Trevor Bedford

According to this estimate[0] based on viral mutations, there were 600 cases in Seattle on March 4th. That puts the multiplier at about 20x cases per confirmed case. With an estimated doubling time of 7 days[1], that's about one month worth of spreading. (Disclaimer: all numbers approximate, high uncertainty everywhere.) [0] https://bedford.io/blog/ncov-cryptic-transmission/ [1] https://bedford.io/projects/ncov-phylodynamics/

In Seattle, the best current estimate (https://bedford.io/blog/ncov-cryptic-transmission/) is 570 infections as of March 2: > Knowing that transmission was initiated on Jan 15 allows us to estimate the total number of infections that exist in this cluster today. Our preliminary analysis puts this at 570 with an 90% uncertainty interval of between 80 and 1500 infections.

For the most part, I think we should trust people's instinct to secure resources for themselves in expectation of upcoming hard times. I live in Seattle. Due to the minimal testing that has occurred, we are just now learning of multiple cases which are being retroactively classified as Covid-19. These are from the very few that have actually been tested, which is a small proportion of those who showed severe enough symptoms to warrant testing. Genomic analysis suggests that the virus has been spreading undetected in the community since January 15th https://bedford.io/blog/ncov-cryptic-transmission/ This is from a virologist at Fred Hutch Cancer Institute who is part of a viral epidemiology study. If the virus doubles every 6 or 7 days as estimated, then... well, you're all good with your powers of 2, there are likely hundreds of cases already. Every day there are new announcements of deaths from this disease just miles away, of new people showing symptoms, of people whose "flu" has been diagnosed after the fact as coronavirus. In a dense urban center like this with people crowded together on streets, in buses, in workplaces, I am working under the assumption that it is already in my neighborhood. I don't think that's unreasonable. The pharmacies in the area have been filling people's prescriptions for three months' worth without any prompting. They are planning for a long slog in which they want to keep people AWAY from the pharmacy as much as possible. The county has…

Covid-19 mutates about 2x a month. https://bedford.io/blog/ncov-cryptic-transmission/ This doesn't mean the virus has changed enough for your body to not recognize it. But it can be used to map transmission chains. We know where Covid-19 started, but scientists have also used mutation rates to correct our understanding of when HIV jumped to humans.

Here's a genetic analysis that was widely shared last month, which points to an index patient in late November around Wuhan: https://bedford.io/blog/ncov-cryptic-transmission/ Here's an article from Feb 11th in the SCMP which notes 500 health care workers in Wuhan were infected with the virus: https://www.scmp.com/news/china/society/article/3050077/least-500-wuha…

Its only been around a few months so hasn't had a chance to significantly mutate- and it hasn't needed to. As such its unlikely you'll get a second time any time soon, however in future years it could mutate. Here is an article on how they can see the DNA changing in different patients so can track the path of infections. https://bedford.io/blog/ncov-cryptic-transmission/

The current rate of estimated infection doubling from genomic analysis is 7 days, absent containment measures and other interventions. Assume there are 1000 cases today and do the math. You get there pretty quick: https://bedford.io/blog/ncov-cryptic-transmission/

https://bedford.io/blog/ncov-cryptic-transmission/ - For anyone looking for more info around how the transmission/mutation works. Quick read.

> This sounds like pure speculation and is probably not a reasonable thing to assume. It is speculation, but not pure speculation - there is some data to back it up. Trevor Bedford [0] is a researcher at Fred Hutch in Seattle and a professor at UW, focusing on genomic sequencing of viruses. He estimated two days ago [1] that the number of cases was in the hundreds, with a large degree of uncertainty: > This approach leads to a similar estimate of the number of current infections at 330 with a 90% uncertainty interval of between 20 and 1500 infections. This is solely an estimate of the infections here in the Seattle area, based on gene sequencing. 0: https://bedford.io/team/trevor-bedford/ 1: https://twitter.com/trvrb/status/1234589820946534401

For evidence about debunking, you can check out Twitter threads from Trevor Bedford (bio: https://bedford.io/team/trevor-bedford/) that are linked from https://twitter.com/trvrb/status/1339266367522918400 In this discussion and the older threads he links in there, Bedford basically rules out an 'engineered' virus, does not rule out a lab leak, but leans towards zoonosis (pathogen jumping from animal to human). - Here are Thread reader links for the older threads he references: Were parts of HIV inserted into SARS-CoV-2? https://threadreaderapp.com/thread/1223666856923291648.html What do the number of amino acid and nucleotide changes tell us? https://threadreaderapp.com/thread/1224207086013149184.html Which data point are consistent with zoonosis or lab escape? https://threadreaderapp.com/thread/1230634136102064128.html