Fears that antiretroviral therapy might lead healthier-feeling HIV-positive people to have more sex and potentially infect others may be unfounded, according to a new South African study, which recorded patients having significantly less sex as well as safer sex after starting treatment.
The study followed 2,332 HIV-positive patients enrolled in care who eventually started treatment at a large urban clinic in Soweto, Johannesburg's largest township, and a rural clinic in Mpumalanga province between 2003 and 2009. The participants were asked about their sexual behaviour before and after they started taking antiretroviral drugs (ARVs).
Both male and female patients were less likely to report being sexually active after they started ARVs, whether or not they had one main partner, a casual partner or both. They were also much less likely to report having unprotected sex and multiple partners.
"We actually weren't expecting to see these huge reductions," said one of the study's co-authors, Neil Martinson of the Perinatal HIV Research Unit (PHRU) at the University of Witwatersrand in Johannesburg. "I think we were expecting to see that people who regained their health would start engaging in more sexual activity rather than less."
The study, which was published in the AIDS journal, was not designed to find out why participants changed their sexual behaviour, but Martinson speculated that the experience of "staring death in the face" and then getting better on ARVs might make people less willing to infect others.
Counselling and safer sex messages during clinic visits may have also played an important role.
"When they come to clinics to start ARVs, they probably are bombarded with pamphlets and posters and other things that would encourage them to have safe sex," said Martinson.
Guy de Bruyn, also from PHRU and one of the co-authors, noted that the study was conducted in a research environment and might not reflect the experiences of HIV-positive patients accessing care through South Africa's under-resourced public health sector.
The authors nevertheless argue that the further expansion of ARV treatment programmes could have significant benefits for HIV prevention efforts in Africa.
"Double reason to start people on treatment"
The findings also have implications for a proposed prevention strategy known as "Universal Test and Treat", whereby population-wide HIV testing would be followed by immediate initiation on ARV treatment for everyone diagnosed positive. People on the drugs have a reduced viral load, making them less likely to transmit the virus.
However, there are concerns that the potential to infect others is not eradicated by ARV treatment and any benefit could be offset if individuals had more unprotected sex because they believed there was less risk (a phenomenon known as risk compensation or behavioural disinhibition).
"At least in our experience, [behavioural disinhibition] doesn't appear to be a major issue," said De Bruyn. "It shows that in people engaged in care over a long period, we don't see increases in risk behaviour."
The study is one of the first in the region to report on sexual risk among a large group of HIV-positive patients both before and after starting ARV treatment.
Martinson said the findings needed to be confirmed by a further study, preferably conducted in a public health setting and including patients who have been on treatment for at least five years. He added that there was also a need for a qualitative study that would conduct in-depth interviews with participants before and after starting treatment to ascertain the reasons for any behaviour change.
"If [the findings are] confirmed, there is double reason to start people on treatment, not just for their own health but to reduce sexual risk behaviour," said Martinson. - (IRIN/PlusNews, November 2010)