Sitting side-by-side in a cafeteria, particularly when the diners are not conversing with each other, reduces the risk of transmission of SARS-CoV-2 during meal times, says a recent study from South Korea published in the Journal of Korean Medical Sciences.

The study investigated the risk of transmission of SARS-CoV-2 among HCWs in the staff cafeterias of a tertiary care hospital in Seoul, South Korea from January 2020 through September 2021. The cafeteria seats were arranged on either side facing away from each other, at a distance of 30 cm, without any plastic screens. Cafeteria staff were instructed to keep a seat empty between the HCWs. The cafeterias had good ventilation and a central heating, ventilation, and air conditioning (HVAC) system with an hourly air change rate of 13 to 14.

There were 33 HCWs with COVID-19 and 119 cafeteria contacts of these index cases i.e., who ate at seats next to index case. Twenty-seven (82%) of the 33 index cases were symptomatic at the time of their diagnosis and nine (27%) were vaccinated. The contacts underwent follow-up SARS-CoV-2 RT PCR testing.

Out of the 119 contacts, three (2.5%) were diagnosed with Covid-19. When the index patients talked to their contacts while eating, the transmission risk was considerably increased compared to when they remained quiet and did not talk; 12.5% vs. 0%, respectively.

Eating in cafeterias or restaurants is a potential link in the chain of transmission of SARS-CoV-2 as masks need to be removed while eating and people have a tendency to converse during mealtime. This further propagates respiratory droplets and aerosols. It is imperative that all eating places have a good ventilation system with the recommended air changes to improve the air quality. Putting up physical barriers such as plastic sheets may not be a feasible option as they can disturb the normal ventilation.

In this study, the overall transmission rate was low (2.5%) but the transmission rate increased significantly with talking. Although the authors have recommended larger study to corroborate their findings, proper seating arrangement or even limiting seating, ensuring good ventilation and avoiding conversations may help prevent transmission of Covid-19.

With the resurgence of Covid-19, particularly the rise in Omicron cases, restrictions are back in place. Restaurants and other eating places are either closed or operating at half of their capacity. Step out of your house only when it is absolutely essential.

Stay safe and stay healthy.

Reference

1. Jung J, et al. Risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission among healthcare workers dining in hospital staff cafeterias. J Korean Med Sci. 2022 Jan 10;37(2):e14. doi: 10.3346/jkms.2022.37.e14.