SATURDAY, July 19, 2014 (HealthDay News) -- A new report offers good and bad news about the AIDS epidemic in the United States: The annual diagnosis rate of HIV, the virus that causes the disease, has dropped by one-third in the general population but has climbed among young gay and bisexual males.
Significantly fewer heterosexuals, drug users and women were diagnosed each year with HIV, according to the report from the U.S. Centers for Disease Control and Prevention. However, the annual diagnosis rate more than doubled for young gay and bisexual males.
The push for safer sex may be falling on deaf ears in a generation too young to have seen the ravages of AIDS, said report co-author Amy Lansky, deputy director for surveillance, epidemiology and laboratory sciences at the CDC's Division of HIV/AIDS Prevention.
"It's been more than 30 years since the first cases were reported," she said. "It's harder to maintain that sense of urgency."
The report only looked at people diagnosed with HIV, and health officials think many more are infected with the virus but don't know it. The statistics also don't say anything about when these people were infected, making it hard to pinpoint trends in efforts to prevent transmission of the virus.
Still, "we're making significant progress and seeing declines overall," said Lansky. However, she added, the rising numbers of diagnoses among young men who have sex with other men are "a considerable problem."
The AIDS epidemic began more than 30 years ago. While the last two decades have brought great advances in drugs that prevent AIDS from developing in HIV-positive people, an estimated 1.1 million people are still living with HIV in the United States, Lansky said. Officials believe about 16 percent of those people -- or about 176,000 -- don't know they're infected, she said.
In the new report, published in the July 23/30 issue of the Journal of the American Medical Association, researchers examined HIV diagnoses in the United States from 2002 to 2011 in people aged 13 and older.
Although almost 500,000 people were diagnosed with HIV during that time, the annual rate of diagnoses fell from 24 out of every 100,000 people to 16 -- a decline of 33 percent.
Many groups experienced significant declines in infection.
Among women, diagnosis rates dropped by about half, and among men by more than one-quarter. For blacks and Hispanics, the rates of diagnosis declined 37 percent and 41 percent, respectively.
The report estimates that HIV infections due to injection drug use fell by roughly 70 percent and from heterosexual contact by more than one-third for men and women.
Distribution of sterile needles, increased HIV testing and drug-treatment programs could explain some of the downward trend, Lansky said.
But the diagnosis rate jumped among males aged 13 to 24, suggesting that many gay and bisexual young men aren't using condoms during sex. The number of newly diagnosed cases in that age group rose from about 3,000 to about 7,000, Lansky said.
"The increases tell us where we need to keep putting our efforts," Lansky said. "To build on the progress that we've made, we're really starting to focus on those who are in greatest need."
Dr. David Margolis, an AIDS specialist at the University of North Carolina at Chapel Hill, said one way to do that is to promote use of HIV drugs by people who are at risk but not infected. "Pre-exposure" treatment is controversial, however, because some experts fear it might encourage users to have more unprotected sex.
"The use of antivirals to prevent HIV infection is fraught with many challenges," Margolis said, "but if there is a more than doubling of new infections in one demographic, perhaps something needs to be done."
The University of California, San Francisco has more about diagnosing HIV.