Notice on Scientific and Accurate Development of Nucleic Acid Detection Services
According to the requirements of "novel coronavirus Prevention and Control Plan" and "Notice on Further Optimizing the Prevention and Control Measures of COVID-19 Epidemic" of the State Council Joint Prevention and Control Mechanism Comprehensive Group, the relevant matters concerning the scientific and accurate development of nucleic acid testing services in our city are hereby notified as follows:
First, according to the principle of "voluntary, take away and not restrict the flow", the inter-provincial migrant workers with "two stations, one field and one dock" will continue to carry out the "landing inspection" of nucleic acid.
Second, the red code personnel take the initiative to report to the local community and wait for the on-site nucleic acid test at the residence as required. Yellow code personnel go to designated medical institutions for nucleic acid testing, during which they are required to wear masks and do not take buses.
Three, risk positions, key personnel to implement the "inspection" as required.
Four, citizens who need nucleic acid testing can sample at their own expense at social convenience points.
Five, in the whole process of nucleic acid sampling, you must wear a mask, keep a distance of 1 meter with others, and don't talk or gather.
Six, no COVID-19-related symptoms, non-dangerous posts, non-key personnel and citizens of no demand, advocate not to carry out nucleic acid testing.
This notice shall come into force as of February 4, 65438, and shall be dynamically adjusted according to the epidemic situation and prevention and control requirements. Thank the general public for their understanding, support and cooperation in the prevention and control of epidemic situation in our city.
Extended reading
It is difficult to find the box after opening it. Do I need to prepare an antigen kit?
On February 2, 65438, Chengdu, Tianjin, Beijing and other places announced the cancellation of the inspection of subway nucleic acid certificates. On the same day, Guangzhou also announced that ordinary outpatient and emergency medical staff of various medical institutions at all levels will pass by health code green code.
65438+February 1, after the temporary control area for epidemic prevention and control was lifted in several districts, the Guangzhou Municipal Health and Health Commission mentioned that different nucleic acid detection strategies should be adopted for different groups of people to encourage families to bring their own antigen kits.
Subsequently, some communities began to buy antigen kits, and antigen detection reagents in many pharmacies in Guangzhou were out of stock. On February 2nd, 65438, Li Ding, deputy director and spokesperson of Guangzhou Municipal Market Supervision Administration, introduced that Guangzhou was coordinating COVID-19 antigen kit manufacturers to increase their production capacity reasonably. At present, the maximum production capacity of Guangzhou COVID-19 antigen kit is about 1050000 person/day.
On February 2, 65438, the Beijing Municipal Health and Health Commission also issued a document mentioning that citizens are the first responsible person for their own health, "do a good job in personal protection and health monitoring, and make good use of nucleic acid detection and antigen self-test". 65438+February 1, Beijing Health and Health Commission announced measures to optimize daily diagnosis and treatment, in which it was mentioned that for patients with negative nucleic acid results within 48 hours, antigen should be tested again during triage, and triage should be conducted according to the test results.
What role will antigen testing play in the future? Who wants an antigen test?
Ordinary people don't need to do antigens every day.
In March of this year, the "Application Scheme for Antigen Testing in COVID-19" was issued, and antigen testing was opened to three types of people as an auxiliary means of nucleic acid testing. These include patients who go to primary medical and health institutions and have symptoms such as respiratory tract and fever within 5 days, isolation personnel and residents who need antigen self-examination for early detection and isolation. However, the "Program" mainly aims at professional medical institutions and testing personnel to carry out antigen testing on patients, emphasizing the first choice of nucleic acid testing.
As early as 2020, some countries, such as Europe and America, have used antigen detection as an auxiliary means of nucleic acid detection to screen COVID-19 infection.
The State Key Laboratory of Virology of Wuhan University has an image metaphor, which imagines novel coronavirus as an orange, and the virus nucleic acid is orange petals wrapped in orange peel and endothelium. Antigen detection is to judge whether the virus exists by detecting orange peel or endothelium. In nucleic acid detection, it is necessary to peel off the orange peel and endothelium. After the orange peel flap is exposed, it will continue to expand, that is, the gene fragment carrying the virus will continue to expand, thus being detected by the instrument, and finally judging whether there is viral nucleic acid.
The antigen detection operation is simple, and the result can be quickly detected in 10~20 minutes, and the price is cheap. However, compared with nucleic acid detection, the accuracy is low.
In March this year, Li, deputy director of the Clinical Laboratory Center of the National Health and Family Planning Commission, introduced that the sensitivity of antigen detection reagents approved by the state was between 75% and 98%, and the specificity was between 95% and 99%. Li mentioned that antigen testing cannot replace nucleic acid testing. When the antigen test is positive, you must do nucleic acid test to confirm the diagnosis.
The US Centers for Disease Control and Prevention also mentioned that antigen detection is not as accurate as nucleic acid detection, and it may not be possible to detect the virus in people with early infection or asymptomatic symptoms. It is recommended to test continuously for 2~3 days. "The self-test of family antigens is not perfect, but it provides a quick and convenient option to detect whether they are infected with COVID-19."
Jin Dongyan, a professor and virologist at the School of Biomedicine of the University of Hong Kong, told China Newsweek that about 60%~75% of all confirmed cases in Hong Kong were detected by antigen. A large-scale study in the United States shows that the specificity and sensitivity of antigen are very close to that of nucleic acid after three consecutive tests, and about 98% of infected people can be found. "It can be tested every day or every other day, usually at least three times every three to five days."
A public health expert who did not want to be named stressed that in the early stage of the COVID-19 epidemic, when the number of infected people was small, nucleic acid testing could quickly screen out infected people. However, when there is widespread social transmission, centralized nucleic acid detection is prone to cross-infection, and the risks and benefits are not equal. In contrast, the threshold of antigen testing is low, and people can follow the instructions at home, which can effectively avoid this risk.
Who needs antigen testing? Under what circumstances is antigen testing used?
During the fifth wave of epidemic in Hong Kong, the SAR Government distributed 10 to 20 boxes of antigen testing reagents to every family, and asked them to test themselves for three consecutive days. "At that time, a considerable number of recessive infected people were found out at once." Jin Dongyan said. He suggested that in the early stage of a large-scale outbreak, as many antigens as possible should be detected in the first round. On the one hand, the antigen detection result is fast, which can improve the efficiency of primary screening, find potential infected people and then find the whole infection chain; On the other hand, the cost of antigen detection is lower than that of nucleic acid, which can effectively reduce the economic burden of grassroots.
Many experts believe that it is unnecessary for most ordinary people to do antigen testing every day. Antigen testing is mainly used to screen high-risk groups. Jin Dongyan introduced that in Hong Kong, there are two groups of people who need continuous antigen testing, high-risk groups and specific groups. High-risk groups include the elderly and employees in nursing homes, medical staff, and frontline workers, such as employees in isolated hotels and airports. Specific populations are dynamically adjusted according to the high-risk points involved in positive patients, such as people who stay in places related to positive patients for more than two hours, or people who are delineated near places where the amount of virus is extremely high through sewage sample detection.
Jin Dongyan believes that antigens can also be considered as access cards for specific places such as schools, hospitals and shopping malls in the future to ensure the necessary operation of society. For example, students in Hong Kong should do antigen testing at home before going to school every day, and medical staff should also do antigen testing before going out to avoid hospital feeling. In addition, infected people will receive two antigen tests on the 6th and 7th day of community or family isolation respectively. If the test results are negative for two consecutive days, the isolation can be lifted.
In accordance with the provisions of Article 20 on optimizing prevention and control, in epidemic-free areas, the risk posts and key personnel shall be tested for nucleic acid in strict accordance with the scope determined in the ninth edition of the prevention and control plan, and the scope of nucleic acid testing shall not be expanded. According to the ninth edition of the prevention and control plan, after the occurrence of 1 local epidemic cases and above within the jurisdiction, at least 20% of the nucleic acid samples can be taken from key institutions such as schools and nursing homes every day according to the detection results and the risk of epidemic spread, in addition to completing the whole process of 1 nucleic acid detection.
The above-mentioned public health experts told China Newsweek that, from the perspective of finding the transmission chain, it is "definitely not enough" to carry out nucleic acid testing in such key places according to the sampling ratio of 20%, and to supplement antigen testing, "it is best to do it every day, or at least 3-5 times a week".
Jin Dongyan explained that antigen and nucleic acid detection are complementary. If the antigen test is positive, nucleic acid is used to determine the virus amount and risk of infected people, which is an important basis for taking corresponding isolation measures. Good steel is used on the blade. In addition to continuous antigen testing for high-risk personnel, Hong Kong also stipulates that nucleic acid testing must be conducted once a week, which is equivalent to "double insurance".
Lu Ji Meng, a German Chinese virologist and professor at the Institute of Virology, Essen University School of Medicine, told China Newsweek that the biggest advantage of expanding antigen testing is that "some super communicators" can be directly screened out and isolated in time.
On February 2, 65438, Guangzhou announced that ordinary emergency medical staff in hospitals at all levels were allowed to pass by green health code, and newly admitted inpatients and their accompanying staff were allowed to enter by 24-hour negative nucleic acid certificate. Jin Dongyan analyzed that, in contrast, the risk of hospitalization is higher, so the requirements for admission are also high. However, he suggested that more antigens can be detected, supplemented by nucleic acids, to reduce the risk of hospital infection.
"This is not just a medical problem, but a social management problem."
After the promulgation of the "Program", antigen testing has been carried out in Shanghai, Hebei and other places since April this year as a supplementary means of nucleic acid testing.
Many interviewed experts mentioned that antigen testing is the general trend and also helps to reduce the cost of epidemic prevention. However, in the opinion of the aforementioned public health experts, if antigen testing is to be carried out, the requirements for system and management are higher than those for nucleic acid testing. He said: "In the past, everyone only needed to cooperate with nucleic acid testing, but after antigen testing, who should pay for the testing, whether it can cover everyone, and how individuals can accurately report the results need to be considered."
In his view, this is not just a medical problem, but a subject of social management. At present, Guangzhou only encourages families to bring their own antigen kits, and there is no specific requirement on how to land.
Network picture
After Guangzhou encouraged families to bring their own antigen kits, some netizens said on social platforms that it was free nucleic acid testing before, and they had to pay their own expenses if they didn't adapt to antigen self-testing. On February 2nd, 65438, Guangzhou Tianhe, Haizhu District and other districts began to introduce self-funded convenient nucleic acid sampling points, and the mixed management fee was 2.8 yuan/person. Nucleic acid detection services in major hospitals have also begun to resume at their own expense, with single tube 13.5 yuan. In contrast, the price of a single antigen detection reagent is mostly within 10 yuan.
Jin Dongyan said that in Hong Kong, the SAR government will distribute rapid antigen detection kits to the above two high-risk groups free of charge. If there are many infected people in a residential area or building recently, a joint team composed of HKU and the SAR government will also test the nearby sewage. If the virus in the sewage sample is found to be high, antigen detection reagents will be distributed to nearby residents, cleaners and property management personnel free of charge. Others need to be purchased at their own expense, and employers in some institutions will also provide antigen reagents to employees free of charge.
Secondly, whether the individual will accurately report the antigen test results is also a problem that needs to be considered. "Building a declaration system, ensuring the accuracy of the declaration system, auditing antigen reagents and driving inferior manufacturers out of the market require further exploration by the state regulatory authorities." Jin Dongyan told China Newsweek.
Some cities have set up declaration platforms. In April, in response to the "Program", the Guangdong Provincial Health and Health Commission launched the "Guangdong Antigen" applet to support residents to collect antigen detection information and report the results, and connect with local Guangdong Jiantong, Guangdong Nucleic Acid applet and electronic health code. In May, Hebei Province launched the "antigen report" applet. Beijing Health Big Data and Policy Research Center has also launched "Beijing Antigen", and citizens can upload antigen test results through small programs.
Jin Dongyan introduced that in Hong Kong, people in the above-mentioned key places found positive after daily antigen self-examination, which can be automatically reported through the "Rapid Antigen Test Positive Result Reporting System" launched by the Health Protection Center of the Hong Kong Department of Health in March. In order to encourage people to take the initiative to use the system, if residents upload antigen results on the system to make an appointment for nucleic acids, the government will distribute a free gift package, including epidemic prevention guidelines, antipyretics, electronic thermometers, 20 boxes of antigen detection reagents and 20 KN95 masks. Residents who do not use the system to report will have to pay hundreds of yuan for testing at their own expense.
He added that in order to further verify the accuracy of antigen testing, Hong Kong will regularly check 65,438+00% ~ 30% of reported antigen-positive patients.
However, the above-mentioned public health scientists stressed that promoting antigen testing and making individuals the first responsible person of health require high social management. In addition, he suggested that if antigen testing is to be carried out, how to implement and supervise it should be adjusted and revised in the prevention and control plan of novel coronavirus, rather than explained by local governments, which will help local governments to implement it in accordance with unified regulations.
Author: Yang Zhijie Huo Siyi