Release of traceability of local cases in Haidian, Beijing The case has been exposed to Canadian international mail

On January 17, the 267th press conference on the prevention and control of the new crown pneumonia epidemic in Beijing was held. Beijing Youth Daily reporter learned at the meeting that Pang Xinghuo, deputy director of the Beijing Municipal Center for Disease Control and Prevention, reported on the traceability of the confirmed cases of new crown pneumonia in Haidian District of the city. On January 15, the city reported a confirmed case of local covid-19. As of now, there have been no new indigenous cases. After further epidemiological investigation and a full range of risk point screening, sampling testing, positive cargo screening and gene sequencing, progress has been made in tracing.

First, there was no history of travel in other provinces and cities in the 14 days before the onset of the case, and international mail was occasionally sent and received during the work. The case developed itchy throat symptoms on January 13, fatigue and fever on January 14, no typical manifestations of new coronary pneumonia in lung CT on January 15, and the change in the nucleic acid detection CT value of the case specimens on January 14, 15 and 16, combined with clinical manifestations and test results, it was preliminarily judged that the case was in the early stage of infection.

Second, through epidemiological investigation and big data comparison, no trajectory overlap was found through the investigation of the history of contact between cases and various risk groups, including inbound personnel, people from risk areas outside Beijing, cases and close contacts.

Third, through the investigation of the activity trajectory of the case in the 14 days before the onset of the disease, a total of 18 public risk points were screened, and the source of infection, close contacts, and high-risk groups were checked synchronously according to the risk points. At present, 69 close contacts have been determined, all of which have been controlled in place, and the nucleic acid test results are negative. 16,547 specimens of various types of risk personnel were collected. Up to now, the specimens of the personnel living with and working with the case are negative; the specimens of other types of risk personnel are negative; a total of 811 external environmental samples, except for the positive environment outside the family and work unit of the case, the rest of the environmental specimens outside the risk point are negative.

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

Fifth, the case reported that he had recently sent and received international mail. We conducted a thorough investigation, sampling and testing. The international mail was sent from Canada on 7 January, via the United States and Hong Kong, China, to Beijing, and the case received the mail on 11 January. The case is self-reported, during which time it only touched the outer surface of the mail package and the first page of the document paper, and did not touch the inner surface of the package and other papers. 22 environmental specimens of the international mail have been collected, including 2 on the outer surface of the package, 2 on the inner surface and 8 specimens on paper in the document, all of which were positive for nucleic acid testing, and the specific mutation sites of the Omikerong strain were detected. Up to now, a total of 8 people may be contacted during transportation, and the nucleic acid test results of the remaining contacts except for the cases are negative. In addition, 54 environmental specimens of international mail sent from the same source to another location that had not yet been unopened were collected and 5 positives were detected, including 1 positive for outer packaging and 4 positive for paper inside the document.

Sixth, the laboratory of the Municipal Center for Disease Control and Prevention performed whole genome sequencing of case specimens, and gene sequence analysis showed that the virus belonged to the VOC/Omicron variant (BA.1 evolutionary branch). There are differences with previous cases in Beijing and recently reported by provinces (cities) at home and abroad, and they do not belong to the same chain of transmission, and the similarity is high with some strains isolated in North America and Singapore in December 2021.

In summary, combined with the epidemiological history of the case, the test results of the suspicious item sample and the genetic sequencing results of the case specimen, it is not excluded that it may be infected with the virus through the foreign article.

Text/Beijing Youth Daily reporter Jiang Ruojing Wu Wenjuan Li Zewei

Editor/Gao Yan