Skagit Chorale COVID-19 outbreak study published by CDC

The March Skagit Chorale COVID-19 outbreak has made headlines around the world. A study by Skagit County Public Health Department staff was published in the Centers for Disease Control’s Morbidity and Mortality Weekly Report (MMWR) in early May.

The study emphasizes the high-transmissibility of COVID-19 and explains new findings about the outbreak event.

MMWR, often called ‘the voice of the CDC,’ is a series of scientific publications published by the CDC to provide timely, authoritative, accurate, objective and useful public health information and recommendations.

“Washington State has been on the front line of the COVID-19 outbreak in the U.S., and it’s an honor to be able to provide timely research to help inform (citizensabout) the work of public health officials nationwide,” said Jennifer Johnson, Skagit County Public Health Director, “The Skagit Chorale outbreak was a horrible tragedy, and many reached out to us hoping to learn from this experience. Hopefully this report’s findings will keep a tragedy like this from happening anywhere else in the United States.”

“I want to personally thank the Chorale group members, who were helpful and kind throughout this investigation,” said Public Health Officer Dr. Howard Leibrand. “We are so thankful they were willing to share their experiences with us and appreciate their early recognition of the issue and clear communication with members and Public Health to mitigate further impacts.”

The full report is on the CDC’s website. A summary is on the County’s website.

The report details 52 of the 61 people at the 2.5-hour choir practice contracted COVID-19 from a symptomatic index patient, 32 who were confirmed and 20 probably secondary. Three were hospitalized, and two died. Transmission was likely facilitated by close proximity (within 6 feet) during practice and augmented by the act of singing.

This cluster of 52 secondary cases of COVID-19 was termed a unique opportunity for study in the report.

“Superspreading events are a serious concern during this COVID-19 pandemic,” said Lea Hammer, Communicable Disease and Epidemiology Lead for Skagit County Public Health and primary author. “Few superspreading events have been researched and traced to a community gathering. Because we were able to identify a single event from which many got infected, this event provides us with unique insight into how COVID-19 spreads.”

“If we have learned anything from this event, it’s that social distancing is absolutely vital to protecting ourselves and our community,” said Polly Dubbel, Skagit County Public Health communicable disease and environmental health manager. “It is recommended that people not gather in groups, stay six feet apart from each other and avoid crowded places to reduce transmission. This study highlights just how important those recommendations are.”

Skagit County Public Health notes it is a state leader in contact tracing, disease investigation and testing capability. Information: 360-416-1500.

At the end of May the CDC removed its guidance for limiting choir activities at houses of worship from its website, since the White House had not approved the wording.

Source: Skagit County Public Health