Atlanta – Distance rules are difficult to enforce in restaurants or bars. It is not possible to cover the mouth and nose when eating food. According to the results of a case-control study, the consequence is in Morbidity and Mortality Weekly Report (MMWR 2020; 69: 1258-1264) an increased risk of infection.
Since the end of the lockdown, the number of infections has risen again in many countries. There are different ways for the population to become infected. What is important in practice can be determined with case-control studies that compare infected and non-infected people.
Kiva Fisher von den Centers for Disease Control and Prevention (CDC) from Atlanta and employees interviewed 314 adults who had come to a test for SARS-CoV-2 with possible symptoms of COVID-19: 154 had positive results, the other 160 people were not infected.
Both groups were asked about wearing a mask and about possible risk contacts, for example whether they had been shopping in the last 14 days, whether they were in smaller or larger groups of people or whether they worked in an office with other people. Other questions related to visits to fitness studios, the use of public transport, visits to churches and staying in restaurants and bars / cafes.
There were only significant differences when visiting restaurants and bars. The infected had visited these locations twice as often as the controls. For dining out, Fisher determined an adjusted odds ratio of 2.4, which was significant with a 95% confidence interval of 1.5 to 3.8.
No significant difference was initially found for visits to bars and cafés. This changed when the analysis was limited to people who otherwise had no contact with SARS-CoV-2 infected people. The adjusted odds ratio then increased to 3.9 (1.5 to 10.1). Fisher determined an adjusted odds ratio of 2.8 (1.9 to 4.3) for the visitors to restaurants who could not remember an encounter with the infected.
The infected persons stated significantly more frequently that no or only a few other guests had worn mouth and nose protection when visiting the restaurants (19.0 versus 2.3%). This was the case even more frequently with bar visits (31.8 versus 25.0%). The differences were significant in both cases.
The study thus shows that visiting restaurants and bars is associated with a potential risk of infection. How big it is depends heavily on the mask discipline of the other guests. © rme / aerzteblatt.de