As the temperature fluctuates recently, organising hotpot dinners seem to be a good choice. Yet it became a bad idea after a family hotpot gathering has caused more than ten contractions of the coronavirus. Furthermore, a mainland Chinese authority stated that the COVID-19 can be transmitted through “aerosol,” which was rumored to be linked to steamy scenarios such as boiling soup or going to a sauna.  As a result, no one dares to have hotpot or go to a sauna at the moment.

So what exactly is aerosol and how does the COVID-19 spread through it? Is there a direct correlation between hotpot and sauna with getting infected? 

Virus is not transmitted by air

First and foremost, aerosol transmission is not airborne transmission! Moreover, aerosol transmission seldom occurs within the community. There is, therefore, no reason to panic just because we are unfamiliar with this term, and surgical masks shall provide sufficient protection for your daily life.

Aerosol transmission phenomenon was first identified during the time of SARS, at the Ward 8A of the Prince of Wales Hospital. In simple term, aerosol is the conversion of droplets into minute particles that can stay and spread in the air. The formation of aerosol is usually linked to medical procedures, such as sputum suctioning, intubation and bronchoscopy. Activities such as using a steam iron will not lead to aerosol formation even though there are steam creation.

Will hotpot generate aerosol?

Hotpot and sauna will not generate aerosol. When we do hotpot however, people tend to sit relatively close to each other, making transmission of disease through droplets easier. So it is wise to avoid such social activities during the epidemic.

Is aerosol generated in the toilet?

The outbreak at Amoy Garden during SARS regard as a very exceptionally case on aerosol transmission. The dried U-trap is failed to seal the virus and lead to aerosol transmission, further extracted by the exhaust fan. To reduce the chance of getting an infection in the toilet, there are a few things that we should do:

1. Cover the lid when you flush the toilet;
2. Pour 500cc water into the drain every week; and
3. If you detect a foul smell in the toilet, have it checked by a professional.

All in all, one should be quite safe during an epidemic if he or she is vigilant with personal hygiene, avoids crowded places and paranoia.

Dr Alexander Chiu, Medical Director, Health and Employee Benefits, AXA Hong Kong and Macau