As Switzerland reopens, the details around how SARS-CoV-2 spreads becomes more relevant to everyday life.
Matthias Egger, the head of Switzerland’s Covid-19 task force, stresses the importance of continuing to follow social distancing and hygiene rules.
However, the Swiss government’s recommended rule of staying two metres away from the next person might not be enough if the next person is singing.
Infection requires a minimum amount of virus. It is possible to get some virus and not succumb to the disease. Different activities release different concentrations of viral particles and send them different distances. If you are around an infected person, whether you become infected depends on how much virus they release, how far it travels, how long you spend with them, and other things like air flow and the air refresh rate.
Virologists warn that singing forces out droplets, so they travel further. In addition, some believe singers could absorb many more virus particles as they tend to breathe deeper into their diaphragms than they would during normal breathing. Wind instruments are also a concern.
Reports in Washington, where three-quarters of the members of one choir fell ill, and in Berlin, where the same percentage of singers from a cathedral choir in Berlin caught the virus, provide anecdotal evidence that singing in choirs contributes to the spread of SARS-CoV-2, the virus causing Covid-19.
Lothar Wieler, the head of the German government’s disease control agency, warned against singing. “Droplets fly particularly far when singing” he said, in a broadcast on Germany’s RTL.
In the Washington example, a single asymptomatic choir singer infected three-quarters of the choir during a 2.5 hour rehearsal in a small church.