Why are there more and more asymptomatic infected people

Today is the first day of the Qingming holiday, and the anti-epidemic work in some areas is still in full swing. Judging from the case situation released this morning, the situation in Shanghai and Jilin is still grim.

In the face of recent case reports, everyone will have the same questions. Why are there more and more asymptomatic infections? Why is the proportion of asymptomatic infected people vary greatly from place to place?

Image source: Weibo @ People's Daily

Today's hot discussion, let's talk about the topic of asymptomatic infected people infected with the new crown virus. We believe that under today's epidemic, we can consider canceling the data bulletin for asymptomatic infected people.

It is indeed possible that COVID-19 infection will be asymptomatic

Coronavirus, like other respiratory viruses, does not necessarily cause discomfort after infection. This is related to the virus itself and the physical condition of the infected person.

The epidemic has lasted for more than two years, and the new crown virus is also changing, from the original strain to the current Omikejong BA.2 variant, which is mainly less pathogenic. Asymptomatic conditions have increased after infection.

According to current statistics, about 1/3 of infections do not cause symptoms, mainly young infected people.

But not causing symptoms does not equal lower contagiousness. Several studies have shown no quantitative correlation between detected viral loads (which determine the level of infectivity) and symptom severity, and are high even in asymptomatic infected people. In addition, there are also some people who simply have no symptoms at the time of diagnosis of the infection, and do not necessarily have symptoms in the follow-up.

After the new crown virus infection, there can be no symptoms, especially the recent increase in asymptomatic cases, but asymptomatic does not mean that there is no risk of transmission of the virus.

Statistics and disclosure of significance for asymptomatic infected people

Asymptomatic infected people exist, but because they are also contagious, they will not change the epidemic prevention measures for asymptomatic infected people, so what is the significance of statistics?

First of all, it is international practice to make graded judgments on the symptoms of infected people, and the purpose is mainly to deal with them in grades. Different conditions require different measures.

Similar to the asymptomatic and mild symptoms, the common treatment method is to observe, improve symptoms, and expect to recover quickly, without strong medical intervention.

Second, publishing the number of asymptomatic infected people is also a practice of conveying the true power of infection to the public during the pandemic. The public can intuitively understand the risk of the virus through the hospitalization rate, severe illness rate, case fatality rate, and asymptomatic infection rate of infected people.

Our current statistical publications need to be improved

It is clinically significant to count asymptomatic infected people and help distinguish between treatment modalities. It has the meaning of informing the public about the disease. However, because asymptomatic infection is also contagious, it has no significance in affecting the implementation of specific epidemic prevention.

When we did not fully understand the virus in the early stages of the epidemic, we established the classification of asymptomatic infected people, and as an important indicator for the delineation of risk areas for epidemic notification and evaluation, it seems somewhat inappropriate today. The overly subjective evaluation criteria for "asymptomatic infected persons" have led to significant differences in the data across regions, which do not reflect the epidemic situation very well.

In the "Novel Coronavirus Pneumonia Prevention and Control Plan", asymptomatic infected people are defined as follows: those who test positive for the etiology of the new coronavirus and have no relevant clinical manifestations, such as fever, dry cough, fatigue, sore throat, decreased sense of smell (taste), diarrhea and other signs and symptoms that can be self-perceived or clinically recognized, and CT imaging has no imaging characteristics of new crown pneumonia.

In the end, how to judge whether there are relevant clinical manifestations, the doctor's consultation and guidance is very critical, and it can be completely affected by human factors. What kind of attitude doctors use in different regions to diagnose affects whether the infected person is assigned to confirm the diagnosis or asymptomatic infection.

You can feel it, the doctor asks "Do you have any discomfort" and "Do you have a sore throat, think about it really not", is it possible to give a different answer.

Consider never letting go of a diagnosis, or try not to increase the number of confirmed cases so as not to affect the risk classification, which will definitely lead to a completely asymptomatic infection of the number of different people. This is also the reason why the difference between asymptomatic infected people varies greatly, and indirectly leads to the current number of asymptomatic infected people.

Too many subjective factors can affect the judgment of asymptomatic infected people, and if the number of asymptomatic infected people is very important, it will definitely be swayed by human factors and biased.

Adapt to the management of asymptomatic infected people with the times

In order to better reflect the value of the statistics of asymptomatic infected people, do not confuse the public and relax their vigilance. We hope that statistics can be used better in the future.

There is no need to separate confirmed cases and asymptomatic infected people in the immediate epidemic notification, and all infected people are uniformly notified, which intuitively reflects the complete epidemic situation. After the end of the local epidemic, the asymptomatic infected people and severe infections at this stage are summarized and counted, and the public is given more accurate information on the pathogenic capacity of infection.

Instead of considering the real-time statistics of asymptomatic infected people as an important indicator, the pressure on frontline medical staff to make diagnoses is reduced, statistics are turned into a purely clinical science topic, and the numbers are more accurate. It is also conducive to the unified arrangement and management of disease control personnel. It is an important link in concentrating efforts to exchange the minimum cost for victory in the fight against the epidemic.

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Curator: Eric | Executive Producer: Feidi

Cover image source: Dr. Lilac design team