Scientists say treating genital herpes, which is rampant throughout sub-Saharan Africa, does not prevent the spread of the virus that causes AIDS.  But researchers remain convinced that genital herpes, a sexually transmitted disease, makes people more vulnerable to HIV.  VOA's Jessica Berman reports.

Experts say between 50 and 80 percent of people who live in sub-Saharan Africa are infected with the sexually transmitted virus herpes simplex 2, known as genital herpes, by the time they reach the age 35.  In the same region, 90 percent of the people who are HIV positive are infected with genital herpes. 

Herpes simplex is not deadly, but like HIV, is not curable.  It can only be suppressed with anti-viral drugs.

Researchers point to studies that show herpes-simplex infection increases the risk of acquiring HIV by three-fold.  The researchers tried to show treating individuals with genital herpes would make them less vulnerable to infection with the deadly AIDS virus.

Stephen Lagakos is a professor of biostatistics at Harvard University in Cambridge, Massachusetts.  

"The motivation was sound," he said.  "I think the quality of the study from what I could tell from reading the paper was very good.  The investigators are very good investigators, and they failed to show a benefit."

The study, reported this week in the New England Journal of Medicine, involved a group of 800 women in Tanzania between the ages of 16 and 35 infected with herpes simplex. 

None of the women was infected with HIV.

Half of the women were given a common antiviral drug called acyclovir to suppress their genital herpes infection.  The other half took sugar pills.  At the conclusion of the study, 27 women in the acyclovir treated group were infected with HIV and there were 28 new HIV infections in the untreated group of women.

Debby Jones-Watson is a senior clinical investigator at the London School of Hygiene and Tropical Medicine and the study's lead author.  Jones-Watson is not ready to give up on the research. 

"The actual anti-viral used, acyclovir, is very good for managing routine herpes cases in clinics, but may not be perhaps at this dosage potent enough to switch off the HSV [herpes simplex virus] mechanisms in the body that might increase susceptibility to HIV infection," she noted.

Investigators are now looking at other ways to suppress genital herpes for longer periods of time that they hope will provide protection against HIV.

Experts say a number of other studies are underway to see whether using acyclovir to treat genital herpes in HIV-infected individuals prevents the spread of the AIDS virus to their uninfected partners.