When researchers adjust their definition of “safe sex” to account for the preventive effects of HIV-positive people having an undetectable viral load and HIV-negative individuals being on pre-exposure prophylaxis (PrEP), the proportion of men who have sex with men (MSM) who engage in sex that puts them at high risk for HIV transmission falls dramatically, aidsmap reports.
In other words, the old definition of safe sex may vastly overestimate the risk of transmission among gay and bisexual men.
Keith Horvath, PhD, of the University of Minnesota, and colleagues analyzed data on 401 HIV-positive MSM in New York, 281 of whom reported anal sex during the past three months and were the focus of the analysis. The men were participants in a study that sought to increase adherence to antiretroviral treatment.
The researchers published their findings in the Archives of Sexual Behavior.
The men had an average age of 38 years old and were diagnosed with HIV an average of 12 years prior. The majority were Black, and one in three had a college degree. They reported an average of nine sexual partners during the previous three months. Half reported using stimulant drugs, such as crystal meth or cocaine.
Traditionally, “risky sex” on the part of people with HIV is defined as sex without a condom (aka “barebacking”) with a partner who does not have the virus or is of an unknown HIV status. Forty-two percent of the men in the study reported such sex within the previous three months.
The researchers then narrowed the definition of risky sex, defining it as condomless sex between an HIV-positive man with a viral load over 200 and a partner who is HIV-negative or does not know his HIV status. Just 6% of the men in the study reported such sex during the previous three months.
Studies have shown that people who have a viral load below 200, or who otherwise have an undetectable viral load (typically below 50, depending on the test), do not transmit the virus through sex.
The new study’s authors also tightened the definition of risky sex based on whether the men’s partners used PrEP, which reduces the risk of sexual acquisition of HIV by more than 99%. Twenty-five percent of the men reported condomless anal sex with an HIV-negative partner or a partner with an unknown HIV status who was not on PrEP.
Just 2% of the men reported both having a viral load above 200 and engaging in condomless sex with an HIV-negative or unknown-HIV-status man who was not on PrEP.
“These findings have implications for whom to reach for intervention efforts, the difficulty in meeting recruitment goals and the types of interventions that should be used,” the study authors concluded.
To read the aidsmap article, click here.
To read the study, click here.