The Sturgis Motorcycle Rally might be rolling into the record books as the largest known coronavirus super-spreader event in the U.S. to date.
A new study that analyzed cellphone pings for rally attendees and the COVID-19 case numbers in the communities they returned to estimates that more than 265,000 infections confirmed between Aug. 2 and Sept. 2 trace back to the massive gathering of motorcycle enthusiasts in South Dakota.
“We found that for counties that had a lot of people going to Sturgis, after the rally, their case numbers starting taking off relative to similar places that did not have a lot of people going to Sturgis,” Andrew Friedson, an economics professor at the University of Colorado Denver and one of the study’s authors, told the New York Daily News Tuesday.
He said the 266,796 cases of COVID-19 linked to Sturgis represent 19% of the 1.4 million new coronavirus cases confirmed in the U.S. during the study time frame.
“To my knowledge, this is the largest single super-spreading event. I don’t know of anything larger,” he said. “The only thing that would come close might be a study done after Spring Break. But that was not a single event.”
The rally that drew hundreds of thousands of attendees from all over the country has officially been linked to hundreds of coronavirus cases in several states and at least one death.
The new research report from the IZA Institute of Labor Economics and affiliated with the Center for Health Economics & Policy Studies at San Diego State University said the 10-day rally that started Aug. 7 drew more than 460,000 people to a South Dakota city with a population of only 7,000.
“We find that counties that contributed the highest inflows of Sturgis attendees saw COVID-19 cases rise by 10.7% following the Sturgis event relative to counties without any detected attendees,” the 63-page report said.
“We conclude that the Sturgis Motorcycle Rally generated substantial public health costs, which we calculate to reach at least $12.2 billion,” it said.
“The estimates in this paper, if confirmed, would place Sturgis as the largest studied super spreading event in U.S.,” Dr. Scott Gottlieb, a former Food and Drug Administration commissioner now at the American Enterprise Institute, said in a Twitter post Tuesday.
According to the report, more than 90% of Sturgis attendees this year came from outside South Dakota, with 18.6% driving in from border states and 72.1% traveling from the remainder of the country.
Media reports and photographs showed scenes with minimal mask wearing and social distancing.
South Dakota Gov. Kristi Noem blasted the research report in a series of Twitter posts Tuesday.
“This report isn’t science. It’s fiction. Under the guise of academic research, it’s nothing short of an attack on those who exercised their personal freedom to attend Sturgis,” she tweeted.
“At one point, academic modeling also told us that South Dakota would have 10,000 COVID patients in the hospital at our peak. Today, we have less than 70,” she said.
“Her criticism is that we are doing models, and that’s not what this is,” Friedson told the Daily News.
“We’re looking at actuals — and we’re making some assumptions if a place sent a lot of people to Sturgis,” he said.
“If there’s a break from the common trend, we’re assigning it to Sturgis,” he explained. “You can say you don’t believe it, but calling this a model-based fantasy is a lack of understanding science.”
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