The novel coronavirus pneumonia epidemic situation was released on the afternoon of April 1st, and the website of the National Health Protection Committee and the Hubei Health Protection Committee announced the latest situation as of March 31st. The novel coronavirus pneumonia is the first official notification of asymptomatic infections in the daily epidemic notification since the outbreak of the new crown pneumonia. On March 31, 130 new asymptomatic infections were reported in 31 provinces (autonomous regions, municipalities directly under the central government) and Xinjiang production and Construction Corps. On that day, 2 cases were confirmed and 302 cases were released from isolation. 1367 cases of asymptomatic infection were observed in medicine, 174 cases less than the previous day. On the same day, 47 cases of asymptomatic infection were newly increased in Hubei Province, 1 case was confirmed on the same day (imported from abroad), 289 cases were removed from isolation, and 982 cases of asymptomatic infection were still under medical observation. The number of asymptomatic patients in medical observation was 71.8% in Hubei Province. How is asymptomatic infection detected? Is it contagious? Is there more asymptomatic infection in China? What are the requirements for prevention and control? Reporters from China Economic Weekly sorted out the issues most concerned by the people one by one.
How is asymptomatic infection detected?
Asymptomatic infection of new coronavirus refers to those who have no relevant clinical symptoms, such as fever, cough, pharyngeal pain and other symptoms and signs that can be self perceived or clinically recognized, but whose respiratory tract and other specimens are positive in etiology test of new coronavirus.
At present, asymptomatic infection is mainly found through the following ways:
First, the novel coronavirus pneumonia cases were closely contacted with the active medical examination during medical observation.
Based on the novel coronavirus pneumonia incubation period of about 14 days, there were cases of human transmission, and medical observation was conducted by close contacts in various organizations. As of 24:00 on March 31, 707913 close contacts have been traced in China, and 20314 close contacts are still under medical observation.
The second is the active detection in the cluster epidemic investigation.
For example, novel coronavirus pneumonia epidemic occurred in Jintan District of Changzhou City, Jiangsu province in February. According to the investigation of the expert group, asymptomatic infection is the main factor in the epidemic.
Three, novel coronavirus pneumonia cases are tracked in the process of tracing the infection source.
In the novel coronavirus pneumonia case, the asymptomatic infection may be detected when the exposure population is actively detected.
Novel coronavirus pneumonia cases in four areas continue to spread in the area of travel history and residential history personnel active detection.
For example, since zero o’clock on March 25, all the entry personnel from Beijing port, regardless of destination, have been isolated and observed on the spot, and all have been tested for nucleic acid. Shanghai, Guangzhou, Chongqing and other cities have taken similar measures. According to incomplete statistics, asymptomatic infections have appeared in recent years. From the official information of asymptomatic infected people, we can further understand the channels through which asymptomatic infected people are found.
In the early morning of March 12, Hangzhou CDC reported an asymptomatic infected man, 49 years old, engaged in international exchange services. When the personnel went to the hospital for routine physical examination, the doctor learned that he had contact with personnel from overseas high-risk countries in the past 14 days, so he collected samples for testing, and the test results were positive.
On March 16, a asymptomatic imported patient was found in Guiyang. This person, male, 20-year-old student, is an overseas returnee to Guiyang. He transferred from London, UK to Chengdu via Hong Kong and then took the high-speed rail to Guiyang.
On March 17, the health and Health Commission of Mianyang City, Sichuan Province announced that Luo, who returned from Spain on March 13, was asymptomatic and was currently receiving medical isolation observation in a designated hospital.
In March 27th, novel coronavirus pneumonia positive patients were diagnosed as asymptomatic infection by 1 patients with thyroid diseases who were admitted to a hospital in Jingmen, Hubei province (South District) and tested by nucleic acid test on 28 March.
In March 29th, 1 novel coronavirus pneumonia cases were imported into Qingdao. Patient Li, female, 24 years old, Chinese, from Qingdao, studying in the UK. Li, who arrived at Qingdao Liuting Airport from London on March 21, was transferred to the centralized isolation point of the West Coast new area for medical observation by “point-to-point”. On March 22, nucleic acid test was positive, and on March 23, nucleic acid retest was positive, but there was no clinical symptom. On March 29, Li had fever and lung changes. Combined with the clinical manifestations and laboratory examination results, the expert group confirmed the common case and transferred it to the designated hospital for isolation treatment.
In March 31st, 1 novel coronavirus pneumonia confirmed cases in Hubei were imported from Wuhan (from asymptomatic to confirmed cases). Zhou XX, male, 16 years old, registered in Caidian District, Wuhan City, studying in the UK. Starting from the UK on March 21, transfer to Beijing Capital Airport via Dubai airport on March 22. After the temperature test and relevant procedures, the Hubei reception party arranged a single room accommodation. On March 23, it arranged to take the high-speed rail to Wuhan station on the night of Beijing west station, and arranged to separate observation at the isolation point. On March 28, the nucleic acid test results of the patients were positive, and the patients with asymptomatic infection were reported.
On March 31, a new case of asymptomatic infection was imported into Yunnan Province (Chinese, Saudi Arabia). The patient, a 16-year-old student, took a flight from Saudi Arabia on March 12 and arrived in Kunming on March 14. The nucleic acid samples from the airport were negative. Send to the centralized medical observation point for centralized observation. On the 19th, the nucleic acid samples were negative, and the body temperature was normal during isolation. On the 31st, re sampling nucleic acid test was positive