One COVID-19 cluster of aerosol transmission?
March 31, 2020
There has been a lot of interest in the ways in which spread. In one incident, there was a cluster of COVID-19 among people participating in a choir practice. Sixty people reunited on March 10 for a choir practice in a small town in the north west of the United States. It is important to note that at that time, the county did not report any COVID-19 case, and public gatherings were not prohibited yet. Everybody followed strict rules, refrained from physical contact and used hand sanitizer. None of them showed any symptoms, according to 8 of the participants. A few days later, few of them were reporting symptoms, and in a three-week period, 45 have been diagnosed with COVID-19.
This event, among others, adds fuel to the scientific debate about the ways in which spread can occur, and the ways in which transmission could be prevented. Gatherings of large groups of people are recognized as an opportunity for transmission to occur, and we have a number of examples of larger clusters in Hong Kong. If possible these events should be postponed or cancelled. If gatherings need to go ahead perhaps transmission would be less likely to occur if everybody wore a mask. One of the good reasons for everyone to wear masks is that it could prevent asymptomatic carriers from infecting others. In a recent study, Professor Cowling and other scientists reviewed the face mask recommendations from different countries. Dr Feng, first author of the study, explained that one of the common reasons that mask wearing was not recommended in the general community in some locations might be the lack of supply, and the need to prioritise masks for health workers.
Here are some news articles discussing this issue in English:
Here are some news articles discussing this issue in Chinese: