(Combating New Crown Pneumonia) Focusing on Asymptomatic Infected Persons: How to Prevent and Control New Crown Virus "Lurker"?
China News Agency, Beijing, March 29th: Focus on asymptomatic infections: how to prevent and control the "latent" of the new crown virus?
Author Zhang Su Guo Chaokai
Ten years ago, China's domestic spy war drama "Hidden" hit the air. Nowadays, New Coronavirus is "latent" in the population, and there have been many "asymptomatic infected persons" who have no clinical symptoms but have positive pathogenic tests for New Coronavirus in respiratory and other specimens. How to effectively prevent and control "latent persons" has attracted much attention.
Will the outbreak be re-emerged due to the "lurker"
Recently, Shandong, Dezhou, Guizhou, Guiyang, Sichuan Mianyang, and other places have reported asymptomatic infections imported from abroad. Jiaxing, Zhejiang has reported locally diagnosed cases associated with asymptomatic infections imported from abroad. Locally diagnosed cases reported by Henan Luohe on the 29th have been associated with asymptomatic The infected people eat together. Zhong Nanshan, academician of the Chinese Academy of Engineering, Zhang Wenhong, senior expert group leader of the Shanghai expert treatment group of New Crown Pneumonia, and Zhou Qi, member of the Chinese Academy of Sciences, all reminded that they should pay close attention to asymptomatic infection.
Experts from Ningbo Centers for Disease Control and Prevention compared the infection rate of close contacts of confirmed cases (6.30%) with that of close contacts of asymptomatic infections (4.11%), and concluded that "the difference in infection rates was not statistically significant" .
"The Ningbo study has certain reference value, but we cannot rush to conclusions." Zeng Guang, chief scientist of epidemiology at the Chinese Center for Disease Control and Prevention, told reporters from China News Agency on the 29th that "a total of 157 confirmed cases were included in the study. A total of 30 cases of symptomatic infection ", the sample size is small, but the infection rate does have numerical differences.
Zeng Guang believes that from a macro perspective, the domestic newly confirmed cases have basically been “cleared”, indicating that the prevention and control measures are effective. "The emergence of asymptomatic infections has not prevented the domestic epidemic from improving," he said, noting that they should be taken seriously without panic.
The aforementioned experts also made similar judgments. Zhong Nanshan inferred from the facts that "China does not yet have a large number of" asymptomatic infected persons ", and Zhang Wenhong bluntly said that" asymptomatic infected persons are not the mainstream of infected persons. " The World Health Organization has also stated that patients with symptomatic neo-coronary pneumonia are the main source of transmission of the virus.
China's efforts to track "spotters"
In fact, there are similar "latent people" in various infectious diseases, such as Mary Melen, a carrier of typhoid bacteria. She is believed to be related to the typhoid virus infection in the seven families where she works, but she has not developed any symptoms. There were also asymptomatic infections during SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome).
However, the proportion of asymptomatic infections in the new crown pneumonia epidemic is relatively high. A retrospective analysis of 115 children with neonatal coronavirus infection in Wuhan Children's Hospital found that the proportion of asymptomatic infections reached 53%. Authoritative journal Nature published an article stating that "30% -60% of people infected with a coronavirus are asymptomatic or have mild symptoms." Harvard public health scholar Sarah estimates that "40% of the transmission of a coronavirus is asymptomatic."
"Most countries lack a 'heroic effort' like China has made to track asymptomatic carriers," Sarah told the Chinese media. As it says, asymptomatic infections have been included in China's epidemic prevention. The National Health and Health Committee began with the third edition of the prevention and control program released on January 28. Each version of the program defines asymptomatic infections and strengthens management. . The Central Leadership Group Meeting on New Coronary Pneumonia Epidemic Situation held on March 26 also set the focus for the second half of the epidemic prevention: "We must attach great importance to the prevention and treatment of asymptomatic infection."
"The failure to include asymptomatic infections in confirmed cases does not mean that we are less alert to it." Zeng Guang told our reporter that practice shows that the existing prevention and control measures are effective, and the next step to deal with asymptomatic infections is "to believe Overall control effect. "
Take multiple measures to make the "lurker" preventable and controllable
In China, there were four main ways to track the "latent" of the new crown virus: first, active detection during medical observation of close contacts of new crown pneumonia cases; second, active detection carried out in the investigation of cluster epidemics; third, The active detection of the exposed population during the tracking of the infection source, and the fourth is the active detection of the travel history and residence history of some areas with continuous transmission of new cases of neonatal pneumonia. According to reports, asymptomatic infections were identified and observed in isolation after being found, and were not discharged until the nucleic acid test turned negative.
Zhou Qi said that the main direction of prevention and control of asymptomatic infection in the future is "earlier prevention, early warning and detection." In order to maximize the screening of asymptomatic infections imported from abroad, Zhang Wenhong emphasized that "it is necessary to implement the new crown virus nucleic acid test for 100% of immigrants." Another scientist is studying the viral load and duration of asymptomatic infections in order to find the transmission law of the new crown virus.
Interviewed experts give advice to the public. On the one hand, pay attention to self-monitoring, and do not ignore any discomfort such as cough, fatigue, and sore throat; on the other hand, to strengthen self-protection, wear masks and avoid risks in the complex environment where people gather.
Experts also reminded to strengthen the monitoring and control network of medical and health systems. The Political Bureau of the Central Committee of the Communist Party of China held a meeting on the 27th to propose that medical observation, follow-up and rehabilitation during discharge should be done for discharged patients; low-risk areas should "improve normalized prevention and control mechanisms."
Some commenters believe that asymptomatic infection is highly concealed and easily breeds public anxiety, and it is urgent to release information transparently. For some "irresponsible" who are irresponsible and endanger public health, they must "strike hard" according to law. (Finish)