Fifteen Minnesotans who attended the Sturgis Motorcycle Rally this month have tested positive for the novel coronavirus, including one state resident hospitalized with COVID-19, state health officials say.

The Minnesota Department of Health received the first case report on Thursday and 14 more case reports on Friday, said Kris Ehresmann, the state's director of infectious diseases, during a briefing Friday with reporters. Minnesotans who tested positive visited multiple campgrounds and bars at the South Dakota event, Ehresmann said, so cases apparently can't be connected to any one location.

Seven residents of North Dakota also have cases connected to the Sturgis event, a government spokesman told the Star Tribune.

"Thousands of people attended that event, and so it's very likely that we will see more transmission," Ehresmann said.

The 10-day Sturgis Motorcycle Rally drew more than 460,000 vehicles this year, according to state officials. In the days leading up to the event near Rapid City, health officials in Minnesota expressed concern about the potential for the virus to spread at large indoor/outdoor gatherings like the Sturgis rally.

South Dakota officials, on the other hand, encouraged the event in a state that doesn't mandate the use of masks. There have been fewer than 25 cases associated with the rally, said Rebecca Piroutek of the South Dakota Department of Health in an e-mail.

The department has issued three public health notices thus far for business exposures related to the rally, Piroutek said. Notices are issued, she said, when an individual is unable to identify people they were in close contact with while able to transmit the virus.

Word of cases linked to Sturgis came as Minnesota reported eight more deaths from COVID-19 and a relatively high number of newly confirmed infections.

The Health Department reported a net increase of 825 new coronavirus cases, according to data released Friday morning, on a volume of 18,815 completed tests. In the past week, the state averaged 630 new cases per day on a volume of about 17,300 tests.

About 4% of tests have been coming back positive this week, which is a lower rate than Gov. Tim Walz has suggested might trigger further restrictions to control the spread of the novel coronavirus. But health officials are cautious about the relatively high number of new cases among people infected in the community without a known exposure — another key measure.

With the virus still circulating, health officials have been cautioning college students to "lay low" so they don't unwittingly bring COVID-19 back to campus as they return to school this fall. On Friday, the state extended the message to K-12 students, encouraging families to follow social distancing recommendations, wash hands and stay home when sick.

The goal is to avoid problems seen in states like Georgia, where hundreds of school staff either tested positive or were exposed and couldn't participate in back-to-school activities, said Susan Klammer, an epidemiologist with the Minnesota Department of Health.

"As we get within that window of two weeks before the start of school, we're really asking that you avoid settings with a high risk of transmission," Klammer said. "It's a good way to reduce your risk of picking up COVID and introducing it to your school, which as we've seen can be a real problem."

For people who went to Sturgis, it's best to self-quarantine for 14 days, Ehresmann said. People who are feeling ill should get tested, she said, and self-isolate while waiting for results.

Fourteen of the Minnesota cases were among attendees of the rally, Ehresmann said, while one worked temporarily at a Sturgis bar that hosted events. The event ran Aug. 7-16.

"Obviously, it takes a while for people to develop symptoms and to get tested and for us to get those results," Ehresmann said. "So, we do anticipate that these won't be the only cases that we see."

Due to COVID-19 concerns, the city of Sturgis announced modifications before the rally, which draws motorcycle riders from across the county. City-sponsored events including parades, contests and live music were canceled, according to the city's website.

City officials did not immediately respond to questions via e-mail.

On Friday, the latest COVID-19 numbers in Minnesota showed 296 patients were hospitalized, down 13 from Thursday's data release. The tally for ICU patients dropped by 12 to 136 patients.

Daily counts for hospitalized patients in Minnesota have been holding steady in recent weeks and well below peaks of more than 600 hospitalized patients and about 260 in the ICU in late May.

Residents of long-term care and assisted-living facilities accounted for four of the eight deaths newly announced by the Health Department. Statewide, 1,753 people have died from the virus, including 1,302 deaths in long-term care or assisted-living residents.

COVID-19 is a viral respiratory illness caused by a new coronavirus that was found circulating late last year. Since the first case was reported in Minnesota in early March, hospital stays have been required in 6,064 cases.

People at greatest risk from COVID-19 include those 65 and older, residents of long-term care facilities and those with certain underlying medical conditions.

Most COVID-19 patients aren't hospitalized, but experience mild or moderate illness. Many who are infected don't show symptoms.