[...]
Within weeks of the gathering, the Dakotas, along with Wyoming, Minnesota and Montana, were leading the nation in new coronavirus infections per capita. The surge was especially pronounced in North and South Dakota, where cases and hospitalization rates continued their juggernaut rise into October. Experts say they will never be able to determine how many of those cases originated at the 10-day rally, given the failure of state and local health officials to identify and monitor attendees returning home, or to trace chains of transmission after people got sick. Some, however, believe the nearly 500,000-person gathering played a role in the outbreak now consuming the Upper Midwest.
More than 330 coronavirus cases and one death were directly linked to the rally as of mid-September, according to a Washington Post survey of health departments in 23 states that provided information. But experts say that tally represents just the tip of the iceberg, since contact tracing often doesn’t capture the source of an infection, and asymptomatic spread goes unnoticed.
In many ways, Sturgis is an object lesson in the patchwork U.S. response to a virus that has proved remarkably adept at exploiting such gaps to become resurgent. While some states and localities banned even relatively small groups of people, others, like South Dakota, imposed no restrictions — in this case allowing the largest gathering of people in the United States and perhaps anywhere in the world amid the pandemic and creating huge vulnerabilities as tens of thousands of attendees traveled back home to every state in the nation.
Many went unmasked to an event public health officials pleaded with them to skip, putting themselves and others at risk, because they were skeptical about the risks, or felt the entreaties infringed on their personal liberties. Rallygoers jammed bars, restaurants, tattoo parlors and concert venues; South Dakota officials later identified four such businesses as sites of potential exposure after learning that infected people had visited them.
Despite the concerns expressed by health experts ahead of the event, efforts to urge returnees to self-quarantine lacked enforcement clout and were largely unsuccessful, and the work by state and local officials to identify chains of transmission and stop them was inconsistent and uncoordinated.
[...]
https://www.washingtonpost.com/health/2020/10/17/sturgis-rally-spread/
