Testing has identified a second COVID-19 case in Minnesota — this time in a Carver County resident who was likely exposed to the coronavirus that causes the illness while traveling in Europe late last month.

The Minnesota Department of Health announced the second case on Sunday evening, just hours after the test result at the state's public health lab. The patient, in the 50-59 age group, is recovering at home after developing symptoms on March 2 and seeking health care on Saturday.

While both positive tests in Minnesota are considered presumptive until they are confirmed by the U.S. Centers for Disease Control and Prevention, the Health Department's epidemiologists are already launching an investigation to find out who had been in contact with the Carver resident and may now be at risk for infection.

"These presumptive results are considered actionable, which means we are working with the patient and identifying contacts," said State Health Commissioner Jan Malcolm.

Minnesota's first case was confirmed through testing on Friday and involved a person 65 or older who lives in Ramsey County. That person was likely infected last month while aboard the Grand Princess cruise ship, which has now been docked off the coast of California because of COVID-19 cases among the passengers and crew. Forty-two Minnesotans are among the 3,500 passengers who have been placed in quarantine on that ship.

Both of Minnesota's first two COVID-19 cases were associated with travel and involved people who were exposed outside of the state. That allows the state Health Department to continue with a containment strategy of working to prevent or slow the spread of the novel coronavirus in Minnesota, said Kris Ehresmann, state infectious disease director. That becomes tougher when the virus is spreading from person to person within a community or state — as has happened in Washington and California.

"Although there are many locations in the United States that have moved to community mitigation, where they are canceling large events, where they are temporarily canceling school … in Minnesota, we are still at the point where we're focusing on containment," Ehresmann said.

A key first step is for the Carver patient to agree to self-isolation at home while still infectious. Carver County Public Health officials will offer support to the individual. Next, health officials must find out who had been in proximity to the individual and might need to be quarantined for 14 days to make sure they aren't infectious as well.

In the first Ramsey case, health officials found the patient hadn't been in close contact with others. The Carver investigation is just getting started, so Ehresmann said she didn't know if that patient had been in contact with others.

Ehresmann said that contact investigations for COVID-19 are more focused than for investigations of more infectious viruses such as measles, which can linger in the air. Health officials will be identifying people who have been within 6 feet of the Carver patient for at least 10 minutes, because the most likely method of transmission is a sick person sneezing or coughing up droplets that land on others nearby.

"We're not worried about that airborne spread," she said. "We're not worried about people who just walked past them at the grocery store."

While other coronaviruses cause common colds, the new virus that emerged in China in December is concerning because nobody has immunity to it. The state Health Department said that, as of Sunday, there have been more than 107,700 confirmed COVID-19 cases globally and 3,600 deaths. In the U.S., more than 500 cases have been confirmed and 21 people have died.

The rapid spread of the outbreak in Italy has caused the shutdown of schools and quarantine measures restricting roughly one quarter of that nation's population. State health officials declined to identify where in Europe the infected Carver patient had been traveling, or provide the patient's name or other details for privacy reasons.

Minnesota had been sending samples from suspect cases to the CDC until March 2, when it started conducting its own testing. Both positive tests came from 80 samples tested last week at the state public health lab.

More information about coronavirus can be found on MDH's Coronavirus website. MDH has set up a public hotline that will be open 8 a.m. to 4:30 p.m. Monday. The hotline number is 651-201-3920.

Malcolm said the state needs Minnesotans to help reduce the spread of the coronavirus: "Stay home when you are sick. Cover your cough when sneezing. Wash your hands frequently and well."

In both confirmed cases, patients waited several days after experiencing their first symptoms before seeking health care. Ehresmann said people should not seek medical care any earlier than they would in any other flu or cold season, but they should remain at home and stay out of work or school while they have fever and respiratory symptoms. Patients also should call ahead to clinics, which can then take steps to reduce the threat of infection to staff or other patients.

"We don't want people to feel just because COVID is circulating that they need to seek health care" that they otherwise wouldn't, she said.

State health officials had no update Sunday about the status of the 42 Minnesotans under quarantine on the Grand Princess cruise ship. Ehresmann said the department is receiving guidance from the CDC and federal authorities about these passengers and when and under what conditions they could return to Minnesota.

jeremy.olson@startribune.com 612-673-7744

mara.klecker@startribune.com 612-673-4440