Oliver writes:

If you haven’t seen this yet, it is the largest data set published so far from China on n-CoV-whatever-its-name-is-now (72,314 cases). 

It has more detailed age distribution data and epi. curves than I’ve seen before.

Interestingly, although the confirmed cases are 50/50 male/female, the fatalities are 2/3 male and 1/3 female. That may turn out to be related to the prevalence of smoking among Chinese men vs. women (in 2010, 54% of Chinese men smoked vs. 2.6% of Chinese women).


Mark writes:

Dear TWiVers,

Here is a candidate paper for a “TWiV Snippet”. I found it after hearing Chinese authorities were using HIV drugs in patients infected with nCoV2019. I read a news article in which a Chinese MD claimed he contracted nCoV2019 and cured himself by taking anti-HIV drugs.    After some googling I found this paper which presents clinical results using ritonavir and ribavirin drugs against another coronavirus – SARS. Here is the URL: https://thorax.bmj.com/content/59/3/252 

Certain to warm the hearts of Vincent and listeners is that they’ve used plaque assays – see figure 1.

All the best.


Anonymous writes:

I am catching up with the latest TWIV episode today and felt compelled to write in. The TWIV hosts commented on Dr. Zhengli Shi’s statement that “the novel 2019 coronavirus is nature punishing the human race for keeping uncivilized living habits”. I certainly agree with the comment that nature really does not care (or “give a damn”) about the mankind to punish us, but I echo the feeling of Dr. Shi that this is perhaps a punishment for bad human habits. I believe what she referred to is the sale and consumption of wild animals in some parts of China, which could turn out to be a major factor for initiating the current epidemics. As reported widely in the news media, pangolins are now considered to be the likely intermediate hosts transmitting this coronavirus to humans. There is also a paper published in October last year that some Malayan pangolins illegally smuggled into China were infected with unknown coronaviruses and died from lung diseases. If further studies ultimately confirm this pangolin connection, I hate to say that we are indeed collectively “punished” “published” by some people’s demand of pangolins as delicacy or medicine and by authorities not doing enough to stop the illegal sale and transport of pangolins. This could be an important lesson from nature for the importance of respecting nature and protecting animal habitats.    

As a virologist of Chinese origin, I have been captivated with all the coronavirus-related news, including popular posts in the Chinese social media. I have witnessed from the Chinese social media quite widespread acceptance of various conspiracy theories on the origin of the current coronavirus and the associated backlash against virus research in general. Even some of the highly educated friends of mine in China openly question whether the Wuhan coronavirus is man-made or leaked from the lab by accident. Dr. Zhengli Shi has been the public enemy number one in some Chinese social media circles, because she happens to conduct coronavirus research in the city where the current epidemics started. I think the main reason for this phenomenon is the public mistrust of the government and any entities connected with the government in China. Independent and scientific voices like TWIV could have been very valuable in China for defeating the conspiracy theories. 

I’d love to hear what TWIV hosts think about the pangolin connection. I myself am leaning towards the possibility that pangolins are dead-end hosts that have gotten the viruses from bats or some other animals. Even as the dead-end hosts, they may still play a critical role in transmitting the virus to humans. Pangolin scales have been used in Chinese traditional medicines for over a thousand years. This is one reason China is the number 1 destination for smuggled pangolins. Chinese traditional medicine is a highly controversial topic in China. Many Chinese people including the government promote the Chinese traditional medicines as a culture heritage and believe in their healing power (even against the new SARS-CoV-2). Many other Chinese, including myself, consider the traditional Chinese medicines total bullsh*t. I think some of these traditional medicines do more harm than just being the benign placebo. I speak out against the traditional medicines whenever I can, but many people just believe in the anecdotal evidence and it’s really hard to change their views. 

There is a widespread public fury over Chinese CDC and its scientists. Chinese CDC has the dual function of disease control like the US CDC and research and development like the US NIAID. Because the public was only informed about the human-to-human transmission of the Wuhan coronaviruses sometime in January , while the Chinese CDC scientists published a retrospective report of early cases in NEJM indicating human-to-human transmission in December last year, there is an accusation that Chinese CDC scientists prioritized publications in international journals over disease control in China. The head of Chinese CDC George Gao has been the prime target of the public anger in the Chinese social media. The general public appears to demand Chinese CDC focus on disease control not research or publications. 

This epidemics also brought the gain-of-function research and biosafety issues to the attention of the general public in China. The 2015 Nature Medicine paper on recombinant coronavirus from Ralph Baric’s group was widely distributed in Chinese social media, bringing a lot of fear over gain of function research. There are also a lot of concerns over biosafety of virology research. Some people even suggest that virology research should not be performed in large cities.   

From my observation of the Chinese media, it looks like the Chinese government is likely to reform disease control institutes like Chinese CDC, establish tighter biosafety regulations, and more strongly enforce laws protecting wild animals in the future.

These issues are known to most Chinese American virologists, because our attention has been largely drawn to this epidemic in the last few weeks. If you talk to any Chinese virologist here, they may tell you the same things. 

I may add that I think Chinese CDC is being wrongly targeted by the public, as ultimately it’s some Chinese officials higher up than the head of CDC who decide when to announce to the public that there are human-to-human transmissions. Because the whole country has literally been shut down by this epidemic, the public just needs some outlets to release their anger. It is probably less dangerous for the public in China to criticize CDC and scientists than to criticize the central Chinese government. There is so-called “tossing the wok” (Chinese equivalent of passing-the-buck) phenomen on the Chinese internet for shifting the blame for this epidemic from one entity to another. 

Anonymous writes:

Hello, I’ve been listening to your podcast since the outbreak of the Corona Virus and I’m very glad I found you guys, it’s reassuring listening from specialists in the field. I’m passionate about biology and everything related although I never followed up with a career in this area, just to say I became a listener and I do enjoy the chatting to lighten up a little. 

 I currently reside in Singapore, as you know we are having a big number of confirmed cases (specialty compared to the size of the country) and in the last two days we had several confirmed cases of local transmissions.

The advice to health practitioners is to be on the lookout for people who traveled to China, Chinese nationals or people who had contact with infected people.

I have three young kids, last January 27 one of them started to have fever and stomach ache, next evening my 2nd child started having fever and cough, and the third child started having had fever on the next morning. What they had was quite nasty, fever never subsided even with paracetamol, they were very tired, body aches, red eyes, vomiting and not eating, coughing but not severely.

I took them to see a doctor on the day four, as we never been to China or in contact with someone who been we were considered not at risk, the doctor promptly diagnosed as a viral disease and one became ill in January and a swab came positive for Influenza B. The doctor said that if they didn’t have fever they could come back to school. The recommendation from health minister is 24 hours no fever. So I kept them the whole week at home, after 6 days on Sunday they woke up much better, talkative, happy, no fever, eating, so on Monday I checked the temperature, no fever, I sent them to school. They are taking all children temperature three times a day in school. They were really tired for another two days and coughing until now.

So, the questions are: 

1. Is it safe that the government is only testing the suspicious cases? 

2. Having been diagnosed with influenza B does it means they didn’t contract another virus?

3. Is it correct that after 24 hours no fever you are not contagious? In case of the Coronavirus 2019 what is the process for being discharged?

I think those are the questions, thank you so much for your podcast.

Vr: CDC published guidance for healthcare professionals on the clinical care of  COVID-19 patients.

Liping writes:

I have been reading the latest Lancet papers on the Wuhan Coronavirus. https://www.thelancet.com/action/showPdf?pii=S2213-2600%2820%2930066-7 and I’d like to pick your brain on the following questions:

  1. Patients still test positive after discharging and still shed virus, does that indicate that this virus is similar to Hepatitis B virus such that we can be chronically infected by it, whether or not it manifests itself depends on how strong our immune system are?
  2. They find virus in the faecal martial and much like SARS in HK, there has been people be infected via the bathroom pipeline transmission route. Are their any know good practices to minimize the aerosol in the bathroom system?

Thank you for taking the time. Fingers crossed that my questions get picked for the next podcast!

Best Regards,


Jerald writes:

Hello.   I appreciate your podcast.  Thank you. I have two questions:

1.  What is it that makes the report by Ji et. al. so unconvincing regarding snakes as a reservoir for the new coronavirus?  It seems that their data did not carry much weight in your discussions. Ji, W., Wang, W., Zhao, X., Zai, J. and Li, X. (2020), Homologous recombination within the spike glycoprotein of the newly identified coronavirus may boost cross‐species transmission from snake to human. J Med Virol. Accepted Author Manuscript. doi:10.1002/jmv.25682

2.  If this outbreak were to gain traction in the USA in the same way it has in China, do you feel we have the clinical resources (ICU beds, O2, respirators  staff, , etc.) to manage it? As a physician, I am concerned the US public is getting a nerfed and edited version of the the clinical issues and outlook.

Thank you,


Chengxin Zhang, Wei Zheng, Xiaoqiang Huang, Eric W. Bell, Xiaogen Zhou, Yang Zhang

bioRxiv 2020.02.04.933135; doi: https://doi.org/10.1101/2020.02.04.933135]

Cassidy writes:

Thank you so much for your common sense and logic in covering the 2019-nCoV outbreak in Wuhan. With the insanity of the 24 hour news cycle I was so glad to find a podcast from researchers/practitioners/researchers in this field that was easy to listen to, full of great information and provided a plethora of links to the actual research papers and articles covered. I’m super analytical and thrive on deep dive research work so I’ve loved reading all of the linked papers and articles.

My mother is a doctor, my father is a science educator and my personal background is in journalism and finance (but I’m currently an artist and run a small animal rescue farm for elderly dogs, all kinds of reptiles and even a flock of poultry). All of this has taught me from an early age to believe strongly in going right to the source of the knowledge. You all are doing that and it is AWESOME.

I heard you all  discussing the video clips of the government doing spraying in Wuhan and the wider Hubei province and was curious about exactly what they were using and whether or not it would actually work (given your references article about influenza viruses in mucus). 

Here is one article I found that says in many places they are using bleach and other household disinfectants.  The writer also spoke to Joe Drake who is CEO of Decon Seven who was actually in the closed “seafood” market in September. They make a hydrogen peroxide product that was originally designed to cleanup biological and chemical warfare agents but is now being sent to hospitals in China to help disinfect and slow the spread of the virus.  Their product works on surfaces for up to 8 hours before degrading into non-potable water so it lasts longer than a bleach and water spray.

The article also does a great job of explaining why the widespread fogging and spraying isn’t all that useful, wastes money and materials that could be focused elsewhere and could give people a false sense of security. The crazy part is they are not just spraying streets with it. They are also spraying hospital workers and patients with bleach water when they leave the hospital!


Indonesia also sprayed evacuated nationals with some sort of antiseptic as they disembarked from the plane before going into isolation on an island.


If you check out the Global Times Twitter account it is filled with lots of interesting tidbits from Wuhan about useful things people are doing to actually help stop the spread of Corona virus. My favorite was a DIY device created so people could push an elevator button with a kick of the foot instead of their hands.

 Companies are also shipping robots to Wuhan for use inside hospitals to do disinfecting using ultraviolet light and disinfecting sprays. My local hospital actually has a similar robots for sanitizing ER bays and patient rooms on most floors in-between patients

I also saw a video of self driving robots delivering medical supplies

I’d love to hear y’alls take on using technology to prevent spread in a future episode. Clearly working remotely is one way but This is pretty smart 

Obviously there is also a good bit of government propaganda which is also interesting to analyze so BOLO for it 

P.S. the Twitter is also filled with examples of people who lied about travel history to avoid being put in isolation. One woman lied and because she did, she missed valuable time to be treated and died. 44 people had to go into quarantine because of her. It’s clear closing an entire province isn’t really working.

Keep up the great podcast!


Brendan writes:  

Hi TWiVers,

Wanted to send you an update from Chengdu as well as ask about possible spread of this virus between mammal species (sorry in advance for the lengthy email). First off the weather is very pleasant here with temperatures in the mid to high teens Celsius and mostly sunny skies. 

Life here has continued to be under (mostly) self imposed (mostly) quarantine. All non-essential public spaces remain closed. That’s pretty much everything except hospitals, convenience stores and supermarkets. I heard a joke in Chinese which paraphrases to: “Your Chinese New Year vacation is almost over. Alert: Congratulations, your vacation has been extended!” Given the co-incidence of this outbreak with the holidays that’s really what it feels like. 

For those who haven’t spent time here note that Chinese residences are primarily clustered in gated communities.  This doesn’t apply just to high income areas, almost all communities old and new are set up this way. The social distancing measures have become much more organized lately with each housing complex requiring residents to get a temporary ID card for entry and exit. Everyone going in and out gets a temperature check but those who don’t live there go through a longer health check and registration process before being allowed in. Also, yesterday on Feb 9th, the police came and did a separate door by door registration. This was ostensibly to do an up to date census of where everyone is and aid with tracking contacts of infected individuals. For the moment we still have limited freedom of movement around the city (public transit is still running) but I’m braced for that to change any time.

I can’t tell anything about the efficacy of these measures though. As of around Feb 5th Chengdu has confirmed local human to human transmission with 120 cases and the growth in cases per day is around 5%. That’s about the same as Wuhan although the magnitude is much less. If you look at the curves on the Hopkins website it does look like case growth is slowing though. This is all with the caveat that the confirmed case metric is problematic. As you all have noted, the figure is certainly under reported. Also there may be some bias in testing and/or reporting between areas. I could imagine relatively affluent cities have more testing and over-report compared to lower income areas for example. Chengdu might be really better off than other parts of China, though, as the Sichuan province governor Yan Li has a public health background. He was on the SARS expert panel in 2003 after which he headed the Chinese FDA before becoming the governor. While the official response has been problematic (early January in Wuhan for example), I want to echo the shout out on TWiV to the public health community here: for now at least it seems they are being given a lot of leeway to do their best. 

Having regularly listened to TWiV for a while I’m personally not too afraid of this virus. I’ve got access to sources like TWiV and promed mail which show what the risk factors are and put the outbreak in context (compared to other pathogens or the danger of crossing the street for that matter). The thing I worry about is the public reaction and impact on the economy. Businesses were supposed to open today on Feb 10th but that’s been pushed back. Based on how the political system works here I foresee that remaining the status quo. This is because, regardless of the efficacy of control measures, the political risk of letting businesses operate and then seeing an uptake in cases is too high for local authorities. However, as Vincent noted in his virology course video the other day, if the ratio of confirmed to total cases is 10% then maybe the ultimate control measure will end up being immunity. Personally I’m rooting for some of the anti-virals being trialed in Wuhan to show efficacy for reducing severe outcomes. If that happens then maybe this starts to look more like seasonal flu in terms of severity, and people can get on with life. 

Speaking of getting on with life, I was out for a walk the other day and saw a guy struggling to put a doggie surgical mask on his husky. At first I laughed to myself, then I thought, well, there must be a non-zero chance this could infect dogs (higher than snakes at any rate). Have dogs been investigated for other human pathogenic coronaviruses before? What about non inbred lab mammal strains? I can imagine a scenario where this gets into some kind of domesticated animal and has unrecognizable transmission before jumping back to humans next winter. Maybe that guy should forget the mask and teach his dog to wash its paws alongside sit and roll over.

Anyways thanks again for all you do, I’m almost caught up to the 2014 Ebola outbreak in the TWiV back catalog so that will be interesting to listen to in parallel to this. 

All the best!


Bonnie writes:

Dear TWIVsters,

Thank you for the excellent science-based info on the COVID19 situation. I am an infectious disease doctor and would like to point out an important factor in diagnosing this infection (and all respiratory pathogens that use nucleic acid probes for testing): specimen collection. This of particular concern now that China has transitioned to a much more problematic ‘clinical diagnosis’ based more on clinical symptoms than PCR testing. While it may seem trivial how a healthcare worker jams a swab in someone’s nose or throat, technique is important. If anterior nares (front of nose) swabs or ‘side of mouth’ swabs are done rather than true posterior nasopharynx or oropharyngeal swabs, the sensitivity drops-dramatically! We have shown this to be true repeatedly with diagnosis of influenza and other respiratory pathogens, and I am disappointed it has not been mentioned more in discussions about the PCR tests “MIssing” the diagnosis, and stories about people who were “positive, then negative, then positive again”. We often see patients admitted from the ER with the (perhaps carelessly) collected flu test who miraculously are Flu positive by the time they are admitted. Like SO many cultures and diagnostics in infectious disease, specimen collection and handling is critical. I warn my patients about the unpleasantness of a nasopharyngeal swab, and (jokingly) tell them if it doesn’t cause a “wincy face” reaction, we haven’t collected specimens from where the viruses reside. Thanks for helping to get the word out. 

P.S. I am sorry Vincent feels MDs “are not scientists”. While most of us are not researchers, to be sure, THIS M.D. certainly knows the mechanism of action for acyclovir, and MANY other mechanisms for the hundreds of antimicrobials, etc I prescribe. I’m sorry if so many of your med students have already lost the love of science that inspires many of us to choose our profession. It’s the science and the “Cool Case” WOW moments that get us through the day many times. Thanks for promoting the science and all things Microbe.

Judy writes:

I live in Singapore as of this moment there are 43 cases of which 6 ended up in the ICU. Given the government here is highly functional and transparent I trust these numbers more than any coming out of, well, anywhere including China. That implies a 14% rate of cases becoming severe, although fortunately there have not been any deaths. Also, several cases had mild symptoms for a week before being severe enough to be sent to the hospital for screening.

In all the stats I’ve seen about this virus, none mentions what percentage of cases go on to require critical care. That would make a big difference in death rates especially compared to the regular flu. If, in the case of Wuhan, the health system is in crisis that would mean a higher death rate. If, as in Singapore, that could mean a higher survival rate due to the availability of supportive care. This makes the death rate highly variable depending on how wide spread the virus becomes and consequently and more importantly how overwhelmed the local healthcare resources become. It would be interesting to see if this statistic exists outside of Singapore. I tried to google and all I get are number of deaths and infections. No rates of cases requiring ICU or becoming “serious” (however that is defined).

Also, it’s concerning how many had mild symptoms that only became severe after a week. In Singapore there are several cases where people went to an urgent care clinic with mild symptoms two or three times before becoming sick enough to be sent for coronavirus screening. These folks were not “profiled” as being susceptible to the virus as they had no recent travel history or contact with anyone from China so were not sent for screening immediately. I haven’t seen many stats regarding onset of initial symptoms to being severe enough to be diagnosed. There maybe thousands of folks infected with the Coronavirus who have a mild cough and fever and think nothing of it. Does that mean in 7-10 days we will see a spike in cases that become severe enough folks will seek treatment at the hospital? Does this explain the apparent low rates of transmission outside of China? Is it just because there hasn’t been enough time for the severe cases to manifest and “be found?”

I’m sure the WHO is all over this, but am wondering why there are so few articles asking these questions. Or maybe I’m not seeing them as most of what I’m looking at are mainstream publications.

Would love your expert commentary! PS. Being in Asia and closer to the China pandemic folks here are “panicking” a bit, so it’s hard to escape the news!



Anthony writes:

Bats shedding viruses

The Central Park Zoo has bats:


I don’t know how large the enclosure is.

The guano certainly can be collected without disturbing the bats.  The bats’ resting temperature can be determined — albeit not precisely — non invasively.  I’d hope that the guano is monitored for viruses and the temperature is checked as this information could be valuable.  

I speculate that pregnant and nursing bats shed more virus.

Cam writes:

Hi TWIV gang,

It has been a few years since I have felt compelled to write to you guys but I have listened to your discussions for years.    What do you think about the incubation period? All of the assumptions around the nCoV have been based around SARS and MERS though there is credible information that the incubation period may be as much as 24 days, which if this is the case then looking at mild to asymptomatic cases that might be able to spread the virus,    what do you think that the true R0 could be and how self quarantines based on the 14 day period could be a weak link? Considering the infection rate of the Petri Dish of the Seas, Diamond Princess, what do you think the actual R0 is for nCoV? IMHO the CFR is pretty low, but the infection rate is pretty high, we are up to around 1000 dead and officially not that many people infected for that kind of CFR.  How do you view travel restrictions? The WHO seems to want to keep people travelling, do you guys agree with that stance? Also there are a lot of posts saying to only wear masks if you are infected but not to if you are healthy. IMHO a mask is better than not, especially if working in an infected site. Droplet vs aerosol infection, do you think that this is an aerosol spread infection, especially considering the rapid spread, say compared to SARS?



Mario writes:


It’s -9C here in Montreal and we’re buried under about 15cm of snow. 

I am a long time fan of your show, and I’m really happy you folks are doing this series on 2019 nCoV.

My question is on the impact of poor data quality on decision making during times of major outbreaks and responses.   I have noticed a very heavy reliance on official Chinese government numbers for predicting mortality rates. In the last couple of episodes it was stated a few times that the upper limit on the mortality rates are around 2%, and that number of infections seem to be “contained” to China – and these two points have been repeated in the press often.

Do we have bias of over-relying on the official Chinese gov’t data simply because it is the only quantifiable data we have?   …because there seems to be a very significant amount contradictory anecdotal data “leaking” out as well. …and while it is poorer in quality, there is much more of it, and much seems to contradict the official numbers.   You mentioned in your previous episode that there is likely an under-counting (both due to limited testing resources, and also because the data is curated centrally), but the team (like the media) always seems to circle back to the Chinese data anyway. 

My question is how, in such a chaotic situation, do experts in outbreak response factor anecdotal data sources into their decision making – particularly when they contradict official numbers.  It seems like a challenge both from a statistical perspective, as well as a diplomatic one.

I’ll give you two examples, but as you can imagine, there are *many* these days…

1. This is a video of an interview with a Crematorium in Wuhan: https://www.youtube.com/watch?v=-KFxCqV1fPQ  (it’s important to listen to the end where the crematorium opens up about the contradiction in the “real” numbers of bodies they are cremating)

2. This is two news reports from Nepal about a “viral fever” that’s made several hundred people sick in the last week, killed two, and even put a number of young people in critical condition.



The question was asked on the show “Why haven’t we seen more cases internationally”. I wonder if in countries that owe so much of their economies to tourism – such as Nepal, Thailand, Vietnam, Laos – whether they are less vigilant in reporting the virus out of fear of sabotaging their economies.


Anton writes:

Now there is a significant number (463 CASES) of infections of the corona virus outside of China.

The death rate in China is 2.38%.

The death rate outside of China is 0.43%. See enclosed excel spreadsheet.

What can be the reason the death rates are so different. Are the 

treatments the same worldwide?

Are we helping China enough?



Ruaridh writes:

Hi there, 

I started listening to your podcast when this latest outbreak started and thought you might be interested in an update about what life is like in an average Chinese city at the moment. 

I live in xuzhou (pronounced something like Shoe Joe) in jiangsu province. A second tier city. Urban population 2-3 million, metropolitan pop around 10 million. There have been around 80 cases here. 

Xuzhou for the last week has implemented a curfew system where only one person per household can go out once every two days to buy essentials. In addition many roads have been blocked, funnelling traffic and pedestrians to check points where you must give your ID and submit to a temperature check. All restaurants and public places are closed, apart from McDonalds, Burger King and KFC, it seems. Leaving the house you must wear a face mask and you are temp checked if you go into a supermarket. My university classes will be online for at least ten weeks and it seems the primary and secondary schools are doing the same.  Although there are a few cars and people about, mostly the streets are quiet and deserted. 

A week or so ago a traditional Chinese remedy went viral on chinese social media, supposedly being able to cure the virus, there were long queues outside Chinese medicine pharmacies. There has also been a lot of propaganda against America. Saying that the USA hasn’t helped, they were the first to leave wuhan, they haven’t sent aid etc.    Posts showing aid from USA or the help that the cdc has offered are routinely deleted by government censors. 

I’ve added a few photos in as well from around the city and some videos of the queues. 

Hope you are all well. 







Vincent writes:

Dear Vincent et al. 

I’d like to highlight a website that analyses the phylodynamics of the Coronavirus outbreak:


Thanks for the show!

All the best,

Vincent Doublet


Dr. Vincent Doublet

Institute of Evolutionary Ecology and Conservation Genomics

University of Ulm 

89081 Ulm, Germany

Matthew writes:

Dear Good People at TWIV,

Grateful for your intelligent and informed discussion about COVID-19/SARS-COV-2.

Would like to hear your thoughts about the nationwide spraying of bleach and other “disinfectants” across China. 

Apparently, this is not nearly effective as actually wiping down surfaces in the places the virus is most likely to have settled on. And what about the health dangers of inhaling bleach, even if diluted (surely not as bad as COVID-19, but can’t help but having a major impact by dumping that amount of chlorine into the streets, waterways and nasal passages of an entire country.

Thank you again.


Sebastapol, California

(Where is is warm and sunny)

Gayle writes:

Biology is not my field but upon reading about testing issues perhaps this event could be informative: Evidently the infection was spread within an apartment building in Hong Kong by toilet wastewater vent (someone thought it needed ‘improvement’ and did a bad job). Perhaps the best way to test for infection is by using feces. That is a lot easier to collect from a patient than trying to sample lung mucous.

Sophia writes:

Dear Viral experts

Thank you for helping me keep my sanity these past days!!!!!! I will be eternally grateful for your help. 

I have a couple of picks of the week that I think people might find useful.

1. the WHO free online courses (not as informative as TWIV but quite useful otherwise)


2. the WHO facebook page

They have very useful infographics and had actually a very nice post about receiving packages from China (no virus threat they stated) quite early in the epidemic which I thought was great.

They also had a Q&A on travelling which was quite informative and talked about flying, cruise ships etc. I highly recommend it. Having said that I was quite confused by some of the statements the WHO lady made which I write below in quotes along with my questions. I’d appreciate your take on these:

link for the interview:

Q&A on advice for travellers during 2019-nCoV

Join our Q&A and find out how to protect yourself if travelling during 2019-nCoV. Ask your questions!

Posted by World Health Organization (WHO) on Monday, February 10, 2020

(if you want to check this out these statements they are around 15 mins through the interview)

1-“The virus survives for about 30mins on surfaces.” 

Well, according to the paper on nosocomial pathogens on the last twiv, coronaviruses can stay alive for days. I don’t know where WHO gets their data from. any ideas on this?

2-“There is no such thing as an asymptomatic person. There are always symptoms even if mild…they have sub-clinical symptoms. A person transmits as long as they have symptoms”. well, I am confused now. what do you guys think?

Again thanks for all you do. the latest episodes are the epitome of public service

all the best from Greece

current temp 6 C BUT it is supposed to go up to 17 this week!


ps Can Vincent please make all the books he recommends during the show his picks of the week in the end. Sometimes he talks about a book during the show but by the time twiv ends I no longer remember the title or the author to look it up. thank you

sorry, a couple of more questions as news unfolds this week:

1. WHO is now saying they are trying to contain the virus in its source. I can’t remember if they did that in 2009 as well but is this even realistic? what’s wrong with declaring this another respiratory mild infection that you might get this year? with a fatality rate this low why treat is like Ebola?

2. I am glad you would go to Wuhan. How come everybody else is cancelling events and conferences in the nearby area though? shouldn’t WHO make a statement about safety in conferences?

3. how do you like the new name? I thought it was ok (and useful) to use a name related to the source (Ebola, West Nile, MERS etc). I would have liked to call this the Wuhan virus, how about you?

sorry for all the questions. Many thanks

Sabrina writes:

Hello TWIV team,

I love your podcast and while I have wanted to write in many times, I felt like I had some possibly useful commentary in regards to some discussion at the end of episode 586. You were discussing flu monitoring and reporting in the US tangentially to an email asking if cases of nCoV were possibly/probably being missed in China.

I am a clinical laboratory scientist at a small community hospital in Florida. We run our flu tests via PCR assay and report for Flu A or Flu B. We do not subtype. As I am the lead of my microbiology/serology department, I have to prepare weekly reports for our Infection Control department, which in turn is provided to the DOH. My data is pretty basic, though. Simply number of flu tests performed for the week and how many positives for A and B. Patient samples are kept for 7 days and then discarded, and I have never once been asked to provide samples to the DOH or any other agency for subtyping (again, we are a smaller facility, so this may be part of the reason). We did have a fatality this season that appeared to be possibly flu related……I asked my infection control department how and if we brought that to the attention of the DOH for flu monitoring purposes, and I wasn’t given a clear answer on how that was reported or followed through on. 

All of this is to simply say that I can definitely imagine that the coronavirus numbers are imperfect, because I can see a lot of areas where the way we report flu statistics is open to interpretation and individual hospital’s understanding of how and what to report. 

In response to coronavirus testing of patients: I obviously don’t know how the system works in China – but here, a hospital lab can’t just start running a new test out of the blue. Aside from the test having to actually exist and be manufactured/produced in substantial volume to meet demand, the test has to be approved by the board of directors of the hospital, validated in the lab by running a predetermined number of known positive and negative control sets, SOPs have to be written and implemented, and staff has to be trained on the new assay. We currently have not had any patients tested for the 2019 coronavirus, but we have had a few physicians ask how to go about ordering the test if they wanted it. At this time a sample would have to go to a state reference lab for testing. 

I am trying to picture how this would play out at a facility similar to mine in size and scope in China during an outbreak and it is not hard to understand how the system could become overwhelmed quite easily. 

As we are in Flu season, our little lab is already stretched thin and very busy this time of year. We would be very hard-pressed to rapidly on-board a new test and deal with the added volume that would result from an outbreak such as the one currently going on in China. So my heart definitely goes out to the boots-on-the-ground at the clinical labs in China right now and to the people trying very hard to gather correct and useful data that will paint a workable picture of what is happening with this virus, because I know that when we are looking at the overall numbers and the cumulative data sets, it is sometimes easy to forget all the moving pieces that contribute to bringing all of that information together. 

Thank you for letting me ramble and for your brilliant approach to communicating science!

Warmest regards,


Poppy writes:

Dear respected TWIV team,

My first time writing, long time listener and learner. I used to listen to TWIP TWIV and TWIM in  the garden as I pulled weeds and trim shrubs in the summer; now I listen while I’m cooking in the winter. 

I’ll cut to the chase to save time:     My question is: if the coronavirus makes us human this sick and dying, does it also make the bats sick and dying?  Would one find a ton of dead bat all over the place? 

And could you address the changing of the method of counting the sick, which made the number of the sick jump dramatically on the night of 2/12/20 from 45,202 in the morning [around 8 am CST] to 60,328 at 8 pm CST, if you have any information on it?   I just read the news, and you know how it is – don’t know who one can trust any more.

Thank you especially to Vincent who got these podcasts going to educate the public like me,


Jen writes:

Thanks for your very informative podcast, I recently discovered it due to COVID19 and enjoy it immensely.  

Do we know yet if SARS-CoV-2 is self-limiting? One very concerning rumor is that a Chinese health official was sacked for stating that it is not self-limiting. The official in question (Lan Zhi, the director of the Office of the Municipal Health and Health Committee)  WAS certainly sacked for ‘sending false information’, the only question is what kind of ‘false information’ was he sacked over? Due to the CCP’s treatment of other whistleblower health professionals, it’s hard to trust that this was an justified termination. See here for details: http://archive.li/9p1Yy and here for an article about the termination https://china.huanqiu.com/article/9CaKrnKpjDM.

Rumors aside, how possible is it that SARS-CoV-2 is not self-limiting but rather can cause a persistent/permanent/recurring infection? A read of this paper turns up no similarities to other persistent viruses to my relatively uneducated eye: https://jvi.asm.org/content/84/9/4116 When might we know for sure? 

Speaking of the lack of education: what’s a good intro to virology textbook for someone unable to pursue further higher education but who has undergraduate degree in biochemistry, interest and spare time? Are there any open courseware courses you would suggest? 

As for the local conditions here in Copenhagen, Denmark it’s an unusually bright and sunny day, with temperatures in the 5C range. FWIW it feels like it’s been 5C all winter long this year (but it’s almost always gray and overcast!).

Thanks so much for all of your work, 


Stuart writes:

Hi guys,

Great pod as ever this week – thanks for TWIV and all the other TWIs.

Question on potentially slowing the spread. You told us the entry point for the virus is the human membrane-associated ACE2 receptor. We have dozens of ACE inhibitor drugs available – initially developed to treat high blood pressure. Could we not provide ACE inhibitors to people exposed to 2019-nCoV carriers, and see if that reduces transmission? It is probably no use for treatment of infected subjects, but by blocking ACE2, could it reduce infection rate in newly exposed people?

Here’s a link to the Mayo clinic page on ACE inhibitors. https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/in-depth/ace-inhibitors/art-20047480

Would likely be cheaper, and maybe safer, than the antibodies Alan was talking about.

I don’t know if these drugs could be dosed high enough to block sufficient proportion of receptors, or if the side effects outweigh the potential benefit, but surely worth trying? Eg in the folks who have been evacuated from China, and are currently in quarantine… 


From sunny Raleigh NC, 57oF, mostly sunny…..


Glenn writes:

Hi All,

Im an ex pat NY’R  (now in Wisconsin) and started following you, Vincent, back in the good ole Swine Flu daze….effectively starting my fall down the addicting virology rabbit hole…as a layperson….

These twiv episodes are like pure uncut ____ (enter your chemical vice) to an addict….Thank You! Thank You very much……!

My question is, having read about coronavirus shedding in feces of the Washington patient, and having read about the SARS incident in China where a large communal cluster occurred in an apartment complex (?)….suspecting this vector, 

how likely or plausible is the spread in these “markets” by this means where ALL MANNER of wild critters “leave their mark” and everyone, venders and customers alike, 

walk in and out….and handle goods, etc…..

and how does the virus actually infect the AT2 cells (ACE2 receptors) in the intestinal (small) mucosa ? Does one need to ingest the virus as in contaminated food ? is it coughed up and swallowed from the respiratory tract….Is it simply a matter of mucus flow …? I don’t recall if there was serological testing…Why would only 20% exhibit intestinal compromise…?


I hope that’s not too many questions…..🤭

Thanks in advance,


Stacy writes:

Hi TWIV team!

Thank you so much for answering my questions. That was incredibly exciting for me!

I have a 2009 study for you to read about long term lung damage caused by SARS, and two more questions.

Here’s the study:


My questions are:

  1. Is the new COV19 virus showing the same level of lung damage in patients who have recovered?
  2. Does smoking cigarettes increase the severity of coronaviruses in general?

My concern is that China is going to have an enormous number of citizens with impaired lung capacity, which will put further pressure on its health care system over the years.

I’m in Ottawa and the temperature is a bizarrely warm 0.9 Celsius with light snow making everything look like a Hallmark card. Winters seem more unpredictable these days. It used to get cold, stay cold and build mountains of snow. Now, the temperature can swing from -22 Celsius to -5 Celsius in hours. It’s truly Climate Weirding up here.

I am firmly on side with keeping conversations a part of each podcast. As a non-scientist, it is a tremendous pleasure to hear the passion that drives your curiosity – and I laugh out loud as often as I gasp in wonder at what you are discussing.

Thank you for trusting that listeners will understand – and care!


Stephen writes:

“Grad students studying disease ecology, Erin and Erin found themselves

disenchanted with the insular world of academia. They wanted a way to

share their love of epidemics and weird medical mysteries with the

world, not just colleagues. Plus, who doesn’t love an excuse to have a

cocktail while chatting about pus and poop?”


St. Louis

Neva writes:


Coronavirus brings China’s surveillance State out of the shadows.


What a world we are creating!

Also, voice to text made ‘coronavirus’ ‘Corona violence’.

Remain calm and keep on TWIVing.

Neva from Buda