SEATTLE – Spring brought a wave of cancellations that shut down professional baseball, basketball, concerts, movie theaters, youth sports, school plays, camping in state parks and all sorts of other events to slow the spread of the novel coronavirus.
Then, on May 25, came the brutal death of George Floyd as a Minneapolis police officer held a knee to his neck, an act of violence that set off large protests in a powerful grassroots justice movement that also unfolded as a kind of mass experiment about the risks of such outdoor gatherings amid a global pandemic.
More than one month after Floyd’s death, the number of COVID-19 cases is rising in some parts of Washington state, including the Seattle area, and the national tally of new cases last week reached all-time highs.
But some researchers say that the protests do not appear to be significantly driving this surge. This helps bolster the case that the coronavirus generally does not transmit as easily outdoors, where even a gentle breeze can help diffuse the virus, compared to confined indoor spaces.
“I would say that outside makes a big difference because of much more air circulation,” said Dr. Jared Baeten, a vice dean at the University of Washington’s School of Public Health, who donned a mask and joined in the June 12 March of Silence through Seattle that drew an estimated 60,000 people.
In King County, the epicenter of Washington’s protests, health investigators have tracked – during a 19-day span in June – less than 5% of 1,008 total positive cases to people who attended protests. In other cities, including Minneapolis and Portland, researchers have yet to find that protests, where many were masked, have caused major spikes in cases.
“The data may be imperfect but ... neither here in King County, or elsewhere in the county, where health care authorities are looking, have we been able to document that or find strong evidence of that,” said Dr. Jeffrey Duchin, health officer of Public Health – Seattle & King County in remarks to reporters on Friday.
Others have reached a similar conclusion.
A working paper – yet to be peer reviewed – from the National Bureau of Economic Research analyzed data from protests in 315 large cities and found “no evidence that urban protests reignited COVID-19 case growth during the more than three weeks following the protest.” The study also cited evidence that protests prompted more stay-at-home behavior by those who didn’t go to the protests.
Still, some public health officials offer a more skeptical view.
In Los Angeles, where COVID-19 cases are escalating, Barbara Ferrer, the Los Angeles County Public Health Director, said it was “highly likely” that the surge is connected, in part, due to the protests, although there was no tracking of such cases, according to the Los Angeles Times. Also in Los Angeles, police officials report that the rate at which officers are contracting the virus has been on the rise, and are trying to determine whether the protests might be a source of infection.
Most of the Seattle protests unfolded during June, a month that early on continued to show a weeks-long decline in the seven-day average number of new cases. Then, during the second half of the month, which included the June 19 resumption of dining in restaurants as the county moved into Phase 2 reopening, the case trended upward.
In his Friday briefing, Duchin reported a 60% jump in new cases during the June 14-20 time frame compared to the previous week.
Duchin said that the ages of those infected is trending younger, and that there appeared to be a wide range of factors driving the infections, including people living with someone else who is infected. Some of the increase also may be the result of increased testing rates, which since June 11 had doubled from 15,000 per 100,000 county residents to 30,000, with a big chunk of that testing in Seattle, where many of the new cases have emerged.
And Duchin noted that the rate of positive infections – a key indicator of the spread of the coronavirus – has not risen.
The numbers of protesters who test positive for the coronavirus was determined through contact tracing, which involves asking infected people about the places they have been. The goal is to understand where they may have been exposed – and who else they may have exposed.
As of June 24, contract tracing had determined only 31 COVID-positive people attended protests out of 1,008 who tested positive between June 3 and June 23.
This contact tracing does not reach all infected individuals who may have gone to protests. That’s because some may be asymptomatic and not know they have the infection and never go in for testing, while others – even with symptoms – may be reluctant to get the tests. And Dr. Judith Malmgren, an epidemiologist and affiliate assistant professor with the University of Washington, said some people, when contacted by tracers, may not want to disclose that they went to protests.