Can air-con spread Covid-19?
A research letter published by Guangzhou Centres for Disease Control in China looked at 10 coronavirus cases of 3 families who ate in adjacent tables at the same time. The study proposes that droplet transmission by the restaurant’s air conditioning system was increased. The initial patient arrived from Wuhan and dined at the restaurant with 3 family members.
Two other families sat nearby. Later that day, the initial patient felt ill and checked into the hospital where he tested positive for Covid 19. Shortly thereafter, the two other families tested positive. The windowless restaurant had an air-con vent on one side of the room, and an outflow vent on the other. The families dined in the restaurant for around an hour in close proximity.
The study discovered that virus transmission in this outbreak could not be explained by droplet transmission alone stating, “Larger respiratory droplets remain in the air for only a short time and travel only short distances, generally. The distances between the initial patient and persons at other tables were all less than 1 metre. Therefore, strong airflow from the air conditioner could have propagated droplets from table to table “.
Figure . Sketch showing arrangement of restaurant tables and air conditioning airflow at site of outbreak of 2019 novel coronavirus disease, Guangzhou, China, 2020. Red circles indicate seating of future case-patients; yellow-filled red circle indicates index case-patient.
Abstracts from the research suggest “The airflow direction was consistent with droplet transmission. To prevent the spread of the virus in restaurants, we recommend increasing the distance between tables and improving ventilation of fresh air.”
SOURCES: The Nation | CDC
