Experts call for HSV control measures, including vaccine, to rank high on international HIV prevention and research agenda as exciting trial findings are published.
Treating women who are infected with both the HSV-2 and HIV viruses with anti-herpes treatment can reduce the amount of HIV in the blood and genital secretions, according to the results of a trial published in the New England Journal of Medicine.
A collaborative group of scientists from the Centre Muraz (Burkina Faso), the University of Montpellier (France) and the London School of Hygiene & Tropical Medicine (UK) carried out the trial among women co-infected with the human immuno-deficiency virus (HIV) and the virus that causes genital herpes (HSV-2) in Burkina Faso. The results showed that having the herpes virus increased the replication of HIV, and also revealed that the quantity of HIV in the blood and in the vagina was reduced by continuous anti-herpes treatment over 3 months.
These findings open new avenues for the prevention of HIV transmission and for the management of patients co-infected by the two viruses.
In 2005, an estimated 4.1 million people were newly infected with HIV, mostly through heterosexual intercourse1. This alarming number of infections highlights the urgent need to intensify and expand proven prevention methods, and further, to identify and implement new methods of HIV prevention.
A number of observational studies have indicated that HSV-2 enhances the risk of HIV-1 acquisition by around three-fold2. HSV-2 infection may also increase HIV-1 infectiousness by disrupting the genital mucosa and increasing the levels of HIV in the genital tract3, allowing easier transmissibility of the virus. In addition, the HIV viral load in the blood of HIV-1 infected patients increases, at least temporarily, during episodes of HSV reactivation.
Lead author Dr. Nicolas Nagot, of the London School of Hygiene & Tropical Medicine (LSHTM), explains: 'Behavioural interventions are not always successful, as knowledge does not necessarily translate into sexual behaviour change. Therefore, innovative methods that target the biological susceptibility of individuals to acquire or transmit HIV are also required. A number of options to prevent HIV transmission are currently being investigated, including the role of vaginal microbicides, pre-exposure HIV prophylaxis, male circumcision, and - in the future - an HIV vaccine.'