Epstein-Barr virus infection of HIV-seropositive individuals is transiently suppressed by high-dose acyclovir treatment.

Objective: To assess whether oral acyclovir can eliminate persistent Epstein-Barr virus (EBV) infection and thereby prevent EBV-associated lymphoma development in HIV-seropositive homosexual men.
Method: Persistent EBV infection was examined in a group of 21 HIV-seropositive homosexual men before, during and after treatment with oral acyclovir at a dose of 800 mg every 6 h (10 individuals) or with a placebo (11 individuals).
Results: In 13 individuals, EBV was isolated from the oropharynx before and after treatment (seven cases from the acyclovir-treated group and six from the placebo-treated group). A significant reduction in virus isolation occurred during treatment in the acyclovir-treated group, but not in the placebo-treated group. In seven cases in whom EBV shedding was detected before and after treatment, the EBV strain isolated was identical throughout the study, even when acyclovir had abolished detectable shedding for the duration of the treatment. In two other cases more than one strain was detected. On examination of the EBV type present, 89% of a group of 18 patients consistently shed type A virus, 5.5% type B virus and 5.5% showed evidence of co-infection with both virus types. This compares with figures of 100, 0 and 0%, respectively, in a control group of HIV-seronegative individuals.
Conclusions: High-dose acyclovir therapy does not eliminate persistent EBV infection from the oropharynx of healthy HIV-seropositive individuals and therefore would not necessarily prevent lymphoma development. Our results suggest that infection by type B EBV, and co-infections of both A and B type, are more common in HIV-seropositives than HIV-seronegatives.