On March 10, three days before the White House declared COVID-19 a national emergency, an individual attended a choir practice in Mount Vernon, Washington.
Usually, the choir group was attended by around 122 people at the Mount Vernon Presbyterian Church.
But amid growing fears around the pandemic, only 61 turned up.
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At the time of the practice, there were no known cases of COVID-19 in the Mount Vernon area. But when the individual, now referred to as a “super spreader” attended the choir, they had developed some mild cold-like symptoms.
In a case which has now been researched by infectious disease specialists, the choir group had a 40-minute mass practice, followed by a 50-minute practice in two smaller groups. In the two groups, one group sat in a smaller room on benches, while the other group gathered in a larger room while sitting in chairs in a tight cluster.
After a 15-minute break, which included a shared snack of cookies and oranges, the two groups reconvened for another 45-minute mass practice, before the choir members headed home.
Throughout the practice, the choir members followed a few precautions, such as not hugging or shaking hands. However, they didn’t all follow further social distancing measures, such as remaining at least 1.5 metres apart. While gathered for the mass practices, for example, the choir members sat around 15-25 centimetres apart.
Within just days of the practice, a few members began showing symptoms of COVID-19.
Finally, within 12 days of the practice, 52 out of 61 attendees had contracted the disease. That’s 86.7 per cent of the attendees.
Although most of the patients, who were largely older women, did not have any underlying conditions, three members with underlying health problems were hospitalised.
Of those three patients, two later died.
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What is a super spreader?
As per The Independent, a super spreader is a patient who infects significantly more people with a disease than usual.
Since the COVID-19 pandemic began, doctors have generally maintained the number of people one person with coronavirus will infect is on average two to three people.
But because this is just an average, a small number of patients are known to infect others far more or less.
As Mark Woolhouse, a professor of infectious disease epidemiology told The Independent: “With a super spreader you are just seeing the tail end of that [average] distribution pattern.”