With immediate treatment of HIV, semen viral load drops rapidly, reports small study

Starting antiretroviral treatment immediately upon HIV diagnosis not only helps preserve a person’s health, but also quickly reduces semen viral load to levels where the virus is unlikely to be transmitted, according to the results of a small study conducted in Peru.

About This Study

“Viral load dynamics in plasma and semen when ART is initiated during early HIV-1 infection“ was published online as a brief report on Nov. 24, 2023, in The Journal of Infectious Diseases. The lead authors are Trupti Gilada, M.D., M.B.B.S., of the Unison Medicare & Research Center in Mumbai, India, and Angela K. Ulrich, Ph.D., M.P.H., of the Center for Infectious Disease Research and Policy, and the Division of Environmental Health Science, both at the University of Minnesota in Minneapolis. Study drugs were donated by their manufacturers, Gilead Sciences and Merck Sharp & Dohme Corp., respectively.

Key Research Findings

Researchers assessed HIV viral loads in semen and plasma during primary HIV infection–29 men who started antiretroviral treatment immediately and 37 men who delayed treatment–in Lima, Peru, between 2013 and 2017. In this prospective trial, participants were initially randomized to the two arms, but those in the delayed arm were offered treatment if they met local treatment criteria prior to 24 weeks and were then censored on treatment start, with 66 individuals completing the study.

At baseline, semen viral load was >1,000 copies/mL in 83% of all participants, indicating potential onward transmission of the virus. In 35% of untreated participants, that level remained through the end of their study participation. In treated participants, semen viral load declined rapidly, with 25 participants achieving < 1,000 copies/mL by week 12.

Plasma viral load was slightly higher in the immediate vs. the deferred treatment arm at baseline. By week 24, 27 participants had reduced semen viral load to ≤160 copies/mL–defined as viral suppression–while continuing to have plasma viral loads >40 copies/mL, the viral suppression threshold. Over the course of the study, plasma viral load measurements were higher in the deferred vs. the immediate treatment arm.

By week 12, seven participants in the immediate and 23 in the deferred treatment arm were diagnosed with a sexually transmitted infection. Semen viral load remained suppressed in all but one participant in the immediate arm but rose >1,000 copies/mL in 13 participants in the deferred arm.

Discussion Highlights and Implications for Practice

Study limitations reported by the authors included the small sample size and self-reported behavioral data.

The researchers said their findings suggest there is a high semen viral load during the early weeks of a primary HIV infection and that plasma viral load, the more commonly available measure, is a good but conservative predictor of semen viral load during this same time period. In addition, they reported that almost all participants treated with antiretroviral therapy maintained suppressed semen viral loads after a diagnosis of another sexually transmitted infection while many in the deferred treatment group did not.

Results show the importance of HIV testing, rapid linkage to care on diagnosis, and an immediate treatment start for reducing onward HIV transmissions, they concluded.

By Barbara Jungwirth