Genital shedding of herpes simplex virus-2 (HSV-2) is associated with increased genital shedding of HIV, according to a study presented to the 45th Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington DC. The study investigators suggest that providing the anti-HSV drug aciclovir to women with genital ulcerative disease may be a way of reducing the risk of HIV transmission.
It is known that the ulcers and subclinical disease caused by HSV-2 can increase an individual's risk of being infected with HIV. It is less clear, however, if infection with HSV-2 increases the risk of an HIV-positive individual transmitting HIV infection.
Investigators from Ghana, the Central African Republic, France and the UK conducted a randomised controlled trial to see if the use of aciclovir to treat genital ulcerative disease had an impact on the genital shedding of HIV.
A total of 274 women with genital ulcerative disease in Ghana and the Central African Republic were recruited to the trial. Blood samples and cervico-vaginal lavage were examined for the presence of HSV-1 and HSV-2, HIV viral load and HSV-2 genetic material.
Of the 163 women who were included in the study, 45% were infected with HIV and 76% with HSV-2. The investigators noted that women who tested positive for HSV-2 were significantly more likely to be infected with HIV (56%) than women who were HSV-2-negative (5%, p < 0.001).
In addition, the investigators noted that among the HSV-2-positive women, those infected with HIV were over twice as likely to shed HSV-2 than HIV-negative women (70% versus 29%, p < 0.001).
The investigators then restricted their analysis to the 53 women who were infected with both HIV and HSV-2. They observed that 76% of women who were shedding HSV-2 in their genitals were also shedding HIV. However, only 44% of women who were not shedding HSV-2 in their genitals had detectable HIV in this compartment. The difference was statistically significant (p = 0.02).
In further analysis, the investigators examined the 28 women who were shedding both viruses. They found that there was a correlation between the amounts of HIV and HSV-2 detected in the genital tract (p = 0.04). However, there was no difference in the HIV plasma viral loads between women who were shedding HSV-2 in their genitals and those who were not.
The investigators conclude, “these findings suggest that HSV-2 replication is associated with increased genital infectivity and support the hypothesis of aciclovir use in women with genital herpetic lesions as an effective strategy to reduce the infectivity of HIV."
Le Goff J et al. Increased genital shedding of HIV-1 RNA in HSV-2 and HIV-1 coinfected African women with genital ulcers. 45th Interscience Conference on Antimicrobial Agents and Chemotherapy, abstract H-1500, Washington DC, 2005.