The number of new AIDS cases in Hawai'i has remained relatively stable over the past six years, but state health department official who deals with sexually transmitted diseases said he's disappointed that the count hasn't dropped.

"We would think by now we would be seeing fewer cases since treatment has been available for some time," said Peter Whiticar, chief of the department's STD/AIDS Prevention Branch.

That means some AIDS patients have never gotten treatment or aren't conscientiously following a treatment regimen, Whiticar said, or that treatment has not been successful in some cases.

According to the health department, 109 new AIDS cases were reported in 2005. At the end of the year, 1,305 people with AIDS were known to be living in Hawai'i.

Whiticar said the newly reported AIDS cases are people who have had the human immunodeficiency virus for years and developed significantly weakened immune systems or any of an assortment of ailments symptomatic of AIDS.

Since 1983, when the disease first became widely recognized, 2,847 AIDS cases have been reported in the Islands, with 1,542 known dead from the disease.

Reliable data on the number of Hawai'i residents infected with HIV, the virus that causes AIDS, is not available.

Whiticar said the Department of Health's HIV reporting system uses codes, not names, to identify patients. The system has not been able to provide accurate and complete data because of the potential for duplicate reporting and other problems, he said.

In accordance with recommendations from the Centers for Disease Control and Prevention, the state is in the process of changing to a reporting system based on patient names.

In the meantime, Hawai'i health officials estimate the number of HIV-infected residents at 2,300 to 3,200, including those with AIDS.

Even with a named-based reporting system, Whiticar points out that getting clear data on HIV infections will remain elusive, because only those who test positive for the virus are counted. The number of people who are HIV-infected and don't know it will remain a mystery.

Getting accurate data on AIDS cases also is a challenge, because some of the "new" cases may be patients who were diagnosed years earlier but are only now being reported.

Of the 109 cases in 2005, 58 were reported on O'ahu, 18 in Maui County, 12 on the Big Island, and 21 on Kaua'i. Eighty-nine percent are male.

When broken into age groups, the largest proportion falls within the 40- to 49-year-old category. One of the new cases is a teenager.

Fifty-eight percent are Caucasian, with Asians accounting for 12 percent and Hawaiians/Pacific Islanders for 8 percent.

Male-to-male sex remains the most common risk factor for AIDS, and was attributed to 62 percent of the new cases. Lesser factors were heterosexual contact and injection drug use.

The distribution of AIDS patients in Hawai'i closely resembles a breakdown of the general population, with 72 percent of cases reported since 1983 occurring on O'ahu, where almost three-fourths of the state's residents live. Thirteen percent of the cases were reported on the Big Island, 10 percent on Maui, and 4 percent on Kaua'i.

Whiticar said this creates a challenge for public health officials because elsewhere in the country, HIV/AIDS cases are concentrated in urban areas where health and prevention services can be more easily targeted.

In Hawai'i, the need for HIV/AIDS programs is more widespread, including rural areas where it's tough enough for residents to access healthcare because of poverty, lack of transportation and other issues.

Before 1995, contracting the HIV virus was considered a likely death sentence. But advances in medication and treatment mean many HIV-infected people today may never develop AIDS.

Public health officials fear recent increases in other sexually transmitted diseases such as gonorrhea and syphilis could open the door to more HIV infections.

With effective treatments and news of HIV/AIDS largely focused on problems in the Third World, some people in this country have become complacent about avoiding unsafe sexual behavior, Whiticar said.

If these people don't get tested or don't develop symptoms until later, it could be years before a corresponding increase in HIV/AIDS cases is noted, he said.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.