HIV Detected in Semen of Those on HIV Meds
By Robert Folan-Johnson
Distributed By Healthy Living News
Several new studies show that some on antiviral therapy may have enough HIV in their semen to transmit the virus to others. The studies also suggest that the highly promising approach of reducing HIV transmission by putting people with HIV on antivirals may have some limitations.
That may be even more the case for men who frequently have sex with other men (MSM).
Many HIV-infected MSM continue to engage in unsafe sex exposing themselves to sexually transmitted infections (STIs). However, these promote HIV replication and transmission. With that risk in mind researchers sought to determine how many men on HIV antiviral treatment, or HAART, have HIV in their semen.
The study, which appears in the journal AIDS, recruited 101 men from The Fenway Community Health Center in Boston. All had been on HAART for over three months with 80% of them on treatment for over a year. The researchers measured levels of HIV in both the blood and semen. They also checked for other infections that might be increasing HIV levels.
Almost two out of ten men in the study had detectable HIV in the blood despite being on HAART. However, three out of ten men in the study also had HIV in their semen. Those levels were high enough to potentially spread HIV through sexual contact.
"It has been shown before that HIV levels in peripheral blood are an important predictor of seminal HIV," explained lead author Joseph Politch, PhD, professor in obstetrics and gynecology at Boston University.
In addition to HIV in the blood, other factors were strongly associated with having detectable HIV in the semen according to the study. These were having unprotected anal sex as a "top", (unknowingly) having a sexually transmitted infection, or having high levels of the inflammatory immune marker cytokine TNF-?.
"Our study provides evidence that genital infections and inflammation are common in HIV-infected MSM that engage in unprotected intercourse, and that these factors can promote HIV in the genital tract of men on suppressive HAART, even when HIV is not detectable in blood," said Dr. Politch.
Another concern is that actively reproducing seminal HIV in men on HAART may lead to the development and transfer of drug resistant virus.
A recent French study shows that 7% of heterosexual men on antivirals also had measurable levels of HIV in their semen. Blood viral load levels were detected in 17% of the 628 study participants. This study was also published in the journal AIDS.
Other studies have confirmed that men who have an undetectable blood viral load are still capable of transmitting HIV, although that risk may be dependent on the route or type of sexual transmission. Dr. Politch thinks some men who have sex with men believe the risk of HIV transmission is low based on incorrect assumptions that HAART eliminates HIV from semen. The new studies should be a concern for these men because HIV is more transmissible through anal sex that it is through heterosexual sex.
The studies also reveal that treatment as prevention - stopping HIV transmission through antiviral therapy - may have its limitations. That approach, based on a landmark 2011 study of heterosexual couples showed antivirals reduce HIV transmission from a positive partner to a negative one by 96%. The Fenway study suggests that level of protection may not hold true for risk taking MSM, especially if HIV transmission is being unknowingly enhanced by an STI such as herpes or syphilis.
"Until more information on transmission risk in MSM is available it would be prudent for sexually active HIV-infected MSM to use condoms and other risk-reduction strategies throughout all stages of HIV disease, regardless of HIV treatment status, and to promote the aggressive diagnosis and treatment of STIs," cautioned Dr. Politch.
In the Fenway study, stronger antiviral regimens or treatment duration did not appear to have an effect on whether the men had a detectable seminal viral load. The hope is that new HIV therapies may be more effective in lowering viral load throughout the body and reduce the risk of transmission.
Kenneth Mayer, MD, of Fenway Health and a co-investigator the study added: "We would like to extend this research to study the effects of newer HAART regimens, since newer agents may have different effects on HIV suppression in different compartments in the body, which may have implications for HIV prevention."