Erik Lepisto didn't need to step inside Cowboy Jack's in mid-June to contract COVID-19. All it took was sharing a maskless car ride a day later with two people who had.

Lepisto, of Woodbury, was one of five people, including his girlfriend, riding in a car headed to Minneapolis on June 13 to protest the police killing of George Floyd. The car's driver and another passenger had been to the downtown bar — connected to 75 coronavirus cases earlier this summer — the day before.

Within a week, Lepisto, his girlfriend and the driver felt the onset of symptoms. On June 27, after two weeks and a negative test, a state health worker called the 22-year-old to tell him that he'd been infected.

"I felt I knew where I got it from," Lepisto said, noting the only time the group didn't wear masks was the half-hour they were in the car. "Before that, I was very careful. I never thought, 'Oh, they just went to the bar a day before, what if it spreads to me?' "

As the pandemic enters its ninth month and social distancing fatigue sets in, young adults, many of whom are eager to return to bars and restaurants, are driving a new wave of COVID-19 cases across Minnesota. As they fuel the surge, they're making it increasingly difficult for contact tracers to keep up with cases and track those exposed in hopes of containing the virus' spread.

"That age group is truly not seeing their role in this issue," said Carlota Medus, who heads outbreak detection teams for the state Health Department.

More people in their 20s have tested positive for COVID-19 in Minnesota than any other age group. While the virus hasn't proved as deadly for young people, health officials say they can spread it to more vulnerable groups, such as the elderly or those with health problems.

Large gatherings at pubs and restaurants create a host of problems, officials say.

Bars are ripe for rapid spread of the coronavirus as patrons, often ignoring social distancing or mask-wearing precautions, gather at close quarters, sometimes for hours, to eat, drink and socialize. With dozens of people coming and going, the risk of community spread increases, which in turn complicates efforts by contact tracers to track down all those who might have been exposed.

"The issue is the congregating. They get together and they're not maintaining that social distance," Medus said. "Then, you won't be able to identify everyone you come in contact with."

State officials aren't trying to shut down bars and restaurants, she said, but rather, simply want young adults to stop crowding them.

"It's not necessarily a setting," Medus said. "It's the behavior that goes along with that setting."

A demographic shift

State public safety inspectors in recent weeks checked more than 900 bars and restaurants across Minnesota, issuing warnings to more than a dozen establishments for violations such as workers not wearing masks or not spacing seating tables at least 6 feet apart.

According to data from the Minnesota Department of Health, more than 924 COVID-19 cases this summer have been tied to 28 bars and restaurants, with median ages of 23 or 24.

One of those was Dooley's Pub in Rochester, a popular Irish-themed sports bar that owner Tony Runkle quickly shut down after two employees tested positive for COVID-19.

Dooley's was one of six downtown Rochester establishments tied to a virus surge between June 26 and July 7, where masks and social distancing were not enforced.

In all, at least 72 customers of downtown bars tested positive and another 230 were forced to quarantine. One Dooley's patron was hospitalized. The median age of those who tested positive was 25.

"You can't control the 25-year old's response," said Runkle, who decided to close the bar for at least a month because of the pandemic and road construction.

Officials said Dooley's was publicly identified and singled out by the state health department because at least seven cases were linked solely to the bar, increasing the risk to the public and making the ability to trace cases exponentially more difficult. But Runkle said his staff was trained and wearing masks. And he's installed plexiglass between server stations, removed tables and instituted strict disinfecting protocols.

"There's people that tested positive, they don't care," he said. "They go out anyway. It's a sad thing. And the businesses suffer the consequences."

The Mayo Clinic's Dr. Ravindra Ganesh has seen a decided shift from the early days of the coronavirus pandemic, when mostly older people were becoming infected. Contact tracing was successful because people were scared. Now, the public is weary. Young adults are less frightened of getting sick and, in some cases, feel they are being scapegoated.

Mayo Clinic is unable to follow up with about 30% of positive cases involving young adults, he estimated. It's a new and dangerous reality.

"We just can't get ahold of them at all. That's a problem," Ganesh said. "They don't answer their phones very well."

Tracking the virus

Each morning, Franny Dorr logs on to the computer in her St. Paul home and, coffee cup in hand, calls up the names of Hennepin County residents recently diagnosed with COVID-19. Every day, the state sends a list of 50 new names for teams of about 20 contact tracers to call. Young adults who have attended parties or been to bars, Dorr said, "are sometimes a little more difficult to get on the phone."

So Dorr has taken to sending out an extremely generic text message: "This is Franny from Public Health. Could you give me a call back?"

The medical detectives first call people who have tested positive, asking for the names and numbers of friends, family and co-workers they were near. Dorr said those infected are most likely to spread the virus to others a couple of days before symptoms start.

Tracers then call the people who have been exposed to those who tested positive and try to persuade them to self-quarantine or get tested.

If the infected person was working, the tracers want names of co-workers. If the person shares a home, tracers want to know the roommates. If the person attended a party, tracers push for the name of the organizer and a guest list. Sometimes, there's pushback.

"Maybe they feel they shouldn't be doing that, or they're nervous they or the organizer will get in trouble," Dorr said.

Sometimes, tracing hits a dead end.

"Some people answer on the first call. Some people we never get ahold of," Dorr said. After 10 days of unanswered calls and texts, tracers give up.

Andrew Murray, another Hennepin County epidemiologist, talked with a young man who first felt sick around Mother's Day. He nonetheless attended an indoor Mother's Day family gathering that involved 25 people. That led to a lot of follow-up phone calls.

"We recommended quarantine for two weeks from Mother's Day," Murray said. "That's a big ask for 25 people."

Murray, who has been with Hennepin County almost four years, handled tuberculosis cases before COVID. Most people want to help and are forthcoming about where they were and who they were with, he said. Sometimes they need coaxing, especially the younger crowd.

"It's trust-building and it's being really open about why you're asking for that information," he said. "We can't be looking at it for blaming somebody. That's not what we're trying to do."

jim.walsh@startribune.com 612-673-7428

jackie.crosby@startribune.com 612-673-7335