Study finds: nucleic acid in patients with asymptomatic infection becomes negative again after many days

Home Health Study finds: nucleic acid in patients with asymptomatic infection becomes negative again after many days

Original title: The study found that the nucleic acid of patients with asymptomatic infection turned positive again after many days.

After the detection of nucleic acid of patients with asymptomatic infection of neocoronavirus, the possibility of “rejuvenation” again.

The surging news noted that in recent days, a study analyzed 14 asymptomatic infections found in Yangzhou from January 21st to February 29th. The study found that there was one case of asymptomatic infection in the city that was positive for the first nucleic acid test, and the nucleic acid test was negative for three consecutive times on days 9, 15, and 17, and again positive on day 28.

According to the research, if conditions permit, the close contacts of confirmed cases and asymptomatic infected persons should be taken for centralized medical observation, and timely sampling and testing should be conducted to find possible sources of infection as soon as possible. At the same time, after the asymptomatic infection is lifted from medical observation, health monitoring needs to be carried out for 2-4 weeks to prevent nucleic acid detection from becoming a new source of infection after Fuyang.

The above study is entitled “Characteristic Analysis of Asymptomatic Infections of New Coronavirus Pneumonia in Yangzhou City, Jiangsu Province”. The authors are Li Jincheng, Xu Qin, et al from Yangzhou Centers for Disease Control and Prevention. It was published in the Journal of Practical Clinical Medicine on March 18.

According to the study, from January 21 to February 29, Yangzhou reported a total of 16 cases of asymptomatic infection of new coronary pneumonia, of which 2 cases were confirmed cases. Two confirmed cases were excluded, and 14 were asymptomatic, of which 7 were male and 7 female, the youngest was 8 months old, the oldest was 73 years old, and the average age was 38.7 years old.

In terms of exposure, out of 14 asymptomatic infections, 13 were close contacts of confirmed cases, and one exposure history could not be clearly confirmed. The husband of the asymptomatic infected person whose exposure history is not clear has a history of contact with the confirmed case, but his husband’s throat swab and anal swab specimens were collected several times, and the nucleic acid test was negative. Positive for IgG and suspected asymptomatic infection.

The study pointed out that the above 14 cases of asymptomatic infection were found through confirmed cases, clustered cases, follow-up investigation of source of infection, and examination of close contacts. Among them, 13 cases were collected for the first time, and the nucleic acid test was positive. One case was positive for single target. After 2 days, the throat swab sample was collected again, and the nucleic acid test was positive.

In this group of patients, the longest exposure to a positive nucleic acid test for asymptomatic infection was 19 days, with an average time of 13.8 days; the time for a negative swab nucleic acid test to turn negative was 8-21 days, with an average of 10.9 days; An 8-month-old infant had a positive nucleic acid test for 21 days.

It is worth noting that the study found that as of February 29, 13 of the 14 asymptomatic infections had negative nucleic acid tests in the throat swab specimens; 1 had a positive nucleic acid test in the first throat swab specimens. The nucleic acid test of the throat swab specimen was negative 3 times in 17 days, and the nucleic acid test of the throat swab specimen was positive on the 28th day.

The study believes that timely detection of confirmed cases and asymptomatic infections, and tracking and screening of close contacts can detect asymptomatic infections in the shortest time. Because there is a certain percentage of asymptomatic infections, and this part of the population can also be the source of infection, screening and management of confirmed cases and close contacts of asymptomatic infections based on the presence or absence of clinical symptoms cannot achieve the purpose of isolating the source of infection. Close contacts of confirmed cases and those with asymptomatic infections should be investigated while sampling, early detection, timely detection and control of the source of infection to prevent asymptomatic infections in the detoxification period.

Regarding the above three consecutive cases of negative nucleic acid tests and then finding positive cases, the study emphasized that asymptomatic infections should still take home isolation measures after lifting professional medical observations. With reference to the management measures after discharge of confirmed cases, follow-up visits were performed at 2 and 4 weeks after professional medical observation was lifted, and throat swab specimens were collected for nucleic acid testing. Carrying out physical health monitoring and testing of serum-specific antibodies IgM and IgG at the same time to prevent asymptomatic infections of throat swab nucleic acid test from re-yang becoming a new source of infection.

At present, the central government has put forward further requirements for the prevention and control of asymptomatic infection.

According to the Chinese government website, on March 30, Li Keqiang, member of the Standing Committee of the Political Bureau of the Communist Party of China Central Committee, Premier of the State Council, and leader of the Central Leadership Group for New Pneumonia Epidemic Situation, chaired a meeting of the Leadership Group.

The meeting pointed out that to consolidate the results of epidemic prevention and control and prevent loopholes in prevention and control, it is necessary to highlight the monitoring, tracking, isolation and treatment of asymptomatic infection. It is necessary to increase the screening of asymptomatic infections in a targeted manner, and further expand the scope of detection to new coronary pneumonia cases and close contacts of those who have found asymptomatic infections, as well as key areas and populations with special requirements. Once asymptomatic infection is found, it is necessary to strictly follow the “Four Morning” requirements, strictly centralized isolation and medical management, openly and transparently release information, resolutely prevent late reporting and underreporting, identify the source as soon as possible, and implement isolation medical observation for close contacts. . Quickly take a certain percentage of samples in key epidemic areas, conduct investigations and epidemiological analysis of asymptomatic infections, and study and improve prevention and control measures. At the same time, do a good job of reviewing the patients after discharge and strengthen the medical management of Fuyang personnel.

On the afternoon of March 31, Chang Jile, director of the CDC of the National Health and Medical Commission, said at a press conference of the State Council Information Office that starting from April 1, the National Health and Medical Commission will announce the number of asymptomatic infections in the daily epidemic notification. Report, report and manage the situation and respond to social concerns in a timely manner.

Editor-in-chief: Fan Stern