CDC: 2020 Sturgis Motorcycle Rally a COVID-19 super-spreader event
The August 2020 Sturgis Motorcycle Rally in South Dakota spread COVID-19 across the country, resulting in at least 649 infections—including transmission to household and workplace contacts—over the next 6 weeks, according to a study today in Clinical Infectious Diseases.
In the study, researchers from the Centers for Disease Control and Prevention (CDC) analyzed data and phone interview results from 39 state, county, and city health departments involving COVID-19 patients who had either traveled to Meade County in August 2020 or attended the rally from Aug 7 to 16.
The event attracted about 462,000 people from 61% of US counties, who participated in outdoor and indoor activities. No state, county, or city face covering requirements were in effect, the state had few business restrictions, and attendees were observed ignoring physical distancing recommendations.
While nine jurisdictions reported no coronavirus cases, 30 reported at least one rally-related COVID-19 infection during that period. A total of 463 primary lab-confirmed cases were reported within 2 weeks of the rally, and another 186 were identified among secondary or tertiary contacts in 17 jurisdictions.
From Aug 1 to Sept 15, the 14-day coronavirus testing volume in Meade County rose 199%, and the positivity rate climbed from 5% to 8%. Most patients (86%) had symptoms at testing or case investigation. Among the 463 primary COVID-19 patients, 3.7% were hospitalized and 1 died.
South Dakota and the bordering states of Minnesota, Montana, North Dakota, Nebraska, and Wyoming recorded 56% of all infections. Minnesota authorities traced rally-related infections to one third of the state's counties.
Of the 463 patients with primary infections, 60% were men and 84% were White. Slightly more than half of infections were in people 40 to 59 years old, while 16% were in those 60 or older.
The authors noted that the number of cases—140 per 100,000 attendees—is likely an underestimate because rally goers with no symptoms or mild illness may not have sought testing or reported attending the event, and health department resources to identify and interview contacts may have been limited.
Apr 29 Clin Infect Dis study