HIV-positive individuals who are taking HAART do not have more unprotected sex, according to a meta-analysis of studies looking at the impact of HAART on sexual risk -taking published in the July 14th edition of the Journal of the American Medical Association. The meta-analysis also revealed that HAART-treated patients with an undetectable viral load were no more likely to have unprotected sex than patients taking HAART who had detectable HIV. However, the study did find that both HIV-positive and HIV-negative individuals who believed that an undetectable viral load, or the use of HAART, reduced the risk of HIV transmission were significantly more likely to have unprotected sex.
Ever since HAART reduced illness and death in HIV-positive patients there have been concerns that this apparent reduction in the severity of HIV could lead to an increase in sexual risk taking. Recent increases in rates of sexually transmitted infections, particularly amongst gay men (who remain the group most at risk of HIV in countries where access to HAART is widespread), have been interpreted by some as evidence of a shift away from safer sexual practices.
Concern has also been expressed that the movement into the public domain of evidence showing that a low viral load reduces infectiousness could also lead to more sexual risk taking. HIV can still, however, be transmitted when an individual has an undetectable viral load.
Investigators conducted a meta-analysis of studies conducted since 1996 which have looked at the association between the use of and beliefs about HAART and sexual activity.
The investigators wished to answer three questions:
- Are HIV-positive individuals taking HAART more likely than HIV-positive patients not taking anti-HIV therapy to have more unprotected sex?
- Are HIV-positive individuals who are aware that they have an undetectable viral load more likely than HIV-positive patients who know that they have a detectable viral load to have unprotected sex?
- Are HIV-positive or HIV-negative individuals who believe that HAART or an undetectable viral load reduce the risks of HIV transmission more likely to have unprotected sex?
A total of 25 studies were included in the investigators' analysis. All were conducted between 1996 and 2001. Almost two-thirds were conducted in the US and the majority of studies included populations which were totally or mostly made up of gay men.
HAART and unprotected sex – no relationship found
A total of 16 studies looked at the relationship between receiving HAART and unprotected sex. In these studies a median of 59% of HIV-positive individuals were taking HAART. The median reported incidence of unprotected sex was 33% in the HAART group and 44% amongst patients not receiving HAART. The investigators coment, “the likelihood of engaging in unprotected sexual behaviour in the group of HIV-positive persons receiving HAART was not higher compared with the group not receiving HAART.”
Undetectable viral load and unprotected sex – no relationship
Twelve studies looked at the relationship between an individual having an undetectable viral load and sexual risk taking. All these studies classified patients into two groups: undetectable viral load or detectable viral load. A median of 37% of paitents had an undetectable viral load (ranging from below 50 copies/ml to below 500 copies/ml depending on the testing assay used). The prevalence of unprotected sex was a median of 39% was the patients with an undetectable viral load and a median 42% for individuals with a detectable viral load.
“The overall association between having an undetectable viral load and sexual risk behaviour was nonsignificant,” write the investigators as “the group of HIV-positive persons with an undetectable viral load was not more likely than the group with a detectable viral load to engage in unprotected sex.”
Beliefs about HAART and low viral load reducing transmission risk associated with more risk taking
The investigators did find that both HIV-positive and HIV-negative individuals who believed that HAART or an undetectable viral load made an individual with HIV less infectious were more likely to engage in unprotected sex.
Ten studies looked at this relationship. A consistent significant pattern emerged. The likelihood of unprotected sex was significantly higher in people who believed that HAART reduced the risk of HIV transmission. The median reported incidence of unprotected sex was 49% amongst individuals who believed HAART or a low viral load reduced the HIV transmission risk and a median of 38% for individuals who did not share this belief.
The association was significant in both US and non-US studies, in large and small studies, and in studies including populations of gay men and those that did not.
“This meta-analytic review of studies conducted since 1996 indicate that the prevalence of unprotected sexual intercourse was not significantly higher in the group of HIV-positive persons receiving HAART (vs not receiving HAART) or in the group of HIV-positive persons with undetectable (vs detectable) viral load.” However, “unprotected sex was…associated with people’s beliefs about HAART and viral load.”
The investigators speculate that individuals reporting that they believed HAART reduced the risk of HIV transmission may be engaging in “self-justifying thinking” to reduce the guilt after an unprotected sexual encounter. However, even if this were the case, the belief that a low viral load or HAART reduces the risk of HIV transmission “may still serve to sustain risky behaviour in the future.”
Limitations of the studies included in the meta-analysis are also noted, particularly the drawback that the overwhelming majority of studies did not look at the relationship between the duration of anti-HIV therapy and sexual risk taking, or the relationship between the health of individuals taking HAART and unprotected sex.
Prevention messages should emphasise that an undetectable viral load and the use of HAART does not eliminate the risk of HIV transmission, conclude the investigators.