Serodiscordant couples should still be careful
I included this story in a News Notes post a couple days ago, but I found a more detailed article from the Kaiser Network, and thought I’d add a little.
The Swiss AIDS Commission made a statement in January “that said HIV-positive people in discordant relationships who adhere to their treatment regimens, have suppressed viral loads and do not have other sexually transmitted infections likely would not transmit the virus through sexual contact.”
A group of Australian researchers, however, calculated that while the risk of transmission under those conditions is small for any individual instance of unprotected sexual contact, the risks added up over time. According to the Kaiser article:
The researchers found there would be an additional 215 female-to-male HIV transmissions, 425 male-to-female transmissions and 3,524 male-to-male transmissions if discordant couples became more complacent about condom use (Reuters, 7/25). The study found that an HIV-negative man would have a 0.22% annual risk of contracting HIV from an HIV-positive female partner, while an HIV-negative woman would have a 0.43% annual risk of contracting HIV from an HIV-positive male partner. HIV-negative men who have sex with men would have an annual 4.3% risk of contracting HIV from an HIV-positive partner, the study found (AFP/Google.com, 7/24). According to the researchers, the findings represent “an increase in incidence of four times compared with incidence under current rates of condom use” (Reuters, 7/25).
The study was conducted in response to a Swiss AIDS Commission statement released earlier this year that said HIV-positive people in discordant relationships who adhere to their treatment regimens, have suppressed viral loads and do not have other sexually transmitted infections likely would not transmit the virus through sexual contact. “If the Swiss commission’s conclusions were adopted at a community level and resulted in reduced condom use, it would be likely to lead to substantial increases in infection,” Wilson said.