Quick thread on the heels of my piece with @sciencecohen pointing out some of the challenges in diagnosing #COVID19 #2019nCov
sciencemag.org/news/2020/02/l…
sciencemag.org/news/2020/02/l…
@sciencecohen @juliaoftoronto Yes, not like we don’t have enough misinformation to contend with already. Don’t really need journals like @NEJM getting in on that particular game. Unnecessarily stubborn. Seems clear to me that given this information they would never have accepted title etc.
@sciencecohen 1. The challenges are very different depending on where you look. Africa is ramping up testing of #2019nCoV #SARSCoV2 now. It’s really about lab capacity there. African CDC has organized a first training in Dakar, kits have been shipped from Germany.
@sciencecohen Some places in China are understandably just overwhelmed by the sheer numbers. In the US it’s partly a matter of CDC having to supply the tests. Good overview of situation in Europe in this paper: eurosurveillance.org/content/10.280… h/t @vmcorman
@sciencecohen @vmcorman 2. What will more testing show? @JeremyFarrar thinks that #2019nCoV #SARSCoV2 is already more or less everywhere. We just haven’t picked it up because it takes time and many infections for severe cases to turn up and we've only looked in people recently returning from China.
@sciencecohen @vmcorman @JeremyFarrar More and more epidemiologists I talk to share that view. If that’s true, expect the tip of the iceberg starting to show itself in the next week or two in the form of severely ill #COVID19 patients turning up in hospitals whether in Africa, Europe or N America.
@sciencecohen @vmcorman @JeremyFarrar This is Farrar: "If you had a sore throat tomorrow with no contact, would you go for testing anywhere? […] We are underestimating how common this infection is.” #COVID19 #SARSCoV2
@sciencecohen @vmcorman @JeremyFarrar 3. Several groups are working on antibody tests. That is important to get a handle on how common this infection really is on a population level, partly because you see who was infected in the past and not just who is infected right now.
@sciencecohen @vmcorman @JeremyFarrar It might also help answer questions like: How long are people protected after an infection? Why are older people at a higher risk? And of course serology can be used to screen animal populations to find reservoir species for #SARSCoV2 #2019nCoV
@sciencecohen @vmcorman @JeremyFarrar 4. Something that didn’t make it into the article: Diagnostics are not just important to find out who is sick. Also interesting questions about deciding when a patient can be safely sent home!
@sciencecohen @vmcorman @JeremyFarrar I talked to Clemens Wendtner, who has been treating some of the German patients. He told me Monday evening that of four #COVID19 patients he had been treating for four weeks, three were still PCR-positive even though based on symptoms they would have been sent home by now.
@sciencecohen @vmcorman @JeremyFarrar Do doctors have to wait til throat swab, stool sample, urine are all negative for #SARSCoV2 RNA? Consensus seems to be emerging that that is not the case. Scientists are monitoring PCR results in tandem with cell culture experiments looking for infectious virus.
@sciencecohen @vmcorman @JeremyFarrar Idea is to define a threshold where PCR may still be positive but there is confidence that no infectious virus being shed. Bear in mind: These are all public health decisions that have to be made with a lot of uncertainty in a rapidly evolving situation.
@sciencecohen @vmcorman @JeremyFarrar Of course, if #COVID19 turns out to really be everywhere already, this becomes an academic question. No use keeping people in isolation in the hospital, when the virus is spreading on the bus and in the office anyway.
@sciencecohen @vmcorman @JeremyFarrar 5. I spend more time these days talking to @sciencecohen in San Diego than with anyone in my own timezone and I find that disconcerting. (I get the feeling his dog is getting jealous of the attention too.)
Sorry made a mistake here! It is 4 patients that have been treated for 2 weeks of course! not 4 weeks!
