Disease trackers are calling a choir practice in Washington State a “superspreader event” that underscores the highly contagious nature of the deadly bug that causes COVID-19.
After 61 people attended a 2.5-hour choir practice in Skagit County on March 10, there followed 32 confirmed and 20 probable infections of COVID-19, with three sufferers ending up in hospital and two dying, according to a report from Skagit County Public Health published Tuesday.
Titled “High SARS-CoV-2 Attack Rate Following Exposure at a Choir Practice,” the report shows how easily the Chinese Communist Party (CCP) virus, the novel coronavirus that emerged from China last year and causes COVID-19, can pass from person to person.
“One individual present felt ill, not knowing what they had, and ended up infecting 52 other people,” said lead author Lea Hamner, calling the outbreak a tragedy.
The act of singing itself may have spread the virus in the air and onto surfaces, the report noted, and put the CCP virus “attack rate” at between 53.3 percent and 86.7 percent.
The singers sat 6 to 10 inches apart in different configurations during the rehearsal at a church in Mount Vernon, Washington, about 60 miles north of Seattle, according to the report.
Choir members had no physical contact, although some snacked on cookies and oranges or helped stack chairs, they told investigators. The virus could have spread when exhaled droplets landed on those items.
Another theory put forward in the report is that the fine mist of virus particles emitted during singing may have accelerated the spread of the deadly bug.
The virus is thought to primarily spread through droplets when an infected person coughs or sneezes.
The singers felt their first symptoms—cough, fever, muscle pain, or headaches—one to 12 days after the practice. The sick singers’ average age was 69 and most were women.
“The potential for superspreader events underscores the importance of physical distancing, including avoiding gathering in large groups, to control spread of COVID-19,” the report concluded.
The Centers for Disease Control and Prevention (CDC) recommends avoiding large groups, wearing cloth masks in public, and staying at least 6 feet apart from others.
“Enhancing community awareness can encourage symptomatic persons and contacts of ill persons to isolate or self-quarantine to prevent ongoing transmission,” the report authors noted.
But while understanding how the virus spreads is important for preventing and tracking the disease it causes, there is still much to learn, according to Dr. Anthony Fauci, member of the White House coronavirus task force.
Fauci, in Senate testimony Tuesday, cautioned against jumping to conclusions about a virus with respect to which the scientific community still has blind spots.
“We don’t know everything about this virus,” said Fauci, who also serves as director of the National Institute of Allergy and Infectious Diseases. “And we’d really better be very careful, particularly when it comes to children.”
Fauci then referred to a rare inflammatory syndrome believed to be linked to COVID-19, which has killed at least three children in New York and afflicted dozens of others. The syndrome shares symptoms with toxic shock and Kawasaki disease, which can cause inflammation of arteries of the heart.
“You’re right in the numbers that children, in general, do much, much better than adults and the elderly and particularly those with underlying conditions,” Fauci said, responding to remarks by Sen. Rand Paul (R-Ky.) about reopening schools in the fall, adding, “But I’m very careful—and hopefully humble—I don’t know everything about this disease and that’s why I’m reserved in making broad predictions.”
As discussions continue about when it is safe to reopen schools in the face of the pandemic, several studies suggest children are not only less susceptible to COVID-19 infections but may also be far from the silent “super-spreaders” some fear they may be.
Icelandic scientist Kári Stefánsson, who studied the spread of COVID-19 in his country, told Science Museum Group in an interview in April that his research revealed not a single case of a child in Iceland infecting his or her parents.
“Children under 10 are less likely to get infected than adults, and if they get infected, they are less likely to get seriously ill,” Stefánsson said in the interview, which took place shortly after the publication of the study he co-authored in The New England Journal of Medicine. “What is interesting is that even if children do get infected, they are less likely to transmit the disease to others than adults. We have not found a single instance of a child infecting parents.”
If the Icelandic conclusions are sound, it would suggest that children may not be at high risk of infection from exposure to one other. The conclusions also imply that teachers may similarly be less likely to catch the virus from their students.
The Associated Press contributed to this report.