A male Oahu senior who returned to Hawaii last week from Washington state became the second resident to test positive for the new coronavirus, state officials said Sunday.

The man fell ill March 2 while traveling in Washington, flew home to Honolulu on Wednesday “and went straight to an urgent care facility because he wasn’t feeling well,” Gov. David Ige said at a 5 p.m. news conference.

Late Sunday night, the Hawaii Department of Health said the man flew back to Honolulu from Washington on Hawaiian Airlines Flight 21 on March 4.

After the man’s illness worsened Saturday, he was taken by ambulance to a hospital where he was tested for the virus.

“We confirmed the positive for COVID-19 this morning,” the governor said. The man is listed in serious condition.

The state is working with the federal Centers for Disease Control and Prevention to notify people who may have been in contact with the man.

“We definitely will be working through his specific travels and contacts he may have had,” Ige said. “We will be identifying who they are and reaching out to inform them that they have had contact with someone who is … presumptive positive for COVID-19.”

The man was being held in isolation Sunday at Kaiser Permanente’s Moanalua medical center. The urgent care facility he went to earlier was also operated by Kaiser.

The first Hawaii resident confirmed to have tested positive is under Kaiser care as well but is at home in self-isolation, said Laura Lott, Kaiser director of communications and public relations, in a news release Sunday.

State Health Director Bruce Anderson said despite the two positive cases, the state has yet to have a Hawaii resident test positive after having been infected here.

The first positive test, announced Friday, involved an individual who was a passenger on the Grand Princess cruise from San Francisco to Mexico from Feb. 11 to 21. The man traveled home to Honolulu with no symptoms but became ill while at home March 1, sought medical care and was tested Friday.

Anderson said state officials first learned about the second man Sunday morning and are still trying to gather details.

“We are, of course, progressively pursuing this and will be providing more information in the near future,” Anderson said.

Sarah Park, state epidemiologist, said that from what the state has learned so far, “we are confident there were few in terms of direct contacts in the state of Hawaii.”

She added, “This is a very ill individual and, from what we understand of the story, basically stayed in bed until the ambulance was called.”

The bad news regarding this second positive case is that he fell ill before he got on a plane and returned home, meaning the people on board with him might be at some risk. “From what we know, people are most infectious when they have symptoms,” Anderson said.

Park said the focus for both the state Health Department and CDC is to determine whom the patient came into contact with on the plane. She said CDC will likely try to speak with not just the passengers seated in the same row of the patient, but those up two rows in front and behind him.

Two Kaiser employees who came in contact with the second man will “stay at home for 14 days as a precaution,” Lott said.

Lott stressed that Kaiser Moanalua is safe to visit. “Kaiser Permanente has confronted highly infectious diseases for years,” Lott said. “Staff are following CDC protocols, and we’re confident we can safely treat patients who’ve been infected with this virus, with limited risk to other patients, members and employees.”

Park said she presumes the ambulance staff who transported the man were wearing proper protection and taking other precautions as they had been prescribed during training for exposure to patients with the virus.

To date, the Health Department said, 17 individuals have been tested in Hawaii at either the agency’s own lab or at Tripler Army Medical Center, which also has testing capability.

“At this point in time, all the people we believe have to be tested have been tested,” Ige said.

The state is working with the privately owned Diagnostic Laboratory Services and Clinical Laboratories of Hawaii to get them certified for testing as well, Ige said. “So we are definitely focused on increasing the number of … facilities that can conduct the test.”

The Health Department can conduct testing for up to 250 individuals weekly for COVID-19. “We expect the number of cases to increase and the number of individuals we will be testing to increase dramatically over the next weeks,” Anderson said.

This story has been updated to reflect that the Department of Health said late Sunday night that the man flew back to Honolulu from Washington on Hawaiian Airlines Flight 21 on March 4.