The state Department of Health has stopped tracking how swine flu is being spread in Hawai'i since the virus is firmly ensconced and resources are limited.

"Early on in the outbreak, we were tracking down every case, but it's too widespread now," said Dr. Sarah Park, the state epidemiologist.

The department yesterday confirmed 205 new cases of the H1N1 virus, or novel influenza A, bringing the total of confirmed cases in Hawai'i to 503.

That number can be expected to increase in coming weeks and there's no telling how long the outbreak will last, Park said.

Instead of tracking the spread of the disease, the health department is focusing on monitoring the infection in target groups — including incoming travelers, those who suffer severe symptoms and people with underlying health problems.

The new cases reported yesterday were on Hawai'i, Maui, Kaua'i and O'ahu, but a more precise breakdown was not immediately available.

None of the people who have become ill here required hospitalization and there have been no deaths from the flu strain, which was first detected in Hawai'i last month.

"It's commonly circulating in the community and I wouldn't be surprised if we continue to see more and more cases. That's to be expected," Park said.

"It's been with us for some time and we don't know if it's going to fizzle out or calm down to the point where it becomes one of our regular flu virus strains."

Because this is a new virus strain, many people may have little or no immunity against it. The U.S. Centers for Disease Control and Prevention said most people who have become ill with the virus have recovered without requiring medical treatment. However, the agency said it anticipates "there will be more cases, more hospitalizations and more deaths associated with this pandemic in the coming days and weeks."

Health officials are concerned the virus could mix with the seasonal flu bugs — influenza A (H1 and H3) and influenza B — that are still active in Hawai'i and mutate into something more virulent in the fall and winter during flu season.

"We're looking for the kind of cases that would be of bigger interest, that would alert us that there would be a change in the virus or the severity of disease," Park said. "Right now pretty much everyone is recuperating at home, so the question in our mind is when will it start changing and when will we start to see more hospitalizations and, God forbid, our first deaths."

OTHER FLU STRAINS

With some of the other current flu strains in Hawai'i proving resistant to anti-viral medications such as Tamiflu, there is additional concern that the swine flu virus could develop similar characteristics, Park said.

The H1N1 flu has been detected in all 50 states and in more than 70 countries worldwide. As of June 13, nearly 21,500 cases and 87 deaths had been reported in the United States, according to the CDC.

Although the incidence of seasonal flu cases appears to be waning on the Mainland, Hawai'i is still seeing a large number of cases this summer, Park said. For now, at least, the seasonal flu is a much greater threat to Hawai'i residents, causing hundreds of hospitalizations and, with pneumonia, an average of 240 deaths annually.

"The majority of flu-positive specimens (tested by the Health Department) are still the seasonal flu. That's not the case on the Mainland," she said.

Park urged people to get vaccinated for the seasonal flu to help control its spread in Hawai'i. The vaccine for the 2009-10 flu season should be available in mid-September, she said.

A vaccine for the H1N1 flu is being developed but isn't expected to be widely available to the public.

"The seasonal flu is still a serious disease and it's still very important to control it. We don't want it co-circulating with the H1N1 virus and increasing the chances it will mix and change," she said.