These are the findings of a study published in today’s New England Journal of Medicine.
The research was conducted in Burkina-Faso in Africa and took the form of a randomized, double-blind placebo-controlled trial.
Valocyclovir is marketed by GlaxoSmithKline as Valtrex.
Dr Nicolas Nagot of the London School of Hygiene and Tropical Medicine and colleagues found that treating herpes simplex 2 (HSV-2) infections with valocyclovir reduced levels of HIV-1 RNA in both the blood plasma and the genital mucosa, with the latter being more significant.
And this effect seemed to get stronger over the three months of the study.
Once a woman has herpes, the risk of getting HIV is increased and other research studies have shown that when HSV-2 is present it increases the amount of HIV-1 in plasma and genital mucosa.
The study enrolled 140 women who were tested positive for HIV-1 and HSV-2 and were not eligible for highly active antiretroviral therapy.
The participants’ levels of HIV and herpes were monitored for 24 weeks; 12 before and 12 after being randomly assigned to either the placebo or the valocyclovir treatment group.
The scientists then used statistical regression anaylsis to to work out the effect of the treatment on the genital and plasma viral loads of HIV-1 (RNA) and HSV-2 (DNA) over the period of the study. Of the 140 women enrolled, 136 were included in the analysis.
The scientists found that the group on valacyclovir showed a significant decrease in the level of HIV viral load in the genital and plasma samples, at least 50 per cent on average. There was no significant reduction in detection of HIV though, so the effect of the antiviral was to reduce rather than eliminate HIV activity.
When they analysed the repeated measures over time, the researchers found that the effects became significantly stronger over the period of the study.
Dr Nagot and colleagues concluded that “HSV suppressive therapy significantly reduces genital and plasma HIV-1 RNA levels in dually infected women.”
“This finding may have important implications for HIV control,” they said.
They also suggested that while treatment for herpes might never give full protection against HIV, it should reduce transmission through sexual intercourse, because it reduces the strength of genital HIV. Also, by reducing the plasma level of HIV, herpes treatment in dual infected patients gives them more time before they need to start the antiviral therapy.
In the same edition of the journal there is a commentary by Dr Larry Corey, Principal Investigator of the HIV Vaccine Trials Network at the Fred Hutchinson Cancer Research Center, and head of the Infectious Diseases Program and Virology Division at the University of Washington, in Seattle.
Dr Corey urged clinicians to do more routine testing for herpes simplex 2 during their initial assessment of HIV-positive patients. He said that the paper written by Dr Nagot and colleagues has “direct clinical implications, suggesting that HIV-1 replication can be reduced with antiviral therapy directed solely at HSV-2.”
Dr Corey is the author of an earlier study where he suggested that people who are infected with sexually transmitted HIV have a higher than usual rate of HSV-2 infection as well. He estimated the co-infection rate to be 30 to 70 per cent for Europeans and 50 to 90 per cent for Africans.
“Reduction of HIV-1 RNA Levels with Therapy to Suppress Herpes Simplex Virus.”
Nicolas Nagot, Abdoulaye Ouédraogo, Vincent Foulongne, Issouf Konaté, Helen A. Weiss, Laurence Vergne, Marie-Christine Defer, Didier Djagbaré, Anselme Sanon, Jean-Baptiste Andonaba, Pierre Becquart, Michel Segondy, Roselyne Vallo, Adrien Sawadogo, Philippe Van de Perre, and Philippe Mayaud.
NEJM Volume 356:790-799, February 22, 2007, Number 8
Written by: Catharine Paddock
Writer: Medical News Today