WEDNESDAY, Jan. 20 (HealthDay News) -- The use of acyclovir to suppress herpes simplex 2 (HSV-2) infection does not appear to reduce the risk of transmission of HIV-1 from infected individuals to uninfected heterosexual partners, according to research published online Jan. 20 in the New England Journal of Medicine.
Connie Celum, M.D., of the University of Washington in Seattle, and colleagues analyzed data from 3,408 heterosexual couples from sites around Africa. In each couple, one partner was infected with HSV-2 and seropositive for HIV-1, with a CD4 count of at least 250 cells per cubic ml, and the other partner was uninfected with HIV-1. The infected partner took 400 mg of oral acyclovir twice daily or placebo for up to 24 months.
Of the seroconversions to HIV-1 in uninfected partners, the researchers found that 84 transmissions were linked to the infected partner. These were divided roughly equally between the treatment and placebo groups (41 and 43, respectively), leading to a statistically insignificant difference. However, treatment reduced the plasma concentration of HIV-1 by 0.25 log10 copies per ml and the occurrence of HSV-2 positive genital ulcers by 73 percent.
"The lack of efficacy of HSV-2 suppressive therapy in preventing the transmission of HIV-1 among participants in this study does not appear to have been caused by poor activity of acyclovir against HSV-2 or by poor adherence to treatment," the authors write. "New strategies to reduce the risk of transmission of HIV-1 are needed for HIV-1-serodiscordant couples."
Several co-authors reported financial relationships with pharmaceutical companies.