Health Times reporter Wang Zhenya
Since December 9, as of 00:00 on December 26, Shaanxi Province has reported a total of 499 locally confirmed cases, including 485 cases in Xi'an City, 7 cases in Yan'an City, and 7 cases in Xianyang City. From the perspective of transmission trajectory, the family hospital of Chang'an University has become a major spread point of the current round of epidemic in Shaanxi, with at least 50 confirmed cases.
How to find the source of infection of the epidemic in Shaanxi? The date of the first confirmed case of the family hospital of Chang'an University is December 15, from December 9 to December 15, the first case in Shaanxi to the large-scale spread of the family hospital of The headquarters of Chang'an University, in one week, how does the virus spread?
Cartoon diagram of the epidemic transmission chain in Xi'an City. The picture is according to the WeChat public account of the Institute of Public Health and Health of Nankai University
According to the deputy director of the Xi'an Municipal Health Commission, before the large-scale screening of key populations, the virus has been quietly spreading for a period of time, and there has been a multi-point hidden transmission.
The breakthrough point in the traceability of the source of infection occurred on 2 asymptomatic infected people identified in Dongguan City on December 13. The two patients took a flight from Xi'an Xianyang International Airport to Shenzhen on December 4 and returned to Dongguan City from Shenzhen on December 5 (there is a spatio-temporal intersection with the xi'an confirmed case), so Xi'an Xianyang International Airport has become the focus of this traceability.
According to the investigation, the first confirmed case in Xi'an on December 9 was a person who delivered meals to people imported from overseas for quarantine. The flight PK854, which entered from Pakistan to Xi'an Xianyang International Airport on December 4, has detected confirmed cases on the same day, and as of December 23, the flight has detected 6 confirmed cases.
Moreover, the first confirmed patient in the Family Hospital of Chang'an University headquarters was sent to Xi'an Xianyang Airport on the afternoon of December 4, and stopped at Terminal 3, check-in desk and parking lot. The three keywords of "December 4, airport, and contact with imported cases from abroad" have become the common points of two cases in Dongguan, the first confirmed case in Xi'an, and the first confirmed case in the family hospital of Chang'an University.
According to the Shaanxi Provincial Health Commission, the Shaanxi Provincial Center for Disease Control and Prevention has performed whole genome sequencing of 36 indigenous case specimens, all of which are Delta variants, and are highly homologous to the imported cases found in passengers from Pakistan on December 4, PK854.
In the end, the source of the current round of epidemic transmission in Shaanxi was found, and it was a confirmed case of a flight imported from abroad. On the afternoon of December 18, a press conference on the prevention and control of the new crown pneumonia epidemic in Shaanxi Province was announced, combined with the circulation information, it was determined that this was a local epidemic caused by overseas imported flights, and the transmission chain was continuously extended through family and community transmission.
