Sturgis biker rally adds 267,000 COVID cases and $12.2B in health costs, report says

A new study on the 80th Annual Sturgis Motorcycle Rally in South Dakota in August suggests that the event, deemed a “superspreader,” added an estimated 267,000 coronavirus cases nationwide and led to about $12.2 billion in health care costs.

The number of cases added by the 10-day outdoor event that offered dozens of concerts, races and bike shows would account for about 19% of the 1.4 million new COVID-19 infections the U.S. saw in that time frame, according to the non-peer reviewed study released this month.

As Steve Harwell, lead singer of rock band Smash Mouth, put it during his performance at the rally, “now we’re all here together tonight. And we’re being human once again. F--- that COVID s---.”

The findings highlight how large gatherings without social distancing and mask wearing work directly against America’s fight to save lives as the world awaits a vaccine.

“The Sturgis Motorcycle Rally represents a situation where many of the ‘worst case scenarios’ for superspreading occurred simultaneously: the event was prolonged, included individuals packed closely together, involved a large out-of-town population, and had low compliance with recommended infection countermeasures such as the use of masks,” researchers at the IZA Institute of Labor Economics wrote in their report.

“The only large factors working to prevent the spread of infection was the outdoor venue and low population density in the state of South Dakota.”

About 460,000 people attended the event between Aug. 7 and Aug. 16 in the city of Sturgis, which has a population of about 7,000 in a county that is home to about 26,000 people, according to U.S. Census data. However, South Dakota is “one of the least densely populated states in the country, ranking 46” out of all the states and the District of Columbia.

That’s why health experts have touted “natural social distancing” as one of the reasons why South Dakota has had low infection rates, the researchers wrote. But at the event, which brought visitors from all over the country, efforts to prevent viral spread were left to the “personal responsibility of the attendees.”

Last week, the first known coronavirus death connected to the motorcycle rally was reported in Minnesota, media outlets reported.

Using anonymous cell phone data from SafeGraph, a geospatial data platform, of 45 million devices, the researchers learned that visits from non-residents and foot traffic at restaurants, bars, retail stores, hotels and entertainment venues “rose substantially” in the area where the rally occurred and in border states.

Foot traffic rose by 90% during the event, and stay-at-home behavior dropped by about 10% in Meade County, where the event took place.

A week after the rally, the researchers found a rapid growth in COVID-19 cases in Meade. For the state as a whole, infections rose by about 35% from before the rally to after it.

Then, using that cell phone data combined with data from the Centers for Disease Control and Prevention, the team multiplied the percent of COVID-19 case increases in the counties that brought the most people into the event by the number of pre-rally coronavirus cases in each county, which resulted in an estimate of about 267,000 total cases linked to the event.

What’s more, the rally contributed to about $12.2 billion in health care costs, “enough to have paid each of the estimated 462,182 rally attendees $26,553.64 not to attend,” the report read. That price tag assumes that all cases were non-fatal and uses earlier estimates that calculated each COVID-19 case to cost about $46,000.

“This calculation is nonetheless useful as it provides a ballpark estimate as to how large of an externality a single superspreading event can impose, and a sense of how valuable restrictions on mass gatherings can be in this context,” the researchers wrote.

Pushback from South Dakota state officials

South Dakota GOP governor Kristi Noem said in a statement Tuesday that the study was “fiction,” according to the Argus Leader, and that it’s an “attack on those who exercised their personal freedom to attend Sturgis.”

“Predictably, some in the media breathlessly report on this non-peer reviewed model, built on incredibly faulty assumptions that do not reflect the actual facts and data here in South Dakota,” Noem said.

State epidemiologist Joshua Clayton said, “from what we know the results do not align with what we know,” KOTA reported.

The most current data from the state shows that 124 South Dakota residents got sick after attending the rally, according to the Argus Leader. The numbers differ because of the disparate approaches used to find ties between the event and coronavirus infections.

The state used contact tracing to find out how many people got sick as a result of the rally, whereas the study researchers depended on cell phone data to track traffic coming into the state at the time of the event and the trends in COVID-19 cases following the rally.

“We’re never going to be able to contact trace every single person from Sturgis,” Andrew Friedson, one of four authors of the study told the newspaper. “So if we want a good-faith estimate using, at the moment, the accepted statistical techniques ... this is the best number we’re going to get in my opinion.”

Dean of the Brown University School of Public Health Dr. Ashish Jha, who had no ties to the study, told the Boston Globe that the study’s estimates were “stunning” but “possible.”

“It’s possible. It’s higher than I would have expected, but given how many people were at the rally, it is possible,” Jha told the outlet.