Currently, the epidemic in Wuhan presents a severe situation of multi-region and multi-point, intertwined distribution and aggregation, and continuous rise. The risks of hidden transmission, cross-infection and community spread continue to exist. On the 27th, public health experts reminded the public that be vigilant against the aerosol transmission of Omicron virus in a relatively closed environment, and home prevention is particularly important .
Aerosol transmission “prefers” humid confined spaces
Since this year, reports from multiple places have shown that Aggregate infection due to aerosol transmission occurs in confined spaces.
In March, a 33-story building broke out in a certain place In a clustered epidemic, a total of 62.9% of the confirmed cases lived in vertical buildings with 18 different floors (rooms). According to the epidemiological investigation, these cases were not close contacts, and it was speculated that vertical transmission of aerosols across floors occurred.
At the beginning of this month, another place held an epidemic prevention and control At the press conference, disease control experts also mentioned aerosol transmission: Many local newly infected people are concentrated in the urban village area, with dense population and narrow space. When there are infected people, the discharged virus is very easy to spread in the area. Forms aerosols which are difficult to dissipate within a short time.
Recently, according to the analysis results of traffic survey data in Wuhan , There were 12 new cases of infection in the same building in a certain community. Gene sequencing and flow investigation showed that the infected people all lived in the same type of room above a certain positive case in the building, belonging to the same transmission chain, according to the time of onset Look, the residents on the ground floor turned positive first, and the residents upstairs were infected later. Therefore, it is speculated that the infection may be caused by aerosol transmission through the ventilation ducts in the bathroom and the kitchen flue.
“ Aerosol transmission is easier to spread quickly in humid, closed, and crowded spaces and can quickly cause a large number of people to be infected.” said the expert.
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Why can aerosol transmission be transmitted upstairs and downstairs?
According to experts, the essence of aerosol is that it can suspend Particles in the air. Aerosols can be suspended longer and farther than normal airborne transmission. When the new coronavirus is attached to dust, droplets, or droplet nuclei that have lost moisture, it can be airborne in the form of aerosols.
In an unventilated environment, aerosols containing viruses can stay in the air for a longer period of time. For example, after an infected person takes an elevator, aerosols containing the virus may appear in the elevator, and the air circulation in the elevator is poor. will increase.
But it needs to be emphasized that aerosol transmission also has a prerequisite , the public need not panic. The distance that droplets can travel is very short, and they will not float in the air for a long time,Aerosols that are difficult to dissipate in a short time may form only when the air circulation is poor. In response to aerosol transmission, the public needs to be vigilant, but there is no need to panic.
Family prevents aerosol transmission
Indoor aerosol transmission risk is greater than outdoor, family The proportion of indoor transmission of clustered epidemics is greater, so it is necessary to focus on home prevention.
First of all, open the windows frequently for ventilation. Open the windows regularly more than 3 times a day, try to open the opposite windows in the living room to form convection, control the duration to about 30 minutes, and completely replace the indoor air as much as possible. Effectively eliminate the spread of aerosols in confined spaces.
Secondly, do a good job of sewer protection.The water in the sewer backwater bend can seal the pipeline and effectively prevent gas Sols enter. Citizens can check the water seal status of toilets and shower drainage floor drains in their homes, and replenish water in time to prevent aerosols from spreading through the pipes. If the floor drains do not have water seal conditions, they can also be covered after use, or sealed with tape If these conditions are not met, you can also use a fresh-keeping bag to fill it with water and tie it tightly, and put it on the floor drain as a sealing cover.
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Thirdly, protective details are also required when using the bathroom.After using the toilet, cover the toilet lid before flushing to avoid aerosol splashing outside the toilet. Windows should be strengthened for ventilation in the bathroom to keep the air flowing. If the bathroom has poor ventilation , it is recommended to turn on the exhaust equipment for ventilation.
In addition, the frequency of indoor cleaning can also be increased in the near future,Reduce indoor dust, Helps clean the air.
“Whenever you Strictly follow the prevention and control requirements to do a good job of personal protection, including in the elevator going up and down the stairs. “Experts also emphasized that citizens must wear masks correctly when going out, wash their hands frequently, and keep a safe distance of more than one meter from others. When sneezing or coughing, cover your mouth and nose with a tissue or elbow. Current research shows that under the action of gravity , most of the droplets fall to the ground within a distance of about 0.8 meters to 1 meter. Therefore, wearing a mask and keeping a distance can achieve a double prevention effect.
The epidemic is not over yet, the epidemic prevention cannot be slack
Source:Changjiang Daily