The traceability results of new cases in Beijing announced on the 15th are highly similar to the North American and Singapore strains – Xinhua English.news.cn

This morning, Beijing held the 267th press conference on the prevention and control of the new crown pneumonia epidemic. At the press conference, Pang Xinghuo, deputy director of the Beijing Center for Disease Control and Prevention, informed that on January 15, Beijing reported a confirmed case of local new coronary pneumonia. So far, there have been no new local cases. After further epidemiological investigation and comprehensive risk point investigation, sampling test, positive cargo investigation and gene sequencing, the traceability situation has made progress.

First, there is no history of travel and residence in other provinces and cities within 14 days before the onset of the case, and international mails are occasionally sent and received during work. The case developed symptoms of itchy throat on January 13, fatigue and fever on January 14, and no typical manifestations of new coronary pneumonia were found on lung CT on January 15. The nucleic acid of the case specimens on January 14, 15, and 16 was combined. Changes in CT values ​​were detected, combined with clinical manifestations and test results, to preliminarily judge that the case was in the early stage of infection.

Second, through epidemiological investigation and big data comparison, through the investigation of the contact history of cases and various risk groups, including those entering the country, people coming to Beijing from risk areas outside Beijing, cases and close contacts, no trace overlap was found.

The third is to investigate the activity trajectories of the cases in the 14 days before the onset of the disease, and investigate a total of 18 public risk points. At present, 69 close contacts have been determined, all of them have been placed under control, and the nucleic acid test results are all negative. A total of 16,547 specimens of persons with various risks were collected. Up to now, the specimens of the people who lived and worked with the case were all negative; the specimens of other types of risk persons were all negative; a total of 811 samples were taken from the external environment. Environmental specimens outside the site were all negative.

The fourth is to investigate the cold chain contact history of the cases, and the relevant cold chain test results are all negative.

Fifth, the case self-reported that he had recently sent and received international emails. We conducted a comprehensive investigation, sampling and testing for this. The international mail was sent from Canada on January 7 and arrived in Beijing via the United States and Hong Kong, China, and the case received the mail on January 11. The case reported that during this period, it only touched the outer surface of the mail package and the front page of the document paper, and did not touch the inner surface of the package and other papers. 22 environmental samples of the international mail have been collected, including 2 on the outer surface of the package, 2 on the inner surface and 8 on the paper inside the document. The nucleic acid test was positive, and the specific mutation site of the Omicron variant was detected. . Up to now, there are 8 people who may have been in contact with them during transportation. Except for the case, the nucleic acid test results of the other contacts are all negative. In addition, 54 environmental samples of international mails from the same source and sent to another location that have not been opened were collected, and 5 were found to be positive, including 1 positive for the outer packaging and 4 positive for the paper in the document.

Sixth, the laboratory of the Municipal Center for Disease Control and Prevention conducted whole-genome sequencing of the case specimens. Gene sequence analysis showed that the virus belongs to the VOC/Omicron variant (BA.1 evolutionary branch). There are differences with the previous cases in Beijing and the Omicron variant strains reported by domestic and foreign provinces (cities) recently, and they do not belong to the same transmission chain; they are highly similar to some strains isolated in North America and Singapore in December 2021.

To sum up, combined with the epidemiological history of the case, the test results of suspicious items, and the gene sequencing results of the case specimens, the possibility of contracting the virus through foreign items cannot be ruled out.

(Headquarters reporter Ji Lele and Fu Hailiang)