WHO suggests possibility of 'aerosol infection' of new coronavirus, appealing ventilation in addition to hand washing and gargle

The World Health Organization (WHO) has published a report summarizing its research into new coronaviruses, ' Transmission of SARS-CoV-2: implications for infection prevention precautions .' Impact)” was announced on July 9, 2020. In this report, WHO officially mentioned the possibility of 'aerosol infection' that had been pointed out, and cautioned that ventilation should be thoroughly implemented in addition to hand washing and gargle.

Transmission of SARS-CoV-2: implications for infection prevention precautions


WHO says airborne Covid-19 transmission'cannot be ruled out' in outbreaks in some indoor settings-CNN

It is known that the infection route of the new coronavirus is 'splash infection' in which the infection spreads by droplets of 5 micrometers or more secreted when the infected person talks or coughs or sneezes. I will. Therefore, if you are in direct contact with an infected person at close range, or if you make indirect contact through an object contaminated by droplets, the droplets containing the virus will reach the mouth and nose, which may cause infection. ..

Also, as a transmission route of the new coronavirus, there is a possibility of ``aerosol infection'' in which microparticles (aerosol) less than 5 micrometers containing virus drift in the air and inhale by inhaling it Was being done. Aerosol is considered to be generated particularly in medical settings because it is mainly generated by medical measures such as aspiration of sputum.

According to the WHO, most of the reports that the new coronavirus was transmitted via aerosol were in the medical field, but in some cases, chorus practice, restaurants, fitness clubs, etc. Therefore, some papers suggest that aerosol infection may have occurred even if the infected person was in the area for a long time.

Among the research papers so far, WHO acknowledges that there was a case where RNA of new coronavirus was detected in the air. However, it should be noted that the fact that 'RNA was detected' does not mean immediately that 'the aerosol containing RNA is infectious', and that no case was detected in the same investigation. WHO said no nosocomial transmission of the new coronavirus was not observed if health care workers were wearing medical masks and had adequate contact and splash precautions.

WHO said 'whether aerosols containing infectious new coronavirus can be detected in the air in situations other than medical settings where aerosols are generated' and 'whether aerosols can be an infection route' It is unclear at the time of writing, and further research is needed.

WHO shows the following six points in the report.

・Understanding when, under what circumstances and how the new coronavirus spreads is important for public health and infection control measures to break the chain of infection.
-The current evidence is that new coronaviruses are transmitted through direct or indirect contact with infected persons via droplets of saliva and respiratory secretions.
• Aerosol-borne airborne infections may occur in some medical settings where aerosols are produced. In addition, in a crowded indoor space, a combination of droplet infection and aerosol infection may spread.
・There is a possibility of being infected by touching the eyes, nose, or mouth with the hand that touches the contaminated object due to the splash of the infected person.
・The new coronavirus can be transmitted not only from infected individuals who exhibit symptoms but also from asymptomatic infected persons. However, it is very difficult to track how far the infection spreads from asymptomatic individuals and further investigation is needed.
-It has not been clarified whether aerosol infection occurs in a space where no aerosol is generated, that is, how much virus is required to cause airborne infection, and high-quality research is urgently needed.

In addition, as a countermeasure against infection, WHO has presented the following.

• Quickly identify suspicious cases and quarantine all infected persons at appropriate facilities.
-Identify intimate connections with infected persons and isolate them for treatment in the event of infection or development.
-Wear a mask that covers your nose and mouth securely in public places where you cannot take preventive measures such as maintaining a physical distance.
-Healthcare workers who will house persons infected with or suspected of being infected with the new coronavirus will take precautionary measures to prevent contact and droplet infections, and to take airborne infections if aerosols are generated.
-Health care workers and caregivers wear medical masks on a daily basis.
・Wash your hands well and keep a good distance from others. Do not go to a crowded place, a place where they are in close contact with each other, or a closed space with poor ventilation. Wear a cloth mask in an overcrowded space. All enclosed spaces should be properly cleaned and disinfected.

in Note, Posted by log1i_yk