China News Service, July 10th, 10th, the Chinese Center for Disease Control and Prevention announced on the official website the progress of the new coronavirus pneumonia epidemic in Beijing from June to July 2020 (2). It is pointed out that Beijing has passed 22 days since the Xinfadi wholesale market was closed on June 13 and is close to the two longest incubation periods. The risk of continued exposure of the relevant exposed personnel has been basically eliminated. At present, the number of new cases per day in Beijing has been in single digits for one week in a row, and all come from the effectively managed population. The risk of subsequent new infections is low, and the Beijing epidemic has been effectively controlled.
Data map: On June 17, the inspectors of key areas and key populations in the Xinfadi market in Beijing received nucleic acid detection of the new coronary pneumonia virus at Fangzhuang Sports Park in Fengtai District. Photo by Jia Tianyong, reporter from China News Service
On June 11, a new coronavirus pneumonia epidemic related to the wholesale market of agricultural products in the new development area occurred in Beijing. As of 24:00 on July 6, 400 cases of this new coronary pneumonia outbreak were reported (including 362 confirmed cases and 38 asymptomatic infections). The epidemic affected 7 provinces and cities, of which 366 cases were reported in Beijing (335 confirmed cases, 31 asymptomatic infections), 27 cases in Hebei (21 confirmed cases, 6 asymptomatic infections), and 3 cases in Liaoning (3 confirmed cases), 1 case in Sichuan (confirmed case), 1 case in Tianjin (confirmed case), 1 case in Zhejiang (confirmed case), 1 case in Henan (infected person without symptoms).
Regarding the test results of the case samples, the CDC's whole-genome high-throughput sequencing results of 52 confirmed case samples from Beijing showed that, compared with the Wuhan reference strain NC_045512 sequence, all samples were in C241T, C3037T, C14408T, A23403G was mutated at four sites, and GGG mutation to AAC occurred at sites 28881-28883, which was consistent with the mutation characteristics of the I gene locus in the branch of the European family of L genotype. The high-throughput genome-wide sequence of the new coronavirus from confirmed cases in Hebei and Tianjin is 100% identical to the genome-wide sequence of the case samples from Beijing, and there are corresponding mutation sites. They also belong to the European family branch I of the new coronavirus L genotype.
Regarding the detection results of environmental samples, the CDC conducted a high-throughput sequence analysis of the whole genome of the new coronavirus on 8 environmental samples from the Xinfadi market in Beijing. , C14408T, A23403G, GGG28881-28883AAC mutations at the seven sites are the same and belong to branch I of the European family of L genotype.
Talking about the characteristics and trends of the epidemic, the Chinese Center for Disease Control initially determined that the clustered new coronary pneumonia epidemic in Beijing’s new development market was caused by a large-scale exposure through various exposure methods such as pollution of the environment, objects, and personnel contact. Outbreak. The epidemic quickly spread to multiple districts and other provinces in Beijing, and 29 new epidemic-related epidemic outbreaks occurred in relevant markets, households, and units.
According to the epidemiological investigation and analysis of viral gene sequencing results, the strain causing the outbreak is the European genotype I of the L genotype, which excludes the possibility of the outbreak caused by animal virus spillage infecting people. How the virus is introduced into the market and the mechanism of its spread and spread in the market is under further investigation.
According to the China Center for Disease Control and Prevention, the effects of comprehensive prevention and control measures implemented in Beijing and other regions have already appeared. Since the closure of the Xinfadi wholesale market on June 13, 22 days have passed, and the two longest incubation periods have been approached. The risk of continued exposure of the exposed personnel has been basically eliminated. High-risk environments and people have been effectively identified, detected, and included in the scope of management and control. At present, the number of new cases per day has been in single digits for one week in a row, and all come from the effectively managed population. The risk of subsequent new infections is low, and the Beijing epidemic has been effectively controlled. Hebei, Liaoning, Henan, Zhejiang, Sichuan and Tianjin have all effectively controlled the epidemic situation in the new places of Beijing.