0:14:01.440 --> 0:14:05.120 a pathogen of pandemic potential is that in many of 0:14:05.160 --> 0:14:09.319 the outbreaks there is also evidence of person to person transmission, 0:14:09.679 --> 0:14:14.760 and this is usually with contact with respiratory secretions, but 0:14:14.840 --> 0:14:18.560 it's very likely that other bodily fluids can also transmit. 0:14:18.640 --> 0:14:21.040 It's just that respiratory secretions are thought to be the 0:14:21.080 --> 0:14:24.240 main component of transmission when it's person to person. 0:14:40.920 --> 0:14:47.480 Question, does the strain or the root of transmission originally 0:14:47.560 --> 0:14:50.280 if it's a spillover event, does the strain then impact 0:14:50.360 --> 0:14:53.920 the ability of it to become transmitted person to person? 0:14:54.600 --> 0:14:59.040 And is that more likely from like the like from 0:14:59.040 --> 0:15:02.400 that direct to human rather than batpig human? 0:15:03.440 --> 0:15:08.520 Excellent questions. So yes, the first part of the question. 0:15:08.640 --> 0:15:10.160 So the first part of the question is do the 0:15:10.200 --> 0:15:12.640 strains seem to make a difference in whether they're transmitted 0:15:12.680 --> 0:15:16.360 person to person. The two main strains are the strain 0:15:16.840 --> 0:15:20.000 from the kind of original outbreak or couple of outbreaks 0:15:20.000 --> 0:15:23.720 in Malaysia, and then the strains that were first identified 0:15:23.760 --> 0:15:27.479 in Bangladesh. Those are kind of the two main lineages. 0:15:27.600 --> 0:15:30.680 It seems we have a lot more data on strains 0:15:30.720 --> 0:15:34.200 from Bangladesh, like you know, sub strains or whatever from 0:15:34.240 --> 0:15:38.920 Bangladesh than we do from Malaysia. But in those initial outbreaks, 0:15:39.000 --> 0:15:42.760 there was very limited evidence of person to person transmission 0:15:43.040 --> 0:15:46.440 from what I could tell, not even like definitive evidence 0:15:46.480 --> 0:15:49.800 of person to person transmission in those first Malaysian outbreaks. 0:15:50.240 --> 0:15:53.400 So is that because those strains are less likely to 0:15:53.440 --> 0:15:56.680 be transmitted person to person? Perhaps, but I don't know 0:15:56.720 --> 0:15:59.640 that we have as much evidence to say for sure 0:16:01.120 --> 0:16:03.280 the strains in Bangladesh are more likely to be a 0:16:03.280 --> 0:16:06.560 transmitted person to person, But I don't think that we 0:16:06.640 --> 0:16:09.120 have data, at least I didn't see any on whether 0:16:09.160 --> 0:16:13.280 it's more likely to happen like how that primary person 0:16:13.360 --> 0:16:15.760 got infected, whether it was from date palm, SAP or 0:16:15.800 --> 0:16:20.360 from an intermediate host or from a bat. However, it's 0:16:20.520 --> 0:16:24.760 only about ten percent of people that seem to be 0:16:25.640 --> 0:16:30.880 spreading this person to person, which is very interesting. Overall, 0:16:30.960 --> 0:16:34.280 it's a pretty low rate of person to person transmission 0:16:34.440 --> 0:16:38.920 in the outbreaks that have been studied. However, there is 0:16:39.240 --> 0:16:43.560 plenty of evidence that that chain of transmission can live 0:16:43.640 --> 0:16:46.360 on for like several viral generations, if that makes sense. 0:16:46.400 --> 0:16:49.400 So one person out of every ten who gets infected 0:16:49.560 --> 0:16:53.480 is going to transmit it to someone else, but then 0:16:53.640 --> 0:16:56.400 the person that they transmit it to can transmit it 0:16:56.440 --> 0:16:57.440 to someone else as well. 0:16:57.920 --> 0:17:01.880 So it's like there's something about that person that makes 0:17:02.040 --> 0:17:05.840 them makes the virus like, hey, this is great. 0:17:06.320 --> 0:17:09.520 Exactly we saw. I think everyone's familiar with the idea 0:17:09.560 --> 0:17:12.960 of a super spreader after COVID. It's that same kind 0:17:13.000 --> 0:17:16.040 of idea. We don't know right now. Is that a 0:17:16.560 --> 0:17:19.639 characteristic of the virus that happened to infect that person, 0:17:19.800 --> 0:17:22.640 or is it a characteristic of certain people that makes 0:17:22.640 --> 0:17:28.879 them super spreaders in this case, we definitely do not know. Okay, okay, yeah, 0:17:29.080 --> 0:17:31.640 So that's kind of how this is transmitted, right It's 0:17:31.800 --> 0:17:33.920 a lot of different ways, and it really does depend 0:17:34.560 --> 0:17:38.439 on the circumstances, and we'll get into more of the 0:17:38.480 --> 0:17:41.280 ecology of this virus later when we talked to doctor Murckey, 0:17:41.480 --> 0:17:45.000 But let's then talk about more of what this actually 0:17:45.000 --> 0:17:47.800 looks like when a human does get infected, and I'm 0:17:47.840 --> 0:17:51.560 focusing on humans, but again, this is a zoonotic pathogen, 0:17:51.640 --> 0:17:56.440 so this is infecting and living amongst bats very readily. 0:17:57.080 --> 0:18:02.040 And when it infects our domestic animals like daw cats, pigs, horses, 0:18:02.400 --> 0:18:05.359 it does tend to cause symptomatic disease for the most part, 0:18:05.560 --> 0:18:08.879 but it really varies how sick these animals get, So 0:18:08.920 --> 0:18:10.600 I'm not going to get into detail on all of that. 0:18:11.560 --> 0:18:12.919 Let's focus on humans, shall we. 0:18:13.800 --> 0:18:14.359 Let's do it. 0:18:14.880 --> 0:18:17.960 Once a human gets infected, the incubation period tends to 0:18:18.000 --> 0:18:21.359 be between four days to two months, which is a 0:18:21.480 --> 0:18:25.480 huge range, but over ninety percent of people who have 0:18:25.600 --> 0:18:31.080 symptoms will have them within two weeks. Now, how many 0:18:31.080 --> 0:18:34.760 people are going to have symptoms, We have no idea. 0:18:36.359 --> 0:18:39.680 You can find numbers, but this is such a rare 0:18:40.000 --> 0:18:44.760 and understudied pathogen still that estimates range between one percent 0:18:44.840 --> 0:18:48.000 and forty five percent of people that are asymptomatic, depending 0:18:48.040 --> 0:18:51.360 on what the study is so it's. 0:18:50.200 --> 0:18:52.600 The biggest range we've encountered on this podcast. 0:18:52.680 --> 0:18:54.080 It's a meaningless range. 0:18:54.240 --> 0:18:56.840 It's entirely it's not one hundred percent. 0:18:58.240 --> 0:19:04.239 Not everyone we know that this is true. So in 0:19:04.280 --> 0:19:07.160 any case, there are some proportion of people who are 0:19:07.240 --> 0:19:10.280 likely asymptomatic based on like ero logic studies that we 0:19:10.359 --> 0:19:15.520 have seen. Okay, but for people that are symptomatic, this 0:19:15.560 --> 0:19:20.080 is a really terrible pathogen. Symptoms tend to start after 0:19:20.119 --> 0:19:25.120 this incubation period with pretty nonspecific kind of prodrome. These 0:19:25.160 --> 0:19:30.800 are symptoms like a fever, headaches, muscle aches, maybe even vomiting, 0:19:31.240 --> 0:19:34.120 but really nothing that would make you go, oh, this 0:19:34.200 --> 0:19:37.520 sounds like nepavirus, right, It sounds like any other of 0:19:37.560 --> 0:19:40.480 a million infections that we've covered on this podcast, or 0:19:40.520 --> 0:19:42.960 like one hundred and something that we've covered on this podcast. 0:19:44.160 --> 0:19:48.040 But generally within a week, within a number of days, 0:19:48.400 --> 0:19:51.600 you start to see signs of central nervous system infection. 0:19:52.880 --> 0:19:57.120 So this looks like things like altered mental status. Very 0:19:57.160 --> 0:20:01.199 often we can see signs of brainstem involve and so 0:20:01.320 --> 0:20:05.439 you might see changes in reflexes. Usually it would be 0:20:05.520 --> 0:20:08.600 like a loss of reflexes or a decrease in reflexes. 0:20:09.480 --> 0:20:12.639 But there's some literature where we can see like loss 0:20:12.640 --> 0:20:17.520 of very specific reflexes that are associated with that brain 0:20:17.560 --> 0:20:20.960 stem or that lower part of your brain dysfunction. These 0:20:20.960 --> 0:20:24.720 are things like if you turn someone's head side to side, 0:20:25.520 --> 0:20:28.439 in a person whose brainstem is intact but who maybe 0:20:28.480 --> 0:20:32.280 isn't all the way conscious, their eyes should move in 0:20:32.359 --> 0:20:36.000 the opposite direction that their head is turned, like a 0:20:36.160 --> 0:20:38.120 like those creepy dolls that you had in your grandma's 0:20:38.119 --> 0:20:40.600 house growing up. This is called the doll's eye reflex. 0:20:41.280 --> 0:20:44.160 If this doesn't happen, then the eyes just stay midline 0:20:44.200 --> 0:20:47.119 as the head moves. That's a loss of that reflex, 0:20:47.200 --> 0:20:50.440 which is very severe, so it suggests loss of brain 0:20:50.480 --> 0:20:54.560 stem function. There's a lot more detail to that that. 0:20:54.680 --> 0:20:57.640 Don't please ask me about that reflex because I learned 0:20:57.680 --> 0:20:58.080 it once. 0:20:59.200 --> 0:21:02.240 But there are other like what I guess, other diseases 0:21:02.280 --> 0:21:06.120 that affect the brain stem, right, what examples. 0:21:06.840 --> 0:21:09.119 You know, that's a good question. Any kind of meningitis 0:21:09.160 --> 0:21:12.639 that is affecting the brain stem. Yeah, yeah, okay, But 0:21:12.720 --> 0:21:15.720 you also see things like other reflexes, like your pupillary 0:21:15.800 --> 0:21:19.840 reflex or even just loss of muscle tone. You can 0:21:19.920 --> 0:21:22.480 also get instead of a loss of muscle tone, you 0:21:22.480 --> 0:21:27.160 can get these jerks like myoclonic jerks. You can see seizures, 0:21:27.640 --> 0:21:31.359 you can see any number of these neurologic signs and 0:21:31.400 --> 0:21:34.919 symptoms which are just telling us how severe the brain 0:21:35.280 --> 0:21:40.160 infection is in this case, and people tend to deteriorate 0:21:40.520 --> 0:21:44.879 very rapidly. Nepavirus, like I said, is an incredibly fatal 0:21:44.920 --> 0:21:49.040 disease and usually within a matter of days. Forty to 0:21:49.200 --> 0:21:52.840 ninety percent of people in most outbreaks die within a 0:21:52.920 --> 0:21:53.360 number of. 0:21:53.359 --> 0:21:57.080 Days, So it's two weeks you get infected, two weeks 0:21:57.119 --> 0:22:00.000 later you start to have these sort. 0:21:59.720 --> 0:22:04.600 Of nonspecific specific symptoms, and within a couple of days 0:22:04.800 --> 0:22:11.280 in nervous system involvement, coma and death. Death. In some outbreaks, 0:22:11.600 --> 0:22:14.439 there also does seem to be a substantial amount of 0:22:14.760 --> 0:22:18.879 respiratory involvement, though not all outbreaks, which is very interesting. 0:22:19.840 --> 0:22:23.480 So respiratory involvement looks like a cough, it can look 0:22:23.520 --> 0:22:27.200 like an atypical pneumonia, which we've talked about on this podcast, 0:22:27.320 --> 0:22:29.800 just means that on a chest X ray it doesn't 0:22:29.800 --> 0:22:33.800 look like a very classic pneumonia. You can have. 0:22:33.960 --> 0:22:38.880 I know, these are words you can't define h typical 0:22:38.920 --> 0:22:43.240 pneumonia by saying it's just not your classic pneumonia. 0:22:43.359 --> 0:22:45.760 So on a chest X ray, it would look like 0:22:46.040 --> 0:22:50.160 kind of patchy involvement in the whole lungs rather than 0:22:50.520 --> 0:22:53.159 one area of your lungs that's fully infected with a 0:22:53.240 --> 0:22:55.800 bacterial pathogen. That's okay, I think of when we think 0:22:55.840 --> 0:22:57.040 of pneumonia. 0:22:56.520 --> 0:22:57.440 Of classic pneumonia. 0:22:57.440 --> 0:23:00.520 Okay, But in general, you're going to see some degree 0:23:00.520 --> 0:23:05.040 of respiratory distress if you have a respiratory involvement. But 0:23:05.280 --> 0:23:09.120 this hasn't happened in all the outbreaks, so we don't 0:23:09.119 --> 0:23:12.160 really have a great sense of like when or why 0:23:12.200 --> 0:23:17.480 this is happening. And because this is such a fatal infection, 0:23:18.040 --> 0:23:22.119 we don't have that much data in all honesty on 0:23:22.200 --> 0:23:25.520 a lot of these signs and symptoms. What we do 0:23:25.720 --> 0:23:30.080 know is that in people who survive, something like twenty 0:23:30.160 --> 0:23:34.800 percent of them have some degree of like residual neurologic dysfunction, 0:23:35.240 --> 0:23:40.600 which can again really range, and some proportion in some 0:23:40.720 --> 0:23:44.960 of these outbreaks seem to also have like a relapsing encephalitis, 0:23:45.320 --> 0:23:48.439 so looks like a new infection, but it's just a 0:23:48.560 --> 0:23:53.720 relapse months or even years after the initial infection. How 0:23:53.760 --> 0:23:56.240 does this happen? I have no idea. 0:23:56.400 --> 0:23:59.440 Yeah, and they've cleared the virus from their system. 0:24:00.080 --> 0:24:02.000 That's a great question. Do we know that for sure? 0:24:02.160 --> 0:24:03.600 I don't know that we know that for sure. 0:24:03.840 --> 0:24:09.639 Okay, Okay, two questions. Okay, how environmentally stable is this virus? 0:24:09.920 --> 0:24:10.920 I knew you were going to ask. 0:24:11.000 --> 0:24:16.679 Okay, number two, when is someone? If someone is infectious 0:24:17.080 --> 0:24:21.640 person to person, at what point are they infectious? Pre symptoms, 0:24:21.920 --> 0:24:22.439 et cetera. 0:24:23.440 --> 0:24:26.399 Yeah, these are really good questions. So this virus is 0:24:26.600 --> 0:24:29.960 fairly environmentally stable, which is part of how it can 0:24:30.000 --> 0:24:34.320 be transmitted In things like date palm SAP. This virus 0:24:34.320 --> 0:24:37.719 can persist for days outside of a host. One paper 0:24:37.720 --> 0:24:40.680 that I read said that on some fruits and juices 0:24:40.720 --> 0:24:43.240 that they have studied, it can live for up to 0:24:43.320 --> 0:24:47.479 three days and still be transmissible in some cases. In 0:24:47.520 --> 0:24:50.080 some studies where they have kept it colder, like around 0:24:50.119 --> 0:24:53.280 twenty two degrees celsius, it can last for up to 0:24:53.400 --> 0:24:57.440 seven days in something like a date SAP, But even 0:24:57.480 --> 0:25:00.280 at higher temperatures it can survive for like a couple 0:25:00.280 --> 0:25:05.439 of hours. So it's a pretty environmentally stable virus. 0:25:05.680 --> 0:25:09.200 Okay, Now, how. 0:25:08.960 --> 0:25:12.520 Transmissible are people or like when are people most transmissible? 0:25:13.080 --> 0:25:18.240 We don't really know. That's a great question because we 0:25:18.480 --> 0:25:24.560 know that there is some degree of asymptomatic infection. There's 0:25:24.600 --> 0:25:27.520 a really important question of if you are asymptomatic, can 0:25:27.560 --> 0:25:30.040 you still spread this person to person. I don't think 0:25:30.080 --> 0:25:33.919