This archive report was first published on 13 May 2020.
On March 10, 2020, a group of 61 singers from the Skagit Valley Chorale met for choir practice at their church in Mount Vernon, Washington. The practice was a typical Tuesday night gathering, but it would soon become a significant event in the COVID-19 pandemic.
One of the singers had been experiencing cold-like symptoms for a few days prior to the practice and later tested positive for the coronavirus. Within two days, six more members of the choir developed a fever, and ultimately, 53 members of the choir became ill with COVID-19, with two fatalities.
The outbreak was first reported by the Los Angeles Times in March 2020 and demonstrated the contagious and deadly nature of the coronavirus, particularly among older populations. The median age of those attending the practice was 69.
A study conducted by the Skagit County health department, led by Dr. Howard Leibrand and Dr. Lea Hamner, found that swift action by the choir members, including voluntary isolation, and contact tracing by the health department, helped contain the spread and prevent a larger outbreak in the community.
Dr. Leibrand noted that if the choir members had not initiated their own isolation and quarantine, the outbreak could have been much worse, with potentially every infected person infecting three others, leading to a significant increase in the infection rate.
The study highlighted the dangers of indoor gatherings, particularly for activities like singing that can facilitate transmission. The choir practice, which took place in a large room with seats packed together, six to 10 inches apart, was a fertile ground for transmission.
Dr. Hamner and Dr. Leibrand praised the choir members for their cooperation and diligence in maintaining self-quarantine and providing useful information that aided the investigation.
As communities begin to ease restrictions on movement and gatherings, the Skagit County choir outbreak serves as a warning about the dangers of indoor gatherings, particularly for activities that can facilitate transmission.
