CHAPEL HILL - Dr. Peter Leone hopes the day will soon come when getting an HIV test at the doctor's office is as routine as getting your blood pressure checked.

North Carolina, according to state epidemiologists, is on the national forefront of trying to knock down social barriers to HIV screening.

The U.S. Centers for Disease Control and Prevention came out with new screening recommendations two years ago advising all patients ages 13 to 64 to get tested as a routine part of medical care.

"Twenty-five to 30 percent of the people living with HIV don't know they're infected," said Leone, a UNC-Chapel Hill associate professor and medical director of the HIV/STD Prevention and Care Branch of the state Division of Public Health. "In North Carolina, about 40 percent of our [HIV-infected] folks, when they first come in, have AIDS."

On Friday, National HIV Testing Day, health care workers across the country urged people to know their HIV status.

By not having that information, people infected with the virus that causes AIDS can transmit it unknowingly to others. Not knowing also delays medical management of the virus.

"We believe that it's critical to identify these folks to improve their own health," Leone said. "We're 27 years into this epidemic, and we're getting people very late. They don't do as well with therapy when they're coming in late."

That's why infectious disease trackers are encouraged by the feedback they're getting from such clinics as Piedmont Health Services in Carrboro.

For the past year, the clinic has offered patients ages 13 to 64 free, rapid HIV testing. A drop of blood from a finger-prick is tested for the virus.

More than 70 percent of the patients have agreed to the test. After screening more than 4,000 people, six patients have tested positive for HIV.

In North Carolina, according to Bill Jones, an epidemiologist with the state division of public health, new HIV cases have risen to nearly 1,700 per year, up from the 1,500 reported five years ago.

The statisticians don't know whether more people are being infected or more cases are being recorded because of more routine screening in emergency rooms and doctor's offices across the state.

Before the CDC issued its new screening recommendations in 2006, health care workers had to ask sexual history questions that some people considered intrusive and then provide counseling before and after the tests.

The new screening procedures, which anyone can opt out of, have prompted fewer questions from teens and their parents.

"The resistance has been there more in the past in 'Why are you asking my kid about HIV testing?' " Leone said. "When parents are told this is something we offer to everyone, and this is national, we get very little resistance. We want to get to a point where screenings are as routine as blood-pressure tests. Your clinician doesn't say to you, 'You don't look like you have high-blood pressure, so let's don't check it today.' "