A new publication studies what happened in a restaurant and how air conditioning, an ordinary element in any place that serves food, could have helped infect at least nine people with COVID-19. This is the first work to suggest that air conditioning could play a role in COVID-19 transmission.
The analyzed date took place on January 24, 2020 in the restaurant on the third floor of a building in the Chinese city of Guangzhou. There, at lunchtime, were 83 diners, including a family of four (known as Family A) who had returned from Wuhan, the city where the viral outbreak is believed to have originated, the day before.
That same afternoon, one of the people who had returned from Wuhan (person A1) began to feel ill with a sudden onset of fever and cough, and went to the hospital. By February 5, a total of 9 other people were eating at the restaurant that day, including 4 members of family A, as well as five members of two other families who sat at neighboring tables (families B and C), had become ill with COVID-19.
The researchers suggest that the isolated outbreak could be connected to the air flow of an air conditioning unit, which moved respiratory drops around the restaurant without ventilation.
The study tracked customers who had attended the restaurant during lunch hours, pinpointing where they sat and the path of air transmission from the restaurant’s air conditioning units. Apparently, those who were infected with COVID-19 sat in the same airflow path as infected patient A1. Those who did not sit on this path of air flow were not infected.
In this way, the authors conclude that in this outbreak, the transmission of droplets was caused by ventilation with air conditioning. The key factor for infection was the direction of air flow.
The study was carried out by the Guangzhou Center for Disease Control and Prevention (CDC), and is currently being peer-reviewed for official publication in July. However, the Chinese CDC has published it previously due to the timely nature and importance of the findings.
Link to the paper: https://doi.org/10.3201/eid2607.200764
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.