The epidemic is recurring and all people in many places across the country are undergoing nucleic acid tests. Is it safe to queue up for nucleic acid tests? How to reduce the risk

The Delta strain is coming in with great force. So far, it has spread to 15 provinces and 33 cities. Many places have restarted nucleic acid testing for all people. Some friends may ask: "Will queuing up for nucleic acid testing increase the risk of infection? And further spread the virus?" We need to use a dialectical approach to solve this problem.

Why do we conduct nucleic acid testing for all? First of all, we need to understand why we conduct nucleic acid testing for all. The spread of any infectious disease depends on three factors: the source of infection, the route of transmission, and the susceptible population. The spread of the new coronavirus is also inseparable from these three factors. In order to prevent the spread of the epidemic, what we need to do is to control the source of infection, cut off the route of transmission, and protect the susceptible population.

Controlling the source of infection is particularly important. Only by timely discovering and controlling the infected in the crowd can we more effectively protect those who are not infected with the virus. For ordinary epidemics, we can isolate the confirmed cases and their close contacts through epidemiological investigation, but the epidemiological investigation of the new coronavirus is too difficult. The traceability of respiratory diseases is difficult. With the emergence of the Delta strain, many infected people have no obvious symptoms. There are a large number of asymptomatic infections in the crowd, which greatly increases the difficulty of epidemiological investigation. Even until now, we have not found "Patient No. 1" and "Patient No. 0" in Hebei or Guangzhou.

Since tracing the source is difficult, the only way to find infected people is to conduct full-population testing. Although it is time-consuming and labor-intensive, it is currently the most effective way to find infected people. The efficient full-population nucleic acid testing played a crucial role in the previous epidemics in Hebei and Guangzhou.

Will centralized nucleic acid testing increase the risk of infection? In theory, centralized nucleic acid testing will increase the risk of infection, but everything must be weighed against the pros and cons.

While queuing for nucleic acid testing, once there are people infected with the new coronavirus in the crowd, they become close contacts for ordinary people who are tested in the same time period, which theoretically increases the risk of infection. Once the test results are confirmed, only people in the same time period need to be quarantined in a centralized manner.

If centralized testing is not conducted and the infected person is not discovered, he is equivalent to a mobile spreader. Thousands of people walking on the streets every day will unknowingly become close contacts. What's worse is that even if he develops symptoms and goes to the hospital and is identified as an infected person, those close contacts on the street will be difficult to track down. In other words, the difficulty of epidemiological investigation is greatly increased.

The method proposed by some people of having medical personnel conduct door-to-door testing is even more impractical. Take Nanjing as an example. With a floating population of about 10 million, how can we conduct nucleic acid testing door-to-door? Even if we only check it once, it will probably take several weeks or even months. When we adopted the centralized testing method, it took only 3 days to complete the first round of nucleic acid testing for all people, which is crucial for the control of the epidemic.

How to reduce the risk of infection during centralized testing? 1. Wear a mask

For respiratory diseases, wearing a mask can protect us from infection to the greatest extent. Over the past year or so, masks have played a "key" role in preventing the spread of the new coronavirus, so be sure to wear a mask strictly when going for nucleic acid testing.

2. Keep a certain distance between front and back

An article published in the internationally renowned medical journal The Lancet shows that keeping a distance of at least one meter between people can help reduce the risk of contracting the new coronavirus, which is why we previously emphasized that people should sit apart from each other when participating in group activities. Keeping a distance of at least one meter before and after nucleic acid collection will reduce the risk of infection.

3. Wash your hands first when you get home

In addition to respiratory transmission, contact transmission can also lead to infection with the new coronavirus. The virus infects the human body through hands touching mucous membranes such as the mouth and eyes. To prevent infection, do not touch your mouth or eyes after returning home, and wash your hands first to reduce the risk of infection.

Universal nucleic acid testing has played an important role in the epidemics in Guangzhou, Hebei and Yunnan. I believe that with everyone's efforts, the epidemic will be effectively controlled soon.