Does having herpes (HSV-2) increase your chances of being infected with HIV?

MRC

Yes! It is most definitely a risk factor that has serious public health implications, is the finding of a Policy Brief released by the HIV Prevention Research Unit of the Medical Research Council (MRC).

Herpes simplex virus type II (HSV-2) is the most common cause of genital ulcer disease worldwide. By damaging the epithelial barrier and causing inflammation, it may increase the risk of HIV-1 transmission.

"It was therefore important for us to further investigate the relationship between HIV-1 and HSV-2 and the associated risk factors. We measured baseline HIV-1 and HSV-2 among a group of female sex workers participating in a vaginal microbicide clinical trial and, investigated the risk factors associated with HIV-1 and HSV-2 . We studied the effect that infection with HSV-2 had on the eventual incidence of HIV-1 among women who started the trial being HIV-negative. In other words, the relationship between the incidence of HSV-2 and HIV," says Dr Gita Ramjee, Principal Investigator of this study.

According to the Policy Brief, 416 women were screened for HIV of whom only 198 were HIV-negative. These HIV-negative women were monitored monthly over a period of 3 years. Of the women who seroconverted (became HIV-positive), all but 6 became HSV-2 positive before they became HIV-1 positive. The data suggest that immediately after infection with HSV-2, the risk of contracting HIV-1 increases significantly

A seemingly paradoxical finding is that women who were already HSV-2 positive at the start of the study had a significantly lower incidence of HIV, while women who got HSV-2 during the trial had a higher incidence of HIV.

A possible explanation of this finding, says the Policy Brief, is that women previously exposed to HSV-2 may be protected from super-infection with the circulant HSV-2. There is strong evidence that HSV-2 reinfection does not occur. This reduced their risk of acquiring new HSV-2 infection and thus of getting ulcers and sores which are a risk factor for HIV-1. This paradoxical finding requires further investigation. The study also suggests an urgent need to develop HSV-2 vaccines.

Recommendations

There is an urgent need to recognise HSV-2 infection among populations at risk, especially the young, and to provide treatment and counselling on condom use. Results from a recent study have shown that condoms can effectively reduce HSV-2 transmission.

Identification of new HSV-2 infection in pregnancy may indirectly impact on mother-to-child transmission of HIV-1

While rapid tests for HIV-1 and syphilis are available, no such tests are available for HSV-2 screening. Priority should be given to the development of rapid HSV-2-specific tests.

There is a need to integrate HSV-2 and HIV-1 prevention efforts in all countries at risk of increasing HIV-1 infections.

Intensive efforts and funding are currently invested in the development of an HIV-1 vaccine. This study has shown that equally, there is an urgent need to develop an HSV-2 vaccine in order to curb the spread of both HIV-1 and HSV-2.

 

November 2002