WEDNESDAY, Dec. 5, 2007 (HealthDay News) -- Most men newly infected with HIV (the virus that causes AIDS) choose to have unprotected sex only with other HIV-infected partners, say U.S. researchers who analyzed data from six clinics in San Francisco, New York City, Los Angeles, New Haven, San Diego and Providence, R.I.
The study included 27 men with acute HIV infection. This refers to the one-month period immediately following HIV infection, when a person tends to have the highest levels of HIV circulating in their blood. This makes it much more likely they'll infect a partner during unprotected sex.
More than 90 percent of the patients in the study were men who have sex with men.
"While the findings showed condom use was up and the number of partners was down, the most startling effect was seen in men choosing to have unprotected intercourse almost exclusively with other HIV-infected individuals. This reflects a systematic shift by men, most of whom are gay, following HIV infection to behaviors that protect their sex partners," lead author Wayne Steward, assistant professor of medicine at the University of California, San Francisco's Center for AIDS Prevention Studies, said in a prepared statement.
Prior to HIV infection, the men in the study had unprotected sex with HIV-negative or HIV-unknown partners almost 75 percent of the time. After learning they were infected with HIV, there was a major change in their behavior. They started having unprotected sex with other HIV-positive partners 97 percent of the time.
The finding has implication for HIV prevention efforts, Steward said. "If all you are doing is counting condom usage, you are missing a powerful risk-reduction strategy that is actually taking place," he said. "In addition, this study highlights the importance of identifying acute or recent HIV infections, so that this partner selection strategy can be implemented at the critical juncture when individuals are most infectious and when our data show they engage in behaviors reflecting strong motivations to avoid infecting someone else."
The study was to be presented Wednesday at the U.S. Centers for Disease Control and Prevention National HIV Prevention Conference in Atlanta. It comes on the heels of new data from two U.S. studies, released at the same meeting Monday, that found that about a third of HIV-infected gay or bisexual men report having recently engaged in unsafe sex.
However, in many cases, men were selecting other HIV-positive partners when engaging in unsafe sex, a practice called "serosorting," the studies' researchers said.
The American Academy of Family Physicians has more about reducing HIV/AIDS risk.