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| -Signs, Portents, and the Weather- |
| PNAS Study traces 'A,' 'B,' and 'C' variants (Wuhan, E.Asian and European) of COVID using phylogenetic network analysis |
| 2020-04-28 |
| [Eurek Alert] Researchers from Cambridge, UK, and Germany have reconstructed the early "evolutionary paths" of COVID-19 in humans - as infection spread from Wuhan out to Europe and North America - using genetic network techniques. By analysing the first 160 complete virus genomes to be sequenced from human patients, the scientists have mapped some of the original spread of the new coronavirus through its mutations, which creates different viral lineages. "There are too many rapid mutations to neatly trace a COVID-19 family tree. We used a mathematical network algorithm to visualise all the plausible trees simultaneously," said geneticist Dr Peter Forster, lead author from the University of Cambridge. "These techniques are mostly known for mapping the movements of prehistoric human populations through DNA. We think this is the first time they have been used to trace the infection routes of a coronavirus like COVID-19." The team used data from virus genomes sampled from across the world between 24 December 2019 and 4 March 2020. The research revealed three distinct "variants" of COVID-19, consisting of clusters of closely related lineages, which they label 'A', 'B' and 'C'. Forster and colleagues found that the closest type of COVID-19 to the one discovered in bats - type 'A', the "original human virus genome" - was present in Wuhan, but surprisingly was not the city's predominant virus type. Mutated versions of 'A' were seen in Americans reported to have lived in Wuhan, and a large number of A-type viruses were found in patients from the US and Australia. Wuhan's major virus type, 'B', was prevalent in patients from across East Asia. However, the variant didn't travel much beyond the region without further mutations - implying a "founder event" in Wuhan, or "resistance" against this type of COVID-19 outside East Asia, say researchers. |
| Posted by:Lex |
| #4 We used a mathematical network algorithm to visualise all the plausible trees simultaneously Can't see the random forest for the trees? |
| Posted by: Skidmark 2020-04-28 12:55 |
| #3 April 20 article |
| Posted by: Bobby 2020-04-28 06:43 |
| #2 Sincetoday's PNAS study was conducted, the research team has extended its analysis to 1,001 viral genomes. While yet to be peer-reviewed, Forster says the latest work suggests that the first infection and spread among humans of COVID-19 occurred between mid-September and early December. We've seen the Sep-Dec start time before a the 'Burg, maybe a week or two ago. |
| Posted by: Bobby 2020-04-28 06:40 |
| #1 I'll wait until the tested pool is (substantially) greater than 160. |
| Posted by: g(r)omgoru 2020-04-28 03:26 |