Acyclovir and Transmission of HIV-1 From Persons Infected With HIV-1 and HSV-2

"Most persons who are infected with [HIV-1] are also infected with herpes simplex virus type 2 (HSV-2), which is frequently reactivated and is associated with increased plasma and genital levels of HIV-1," wrote the authors. "Therapy to suppress HSV-2 reduces the frequency of reactivation of HSV-2 as well as HIV-1 levels, suggesting that suppression of HSV-2 may reduce the risk of transmission of HIV-1."

At 14 sites in Africa, the researchers enrolled 3,408 couples in which one partner was infected with both HIV-1 and HSV-2 and was not taking antiretroviral therapy at time of enrollment. HIV-positive partners were randomized to receive either a placebo or acyclovir (400mg orally, twice daily). At all visits, participants were given intensive counseling about risk reduction, condoms, and treatment for STDs according to World Health Organization guidelines.

During the study, 132 HIV-1 seroconversions occurred, of which 84 were linked within couples by viral sequencing. Of these, 41 occurred in the acyclovir group and 43 in the placebo group.

"In summary," the authors concluded, "our study of heterosexual HIV-1 serodiscordant couples showed that among the partners who were infected with both HIV-1 and HSV-2 and who had CD4 counts of 250 or more cells per cubic millimeter, treatment with standard doses of acyclovir for the suppression of HSV-2 infection did not decrease the incidence of transmission of HIV-1 to the uninfected partners, despite significant reductions in plasma HIV-1 levels and in the incidence of genital ulcer disease. New strategies to reduce the risk of transmission of HIV-1 are needed for HIV-1 serodiscordant couples."