Singing COVID-19 ‘superspreader’ infected dozens at choir in Washington, CDC says

On March 10, as the coronavirus began to emerge in the U.S., a church choir gathered for practice in Mount Vernon, Washington.

It was two weeks before stay-at-home orders were issued in Washington state, and one of the 61 choir members in attendance didn’t feel well and was exhibiting coronavirus symptoms, the Associated Press reported.

Within one or two days, at least six members developed a fever, according to a report released Tuesday by the Centers for Disease control.

More choir members became ill with COVID-19 over the next two weeks, making the the choir practice one of the first “superspreader” events in the U.S., according to the CDC report.

“One individual present felt ill, not knowing what they had, and ended up infecting 52 other people,” Lea Hamner, lead author of the CDC’s report, said, according to the Seattle Times.

Two of the choir members died and three were hospitalized, according to the CDC report. The vast majority of the patients were 65 years or older and all three hospitalized patients had two or more underlying health conditions, the CDC says.

A superspreader event is when, at a large gathering of people, one person — known as a “superemitter’”— spreads the disease to others, according to WebMD. The CDC takes it step further, saying the superemitter is a person who releases more aerosol particles when speaking than the average person, the CDC says.

The singers sat 6 to 10 inches apart at the 2 1/2 practice, the Times reported. In that time, choir members shared snacks and helped stack chairs, but the CDC believes singing helped the spread as well, according to US News.

“The act of singing, itself, might have contributed to transmission through emission of aerosols, which is affected by loudness of vocalization,” the CDC report says.

The most common symptoms among the choir members were cough, fever, myalgia and headache, the CDC says.

“This outbreak of COVID-19 with a high secondary attack rate indicates that SARS-CoV-2 might be highly transmissible in certain settings, including group singing events,” the CDC report says. “This underscores the importance of physical distancing, including maintaining at least 6 feet between persons, avoiding group gatherings and crowded places, and wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain during this pandemic.”

This story was originally published May 13, 2020 at 1:57 PM with the headline "Singing COVID-19 ‘superspreader’ infected dozens at choir in Washington, CDC says."