Covid-19 Cases Surge in 460 Counties Sturgis Riders Hailed From

It’s been just over a month since hundreds of thousands of largely unmasked motorcycle riders descended on the small town of Sturgis, S.D., raising fears the event would become a “superspreader” of the coronavirus.

Now, new testing numbers combined with cellphone location data show those fears may have been well-founded.

More than 460 counties nationwide where bikers originated from and Covid-19 cases were trending downward before the rally have shown increases in the virus, a Bloomberg Industry Group data analysis shows.

More than two-dozen counties in South Dakota, Minnesota, Iowa, and Texas flipped in such a manner, while significant numbers of counties in states as far away from the Dakotas as North Carolina, California, and Louisiana also made the list.

Cell phone data gathered by research firm Safegraph and subjected to further analysis by Bloomberg Industry Group shows that from Aug. 7 through Aug. 16—the dates of the Sturgis rally—visitors came from nearly every state in the nation, originating from more than 1,600 separate counties and nearly 6,000 census block group areas. (The data comes from a representative sample of cell phones and tracks movement based on where the phone was located.)

Coronavirus infection records from Johns Hopkins University were used to calculate which U.S. counties had showed decreases in infection rates during the 14 days prior to the start of the rally and the 14 days after the rally ended. In more than 460 counties nationwide, cases that had been trending downward before Sturgis were on the rise, the Bloomberg Industry Group analysis showed.

As of Tuesday, in South Dakota’s neighbor Minnesota alone, there had been at least 51 new cases of the coronavirus officially tied to the rally, and one death, according to Julie Bartkey, a spokesperson with the Minnesota Department of Health. While Bartkey declined to comment further on Sturgis, she said it was clear “large crowds continue to be a conduit for transmission and we encourage everyone to remain vigilant in mask wearing, social distancing and other safety measures.”

Health officials in nearly a dozen states have tied new cases directly to the rally in recent weeks. Once exposed to the virus, symptoms can generally appear anywhere from two to 14 days later, according to the Centers for Disease Control and Prevention, meaning there has been ample time to measure the impact of the wildly popular rally on public health.

Despite calls to cancel the annual event, nearly a half-million people rode into Sturgis, most not wearing masks or practicing social distancing, according to video shot from the event. The top states as a percentage of the Sturgis visitors where riders came from outside of South Dakota itself were Colorado, Minnesota, Texas, and Nebraska, but the data shows attendees originated, and returned to, virtually every state in the country.

City officials in Sturgis defended the decision to go forward with the rally.

“The City continues to hold those infected with COVID in our thoughts and prayers,” said Sturgis City Manager Daniel Ainslie in a statement. “However it is important to note that fewer than 300 individuals have had positive infections after reporting trips to Sturgis. Furthermore, this does not mean that they actually were infected while in Sturgis. Though these individuals are valued, it is a mere fraction of the number that was projected and anticipated by many of the experts.”

Ainslie said he believed most bikers planning on coming to the annual rally would have come to Sturgis even if the city canceled festivities, as some had proposed.

Meade County, S.D., where Sturgis is located, had 87 coronavirus cases reported among local residents when the rally began on Aug. 7, a slight upward trend on its moving average at the time. But as of Sept. 4, that number had nearly quadrupled to 332 known cases.

Both North Dakota and South Dakota have experienced surges in coronavirus cases in recent weeks with the states reporting some of the highest rates for people testing positive for the virus in the nation.

On Tuesday, concerns about the Sturgis rally spreading the virus were amplified by the release of a study by the IZA Institute of Labor Economics in Germany that attempted to statistically model the potential spread, estimating upwards of 250,000 new infections could tie back to the Sturgis rally.

That study came under immediate criticism from South Dakota’s governor as being too speculative and has not yet been peer-reviewed by other social scientists.

The Bloomberg Industry Group analysis did not try to forecast or determine exactly how many current cases Sturgis is responsible for, either in those 460 counties or elsewhere.