Genome sequencing of the strain of the coronavirus which caused the new COVID-19 outbreak in Beijing at the Xinfadi wholesale food market shows it originated from Europe, an expert from Beijing Center for Diseases Prevention and Control (Beijing CDC) said Sunday.
Yang Peng, a researcher from Beijing CDC told China's Central Television (CCTV) via telephone interview that it has been preliminarily determined that the virus found on the samples from the market is related to strains China has seen from imported cases. Genome sequencing showed that the coronavirus came from Europe.
Yang said that the source of the virus is still being traced and it is not known how it entered the market.
There are two main theories as to how the virus got into the market. One is through contaminated seafood and meat imported from abroad which infected those who came into contact with it, Yang said.
The other is through people coming into the market and spread through human secretions such as coughs and sneezes which could also have transferred the virus onto seafood or meat.
Yang said Beijing CDC will now conduct an epidemiological investigation into early and key cases, and will also conduct more tests on the strain of virus found in the Xinfadi cluster.
Beijing's Fengtai district will conduct nucleic acid tests on more than 46,000 residents living in communities near the Xinfadi market, where a total of 51 confirmed cases in the capital city were traced to, government officials said.
The district has set up 24 nucleic acid testing stations. Currently, 10,881 residents have been tested, district authorities said.
Zhang Jie, a vice head of Fengtai district government, said that 8,186 throat swab samples have been collected from people related to the Xinfadi market and 5,803 samples were tested, all coming back negative.
As of Sunday afternoon, authorities said that 394 close contacts related to the Xinfadi market had been tracked, 242 of whom are from Fengtai district. At present, 111 people are quarantined in designated places, and the rest are in isolation at home.