Interpretation News|What does it mean that 29 samples were mixed positive for the first round of nucleic acid tests for all employees in Xiamen?

  The scope of the local epidemic in Xiamen, Fujian, has expanded further.

  On September 14, Xiamen City, Fujian Province launched a nucleic acid test for all employees.

On September 17, Xiamen completed the first round of nucleic acid testing for all employees, and 29 samples of 10 mixed 1 positive were found.

  In this round of the local new crown epidemic in Xiamen, the first case was found to have infected 32 people. Xiamen initiated a nucleic acid test for all employees. What was the reason?

What does it mean that 29 samples of 10 mixed 1 positive samples were detected in the first round of nucleic acid testing?

How about Xiamen's nucleic acid testing capabilities?

How many rounds of nucleic acid for all employees?

The Paper has sorted out these issues.

Why start the nucleic acid test for all employees?

  The first case of this round of the epidemic in Xiamen was discovered on September 12. Tong'an District of Xiamen City screened people who came to Xiamen from medium and high-risk areas such as Fengting Town, Xianyou County, Putian City, and found a new crown of Wu Moumou who came to Xiamen. Viral nucleic acid test was positive.

After verification, Wu Moumou was a close contact of the reported case Wang Moumou in Putian City.

  On September 14, when Xiamen decided to start the first round of nucleic acid testing for all employees, the number of infections associated with the first confirmed case of Wu Moum increased to 32.

  Why is the nucleic acid test for all employees in Xiamen launched at this time?

At the press conference of the State Council’s Joint Prevention and Control Mechanism on September 16, Wang Huaqing, chief expert on the immunization program of the China Centers for Disease Control and Prevention, explained that if the epidemic is discovered late or the epidemiological investigation cannot determine the scope of the epidemic, screening at this time The scope and the screening population may need to be further expanded, requiring full screening in order to find the source of infection as soon as possible and take corresponding measures to stop the spread of the epidemic.

  Epidemiological investigations have not yet been able to determine the scope of the infection. The most direct case is that when investigating infection cases, some people cannot determine how the infection was caused.

On September 15th, a news was disclosed at a press conference on the prevention and control of the epidemic situation in Xiamen. The strain infected by Cai Moumou, an outsourced service staff member of the First Affiliated Hospital of Xiamen University (confirmed case 12), was sequenced and compared with that of the city’s leader. The virus genes of the confirmed cases of Wu XX are highly homologous.

  The outsourced service staff of the First Affiliated Hospital of Xiamen University are in Siming District, Xiamen, but the cluster infections caused by Wu Moumou mainly occurred in Tong'an District, Xiamen.

The two districts are located in Xiamen City, one south and one north. How the cases are related, the official circulation information has not been released.

How is Xiamen's nucleic acid testing capabilities?

  On September 17, at the Xiamen Municipal Government’s press conference on epidemic prevention and control, the municipal headquarters has decided to initiate the second round of nucleic acid testing for all employees.

  According to the latest population data released by the Xiamen Municipal People's Government, Xiamen has a permanent population of 4.29 million in 2019.

Nucleic acid testing for more than four million people is not easy, not only requires a large number of sampling personnel, but also needs to keep up with laboratory testing capabilities.

  The Paper's inquiries on the Mini Program Mini Program of the State Council Client show that there are 35 nucleic acid testing institutions in Xiamen.

  What is the current testing capacity of Xiamen Nucleic Acid Testing Agency?

On the evening of September 17, Zhang Yanggen, the head of the Xiamen Inspection Medical Laboratory, a third-party testing agency, told The Paper that after the current round of Xiamen's new crown epidemic, the workload of their laboratory has doubled.

  "We have more than 10 employees working overtime to perform tests in the laboratory. They can only sleep for one or two hours a day. We must strive to provide accurate test results within 24 hours." Zhang Yanggen said, in order to deal with the next second round Nucleic acid testing of all employees, their laboratory is adding professional equipment and personnel to increase the amount of testing, which can achieve more than 8,000 tubes per day.

  At the press conference on the prevention and control of the epidemic situation in Xiamen on September 16, Liao Huasheng, the deputy mayor of Xiamen, introduced that Xiamen has now settled 4 large shelter laboratories in the Xiamen International Convention and Exhibition Center and the Jiageng Stadium, which will greatly increase the city’s new crown. Viral nucleic acid detection capability.

What does the 29 10 mixed 1 positive samples mean?

  In full-staff nucleic acid testing, in order to improve testing efficiency and save costs, mixed sampling methods are usually adopted.

Xiao Meng, assistant to the director of the Department of Laboratory Medicine of Peking Union Medical College Hospital, explained in an interview with The Paper that 10 mixed 1 refers to a group of 10 people when sampling, and the throat swabs or nasal swabs of 10 people are put into a sample preservation solution. .

  On September 17, the Xiamen Municipal Government held a press conference on epidemic prevention and control, stating that in the first round of nucleic acid testing, a total of 29 10-mix-1 positive samples were detected, from 1 in Siming District, 1 in Huli District, and Tong'an District. 27 copies.

  The 29 10 mixed 1 positive samples involved 290 people, but it does not mean that these 290 people are all infected. In a group of 10 people, as long as there is one infected person, this sample will be positive.

Twenty-nine 10 mixed 1 positive samples mean that at least 29 people have been infected with the new coronavirus.

The Xiamen epidemic has affected Tongan District, Siming District, Huli District, Haicang District and other places.

When will the full-staff nucleic acid test end?

  When will the full-staff nucleic acid test start and end?

Although each round of the local epidemic is different, some experience can be drawn from previous prevention and control.

The Paper reviewed the progress of nucleic acid testing for all employees previously announced by Yangzhou. According to Yangzhou's previous experience, after 7 rounds of nucleic acid testing for all employees, nucleic acid testing for key personnel was started.

  After the first and second rounds of nucleic acid testing for all employees in the main urban area of ​​Yangzhou, a total of more than 3.2 million nucleic acid sampling tests were completed, and 26 positive infections were found.

In the third round of screening, 13 people were positively infected.

Until the seventh round, 4 cases were positive.

Yangzhou began to change its strategy and launched a large-scale nucleic acid test in key areas of the main urban area.

Since then, there have been sporadic cases of nucleic acid testing in key areas, but they are all in single digits.

  Yangzhou’s experience sums up a principle: After completing 7 rounds of full-staff nucleic acid testing, the streets (townships) where cases have appeared in rounds 5-7 shall be tested once a day; if cases only appear in rounds 1-4, 3 days 1 Times; if there is no case, once every 5 days.

Then, according to the situation of the cases found in the screening and their action trajectory, dynamic adjustments are made to optimize the detection strategy.

  The Paper Journalist Hu Danping

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