SIOUX FALLS, S.D. — Health officials across five states have linked 178 virus cases to the Sturgis Motorcycle Rally.

In the three weeks since the rally kicked off, South Dakota health officials have reported 63 cases among rallygoers so far. The epicenter of the rally, Meade County, is reaching a per capita rate similar to the hardest-hit states of the South. Health officials in North Dakota, Wyoming, Minnesota and Wisconsin all reported cases among people who attended the 10-day rally that attracted more than 500,000 people.

Health experts are worried that large gatherings across the Upper Midwest will feed a new wave of the virus.

“This coronavirus forest fire will keep burning any human wood it can find,” said Dr. Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy. “It will find you, and it’s so infectious.”

The Black Hills region’s largest hospital system, Monument Health, says hospitalizations from the virus rose from five to 78 this month. The hospital was bracing for more COVID-19 patients by converting rooms to intensive care units and reassigning staff.