Dr. Shay Keating still advises caution about a controversial Swiss report on HIV/AIDS
In 2008, a statement on behalf of the Swiss Federal Commission for HIV/AIDSwas published in the Bulletin of Swiss Medicine. The statement read, ‘after review of the medical literature and extensive discussion […] an HIV infected person on antiretroviral therapy with completely suppressed viremia (effective antiretroviral therapy, ART) is not sexually infectious, i.e. cannot transmit HIV through sexual contact.
This statement, the Swiss group added, was only valid as long as the person was adherent to ART, was virally suppressed (a viral load less than 40 copies per ml of blood) for at least six months, and there were no other sexually transmitted infections. The World Health Organisation promptly responded, reaffirming their recommendation that all HIV infected individuals should use condoms during sex to limit the spread of the disease.
This provocative Swiss report is based on several well reviewed pieces of research including one funded by the National Institute of Health in Uganda. This study showed that with serodiscordant couples, where one partner was negative and one positive but virally suppressed, the chance of infection was low. Similarly, the HIV Prevention Trials Network study HPTN 052 demonstrated in 2011 that ART was a powerful tool in reducing the likelihood of HIV transmission by 96%. The risk of HIV transmission when virally suppressed is very low.
Is there any such thing as zero risk of HIV transmission? Recently, it has been argued that viral suppression in the blood is not a guarantee against HIV transmission. A viral load result is just as good as the last sample taken as many on ARTs are tested at 3 or 4 monthly intervals. It is well known that viral load blips occur where persons who had been virally suppressed have temporary detectable viral loads and are theoretically more infectious.
There is no way of knowing in between clinic reviews, when one is about to have sex, what one’s viral load is, undetectable or with an upward blip. In addition, in a study published this year, it was noted that when paired blood and semen samples of HIV infected men were tested for HIV viral load, 6.6% of the men had detectable virus in the semen when not detected in the blood. Shedding of the virus in the genital tract is not uncommon and appears to be unpredictable. This shedding is also increased by sexually transmitted infections, inflammation of the urethra and genital inflammation.
Finally, condom use limits the spread of many sexually transmitted infections (STIs), not just HIV. Controlling STIs has been shown to limit the spread of HIV. If we advocate that ARTs limit HIV transmission and suggest that condoms are not needed anymore, are we not risking the spread of asymptomatic STIs which would increase the risk of HIV infection in serodiscordant couples? I believe that to continue recommending safer sex practices for all HIV infected couples is appropriate and advisable.
Dr. Keating is an Associate Specialist in Genitourinary Medicine for St. James’ Hospital, Dublin and has his own practice at Harold’s Cross Surgery.