OMAHA, Neb. (AP) — Public health officials in Omaha have confirmed a second COVID-19 case whose origins can't be traced, Gov. Pete Ricketts said Wednesday, as Nebraska officials scrambled to increase the number of tests they can conduct each day.

In addition to the 46-year-old man infected through community spread, Douglas County health officials said three other travel-related cases have been confirmed. The department's director, Dr. Adi Pour, said those cases included a woman in her 60s, a man in his 60s and another man in his 40s. The three had visited other regions, including New York City, Denver and Europe.

Roughly 500 people have been tested so far for the coronavirus, Ricketts said at a news conference at the Capitol. The state now has 28 confirmed cases — 23 of them in the Omaha area.

Ricketts said he expects more tests will be available soon, and officials at the state's public health lab have figured out a way to test as many as 400 people per day, up from the current 100.

For most people, COVID-19 causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia.

A doctor at Bellevue Medical Center has tested positive, Nebraska Medicine spokesman Taylor Wilson said. Hospital employees and nine patients who had contact with the doctor have been notified, and the doctor, who is experiencing mild symptoms, is in isolation at home, Wilson said.

Ricketts said Nebraska residents have done a good job so far of complying with a 10-person limit in public settings such as bars, restaurants, day cares and concerts. Officials in Douglas County, which includes Omaha, are enforcing the rule with the threat of misdemeanor charges against people who violate it.

“Nebraskans are stepping up to that 10-person rule and complying with it,” Ricketts said.

Omaha-area officials meanwhile gave police and sheriff's deputies the authority to limit gatherings to try stop the virus' spread. The Douglas County Board of Health issued an order limiting gatherings to no more than 10 people. The order says a venue must be large enough for all people in any gathering to be at least 6 feet (1.8 meters) apart.

The local order followed calls Monday by state leaders to limit gatherings to 10 people.

The order is effective through April 30. It excludes courts, government operations, airports and public transportation, shopping venues, shelters and households with more than 10 people. Child care facilities are limited to the 10-person order.

Pour said she believes any delay in implementing the measure “would significantly jeopardize the ability to prevent or limit the transmission of a communicable disease and pose unacceptable risks.”

The order comes on the heels of similar measures being imposed across the U.S. to limit exposure to the coronavirus, including limits on crowd size, closing schools and businesses and postponing upcoming primary elections. In the U.S., the death toll from the virus has far surpassed 100, and officials have urged older Americans and those with health problems to stay home.

Day care providers urged parents to keep their children at home if possible, so the children of health care workers, first responders and grocery store employees can be made a priority.

“It is essential that those people can continue to work so they can provide safety for our communities,” said Theresa Thibodeau, an Omaha-area day care owner and former state senator.

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Associated Press writer Grant Schulte in Lincoln contributed to this report.

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