A study of nationally representative survey data found that 11% of men who have sex with men (MSM) who are diagnosed with HIV reported having recent sexual encounters with men that could pose a risk of transmission of the virus.

The Centers for Disease Control and Prevention (CDC) estimates that about four out of five new HIV transmissions in the United States are attributable to people who are diagnosed with HIV but not in medical care for the virus or people who have not yet been diagnosed. The CDC further estimates that about 70% of new HIV acquisitions in the United States are among MSM.

As described in the Journal of Acquired Immune Deficiency Syndromes, Sharoda Dasgupta, PhD, MPH, of the CDC, and her colleagues analyzed 2015 to 2019 survey data from the Medical Monitoring Project, an annual study that reports representative estimates about HIV-positive adults in the United States.

The study included data on the sexual behaviors of 4,923 HIV-positive MSM, which the men reported through interviews, as well as viral load test results from their medical records. The participants reported on their last five sexual partnerships during the previous 12 months, including the HIV status of their partners and whether any HIV-negative partners were taking pre-exposure prophylaxis (PrEP).

The study analyzed 13,024 sexual pairings reported by these men, including 7,768 such partnerships in which their sex partners were HIV negative or of an unknown HIV status.

The study defined high-risk sex as the HIV-positive man: 1) not having a sustained undetectable viral load; 2) having condomless sex with a partner who was HIV negative or was of an unknown HIV status; and 3) having sex with such a partner who was not known to be taking PrEP. In other words, the sexual encounter was not protected by viral suppression, a condom nor PrEP.

Sixty-six percent of the respondents reported condomless sex. Eleven percent reported high-risk sex. There was no significant difference in the rate of high-risk sex based on race. African Americans were more likely to have a detectable viral load but less likely to report condomless sex compared with whites.

The study authors analyzed the individual pairings in which the HIV-positive men reported sex with a partner who was HIV negative or of unknown HIV status. After controlling for age, they found that compared with when the HIV-positive partner was white, there was a 44% lower likelihood that the sex was high risk when he was Black and a 44% lower likelihood when he was Latino.

“In the context of ending the HIV epidemic, behavioral and clinical surveillance data can help monitor HIV transmission risk and target prevention efforts to reduce transmission among populations at disproportionate risk,” the study authors concluded.


To read the study abstract, click here.