An uptick in COVID-19 cases has begun, indicating the possibility of an upcoming wave this summer in Hawaii.

The Hawaii Department of Health has tracked consecutive increases in COVID-19 positivity rates over the past five weeks as new variants take hold in the islands.

Health officials on Wednesday reported an average positivity rate of 10.5%, up from 8.5% the previous week. On May 1, the average positivity rate was at 4.3%. The seven-day average reported Wednesday reached 100 per day, double what it was mid-May.

The uptick is likely driven by the arrival of new “FLiRT” subvariants, which are now dominant in the U.S.

DOH in its latest variant report noted that the “FLiRT” variants, including KP.1.1, KP.2 and KP.3 have been present in the state since mid-April. The FLiRT variants — named after the technical names for their mutations — are descendants of JN.1, which was dominant in the U.S. earlier this year.

The mutations potentially make the variants more immune-evasive by improving their binding ability to cells, and could possibly drive a new wave of COVID cases this summer, according to Johns Hopkins Bloomberg School of Public Health.

State health officials, meanwhile, are warning that COVID activity is on the rise, based on DOH’s new respiratory disease activity dashboard.

The dashboard, developed by the department’s Disease Outbreak Control Division, provides a snapshot of current respiratory disease activity statewide, including COVID, flu and respiratory syncytial virus.

Currently, COVID is at the yellow, or medium activity level, meaning the virus is circulating at higher levels than would be expected based on historic trends.

Flu and RSV remain at green, or low activity levels, and overall acute respiratory disease is at the medium level.

“The new Respiratory Disease dashboard provides, in one place, a summary of what is happening with several major respiratory viruses that contribute to respiratory disease in Hawaii,” state Epidemiologist Sarah Kemble said in a news release. “This helps people make informed decisions about their health.

“This week, the dashboard shows that COVID-19 test positivity is higher than expected and climbing,” she continued, “and that (emergency department) visits and hospital admissions for COVID-19 are also going up. Based on this information, I would recommend checking whether you’ve had the 2023-24 COVID-19 vaccine, and if not, or if you’re eligible for a repeat dose, go get it today.”

In February, the Centers for Disease Control and Prevention had recommended an additional dose of current COVID vaccines for Americans ages 65 and older who had received one in the fall. The formula for the upcoming fall COVID vaccine has yet to be determined.

State hospitalizations have also been on the rise, with 55 COVID patients reported May 22, up from 27 two weeks ago.

Although not federally required to do so, DOH said it will continue to post COVID hospitalization information online because it is a key indicator of the burden of the coronavirus in the community.

DOH and the Healthcare Association of Hawaii launched the Hawaii Hospital Capacity System, which provides near real-time information on the number of beds filled and admission trends.

Based on CDC’s wastewater data, current levels of the coronavirus in Hawaii are very high, much higher than the U.S. average.

Tim Brown, infectious disease expert from the East-West Center in Manoa, notes there have been rapid rises in COVID in Australia, New Zealand and Singapore, as well, due to the new variants.

Brown said he expected metrics to continue rising for another few weeks, but hoped it would not be above January levels.

“The good news is no indications of any increase in severity,” he said.

People should still take precautions, he said, particularly if immuno-compromised or at high risk.

“While COVID is less of a threat now,” said Brown in an email, “it is still a systemic illness that leaves a lot of post-infection damage: increased heart attacks and strokes, lingering illness, autoimmunity, ongoing inflammation, etc. — much of which we may not recognize fully for many years.”

On Wednesday, DOH reported no COVID-related deaths, keeping the COVID death toll in Hawaii at 2,174.