Background: Several studies suggest that herpes simplex virus type 2 (HSV-2) may enhance HIV-1 transmission and disease progression.
Methods: We conducted a randomized, double-blind, placebo-controlled trial of aciclovir 400 mg twice daily for 3 months in 300 HSV-2/HIV-1 co-infected women not yet on highly active antiretroviral therapy (HAART). Participants were evaluated prerandomization and at monthly visits for 3 months. Primary outcomes were the detection and quantity of genital HIV-1 RNA at the month 3 (M3) visit. Analyses were also undertaken using data from all visits. The treatment effects on plasma HIV-1 RNA, CD4 cell count and genital HSV-2 DNA were also assessed.
Results: At M3 fewer women had detectable genital HIV in the aciclovir group compared to placebo, but this was not significant [61/132 (46%) vs. 71/137 (52%), risk ratio (RR) 0.89, 95% confidence interval (CI) 0.70-1.14; P = 0.36]. There was also little difference in quantity of HIV-1 RNA among shedders (+0.13 log10 copies/ml, 95% CI -0.14 to 0.39) at M3. However, aciclovir significantly decreased the frequency of HIV-1 shedding over all visits [adjusted odds ratio (OR) 0.57, 95% CI 0.36-0.89]. Significant reductions in M3 plasma HIV-1 RNA (-0.34 log10 copies/ml, 95% CI 0.15-0.54), genital HSV-2 DNA (8 vs. 20%, RR 0.37, 95% CI 0.19-0.73) and genital ulceration (8 vs. 18%, RR 0.43, 95% CI 0.22-0.84) were observed in the aciclovir group.
Conclusion: HSV-2 suppressive therapy, by reducing HIV-1 plasma viral load and altering the pattern of genital HIV-1 shedding, may contribute to the reduction in sexual transmission of HIV-1 and may delay the requirement for HAART initiation.