Chinanews.com, Shanghai, December 26th (Reporter Zheng Yingying) After the "yang", how long will it take us to recover and go out with peace of mind?
Do you need to carry out "whole family disinfection"?
On the 25th, Zhong Ming, director of the Department of Critical Care Medicine, Zhongshan Hospital Affiliated to Fudan University, spoke to the public about epidemic prevention and answered questions at the Shanghai Science Popularization Forum.
On December 25, Zhong Ming, director of the Department of Critical Care Medicine, Zhongshan Hospital Affiliated to Fudan University, came to the Shanghai Science Popularization Forum to carry out epidemic prevention science.
Photo courtesy of Shanghai Science and Technology Museum
How long will it be non-infectious after being "positive"?
Zhong Ming said that the nucleic acid test (after infection) will be positive very early. Generally, after the nucleic acid is positive, there is such an incubation period, which is the so-called asymptomatic period. The asymptomatic period may be one day or three days, and each virus strain is different. .
From the positive nucleic acid to the onset of symptoms, which is the so-called asymptomatic period, there are no symptoms for 1 to 3 days, but at this time there may be mild infectivity.
At this time, the longer the asymptomatic period, the stronger the transmission ability.
Then there are symptoms, that is, the infected person feels a sore throat and coughs. This is often the time when the antigen can be detected. It can be said that the antigen-positive is almost the same as the time when the symptoms appear, and it may be a little later. So basically When the antigen is positive, the detoxification also reaches a peak, and it is contagious at this time, which is the peak time.
The antigen is very similar to the peak (time) of symptoms. The antigen-positive time is very short, and it goes down quickly. That is to say, when the symptoms of the infected person are gradually relieved, the antigen (reaction) also goes down.
What do we usually say is contagious?
That is, the infected person can excrete live virus, which is contagious.
Studies have shown that after 7 days of general infection (Omicron) (average 7 days to 9 days), live virus will no longer be excreted, and there will be no infectivity. This time is relatively consistent with the time of our antigens, which is consistent with symptoms The timing is also relatively consistent.
That is to say, about a week after infection (symptoms disappear in about a week), basically there is no infectivity, or if the antigen turns negative, there is no infectivity.
But in about a week, the level of nucleic acid is still very high, so at this time, the nucleic acid test of the infected person is still positive, but the positive nucleic acid (at this time) does not mean that they are infectious.
How to disinfect after the whole family is "yang"?
Zhong Ming said that if the whole family is infected, they will not be re-infected by the excreted virus. The infected people already have resistance and antibodies.
After the infected person recovers, in fact, no new virus will be excreted. The virus existing in the environment will die after more than 3 days, so there is no problem.
So when the infected person recovers, it has been 7 to 10 days. He thinks that everyone can clean normally, and there is no need to face the enemy every day and fill the room with disinfectant to disinfect.
On December 25, Zhong Ming, director of the Department of Critical Care Medicine, Zhongshan Hospital Affiliated to Fudan University, came to the Shanghai Science Popularization Forum to carry out epidemic prevention science.
Photo courtesy of Shanghai Science and Technology Museum
Is the probability of secondary infection high?
In response to this problem, Zhong Ming said that some people will be infected multiple times. One is that they have encountered different strains, and the other is that the antibody level has dropped after the previous infection. They will still be infected, but there is a time period. According to reports The shortest "world record" is 20 days (secondary infection occurs), but it is rare. Most people are under the same strain or similar strains, and it should be safe within 3 months.
For example, if a person was infected with Delta before, and encounters the spread of Omicron at this time, he (she) still has a probability of being infected with Omicron because of immune escape, but the probability will be lower.
But if the infected person is Omicron BA.2 this time, and then you have to face Omicron BA.5 or BF.7, there is still (probability of infection), but the probability is lower than that of Delta , when the strain is closer, the probability of infection will be lower.
For most citizens, Zhong Ming said that after recovering from this infection, during this epidemic period, there will be no re-infection in a short period of time. The probability is very low, because generally they face the same or very similar strains.
Regarding "Wang Chongyang" (repeated infection), will the infection continue?
He said, in fact, no, the same virus strain, conservatively speaking, is safe within 3 months (after infection), unless there is a small probability event, for example, someone in the family recovered, went to another place, and was infected with a completely different virus. The probability of bringing the strain back home is very small.
(use up)