The state Department of Health on Thursday announced that the first confirmed case of the omicron variant has been detected in Hawaii.

An Oahu resident — an adult under age 65 — tested positive for the variant with mild to moderate symptoms and was previously infected with COVID-19 over a year ago but was never vaccinated, according to state health officials.

The individual had no recent history of travel, which indicates community spread — meaning others here are likely infected with the variant.

“This isn’t reason for panic, but it is reason for concern,” said state Health Director Dr. Elizabeth Char in a news release. “It’s a reminder the pandemic is ongoing. We need to protect ourselves by getting vaccinated, wearing masks, distancing as best we can and avoiding large crowds.”

The news came a day after the U.S. announced its first known case of the new variant in a person from California who had recently traveled to South Africa. On Thursday omicron was also confirmed in a man who recently attended an anime convention in New York City.

The World Health Organization has classified omicron, or B.1.1.529, first detected in South Africa, as a variant of concern and warned that it poses a very high global risk.

While much remains unknown about omicron and whether it causes more severe disease, the number of COVID-19 infections in South Africa has surged in recent weeks, along with questions about the variant’s ability to break through vaccines and natural immunity.

DOH said Diagnostic Laboratory Services on Monday identified a test specimen with a molecular clue indicating the possibility of the omicron variant and quickly forwarded it to the state. With expedited whole genome sequencing, the State Laboratories Division confirmed Thursday it was the omicron variant.

Contact tracing is underway, according to state Epidemiologist Dr. Sarah Kemble, who had no further details on how many contacts were being tested or what places the infected individual had been to.

Kemble said the resident is in isolation and that symptoms so far include classic COVID-19 signs such as headache, body aches and coughing.

Given there is no link to travel for the person, she said there are likely more undetected cases in Hawaii.

There are still many unknowns about the omicron variant, she said, but the arrival of omicron is “definitely cause for caution.”

“While the variant is something we will definitely want to watch and track, we still anticipate vaccination is going to be one of the best ways to prevent transmission, whether it’s getting the first dose or getting a booster against COVID-19,” Kemble said. “It’s still really important to wear a mask and practice mitigation strategies, like maintaining a distance as much as you can and staying home when sick.”

On Thursday, DOH reported 126 new infections statewide, bringing the state’s total since the start of the pandemic to 87,898 cases. Another death was reported on Oahu, bringing the state’s COVID-19 death toll to 1,027.

The seven-day average of new daily cases statewide was 83, while the average positivity rate was 1.4%.

As of Thursday, 71.5% of the state’s population had completed COVID-19 vaccinations, according to DOH. More than 241,000 booster shots have been administered, representing roughly 17% of the state’s population.

Hilton Raethel, president and CEO of the Healthcare Association of Hawaii, said that as of Thursday, 38 COVID-19 patients were hospitalized statewide, including eight in intensive care units.

But hospitals are very full with about 2,300 non-COVID-19 patients, he said, at a level pretty close to the peak of the delta variant surge earlier this year.

“What we are seeing is a lot of patients who are sick or have fairly severe illness because of care that was delayed or deferred, and that is starting to catch up with a lot of people,” he said.

Raethel said the discovery of omicron in the isles was inevitable given how highly transmissible the variant appears to be. But at this point it does not appear to have resulted in significant hospitalizations, severe illness or death. That could change, however, he said.

Contingency plans are in place if Hawaii’s COVID-19 numbers resurge, including going back to the Federal Emergency Management Agency for traveling health personnel to supplement the local health care workforce.

“At this point in time we believe we’re in a pretty good place when it comes to being able to manage COVID in our hospitals,” Raethel said.

In response to news of the omicron variant on Oahu, Honolulu Mayor Rick Blangiardi on Thursday tweeted, “While it is concerning, it is not necessarily surprising based on our prior briefings with health officials. We will continue to work with the experts to learn more about this variant.”

Blangiardi’s relaxation of COVID-19 restrictions, which eliminated capacity limits, just went into effect Wednesday.

Tim Brown, an infectious disease modeler at the East-West Center in Manoa, said omicron’s arrival calls for immediate action from public officials.

“All the lifting of restrictions have got to go,” he said. “They need to be removed as of yesterday. We cannot have people gathering in bulk this weekend. It’s the height of insanity to let people gather in large groups now that we know omicron is here.”

In addition, he said Hawaii needs to implement coronavirus testing for out-of-state travelers in addition to proof of COVID-19 vaccination, ideally within 24 hours of boarding a plane and three to five days after arrival to the state.

Brown said he is particularly concerned the infected Oahu resident had no travel history, meaning omicron has possibly been circulating locally for a couple of weeks already.

Hawaii also needs to ramp up its testing ability for COVID-19, he said, adding he hopes health officials are “radically contact-tracing right now.”

Some of the state’s medical doctors also have been calling for the state to revise its Safe Travels program to include testing as well as proof of vaccination for out-of-state travelers.

Dr. Jonathan Dworkin, an infectious disease specialist on Hawaii island, and Dr. Darragh O’Carroll, a Honolulu emergency physician, wrote in an Island Voices column published Thursday in the Honolulu Star-Advertiser that there is good reason to worry about omicron.

Cases of COVID-19 are increasing faster in South Africa than during the delta surge, they noted, and “it would be foolish to assume it will cause a much milder disease.”

Hawaii should require daily rapid testing five to seven days after travel in lieu of quarantine to lower the impact of the coming wave.

“High volume travel will create an opportunity for the virus,” they wrote. “Failure to use the Pacific Ocean, a vast strategic advantage, would be a blunder.”

The omicron variant has been detected in at least 23 countries and four other states: California, Minnesota, New York and Colorado.