What’s new: Researchers at Harvard University have published a preprint paper concluding that the coronaviruses causing Beijing’s new Covid-19 outbreak genetically resemble those in both southern Asia and Europe.
The findings suggest that the virus emerged in China in March and was then “reintroduced” into the country from South and Southeast Asia sometime in April and June.
The study was posted on BioRxiv, a preprint server for biology research. Preprint papers have not undergone a peer review process attesting to their credibility.
The researchers used machine learning to sort 7,643 genomes of SARS-CoV-2, the virus that causes Covid-19. They then compared the genomes of viruses in other parts of the world with human and environmental samples taken from the Beijing outbreak.
The background: In mid-June, Yang Peng, an expert at the Beijing Center for Disease Prevention and Control (CDC), said the city’s new cases, most of which have direct ties to a wholesale food market, appeared to be caused by a “European” virus strain.
According to a report published June 19 on the official WeChat public account of the Central Committee for Discipline Inspection, the Party’s internal watchdog, the China CDC had concluded virus samples collected at the site were older than the strains then circulating in Europe, suggesting that the pathogens could have lain dormant in the market and evolved slowly.
Beijing recorded 331 new Covid-19 infections between June 11 and Thursday, according to the municipal health commission.
Contact reporter Matthew Walsh (matthewwalsh@caixin.com) and editor Marcus Ryder (marcusryder@caixin.com)
