Recent infection with genital herpes ulcers substantially increases the chances of seroconverting for HIV, according to a recently issued policy brief from the South African Medical Research Council (MRC).
Herpes simplex virus II (HSV-2) is the most common cause of genital ulcers worldwide and it has long been recognised that by disruption of the epithelial barrier and general inflammation HSV-2 may increase the chances of infection with HIV.
The MRC policy paper is based upon the results of a study involving over 400 female sex workers at truck stops between Durban and Johannesburg. These women were screened for HIV. Only 198 were found to be HIV-negative and they were monitored monthly over three years. Of the women who seroconverted during the study, all but six became HSV-2 positive before they became HIV-positive, suggesting to the investigators that “immediately after infection with HSV-2, the risk of contracting HIV-1 increases significantly.”
However, investigators also found that women who were already HSV-2-positive at the start of the study had a lower risk of HIV seroconversion than those who were HSV-2-negative at the start of the study. The investigators speculate that the women already infected with HSV-2 were protected from reinfection with HSV-2, thus reducing the chance of acquiring HSV-2 ulcerative lesions which are a risk factor for HIV. The finding also lends support to the view that the two events of HSV-2 and HIV seroconversion are closely linked in time.
The South African MRC concludes that the study findings have “enormous public health implications in South Africa and the developing world where infection with HIV-1 and HSV-2 coexist” and make the following recommendations:
- There is an urgent need to recognise HSV-2 infection amongst populations at risk, especially amongst the young, and to provide treatment and counselling on condom use.
- Identification of HSV-2 infection in pregnancy may indirectly impact on mother-to-baby transmission of HIV-1.
- Priority should be given to the development of rapid tests for HSV-2.
- HIV and HSV-2 prevention efforts should be integrated.
- There is an urgent need to develop an HSV-2 vaccine which would curb both the spread of HSV-2 and HIV.
References
Ramjee G et al. Herpes simplex virus type II infection is a risk factor for HIV seroconversion. South African MRC policy brief 3, August 2002.