Zoonotic monkey B virus (Macacine alphaherpesvirus 1; BV)
infections are extremely serious and usually fatal. Drugs currently used for treatment were developed for the treatment of herpes simplex virus but are less effective against BV. Effective suppression of viral replication in the skin could prevent the virus from invading the nervous system. To test this hypothesis, the efficacy of
topical administration of several drugs against lethal BV
infection was evaluated in female BALB/c mice that were infected by scarification. Drugs were then applied to the site of inoculation. As 3% preparations, most drugs were only minimally effective or ineffective. In contrast,
ganciclovir and
cidofovir were very effective. The ED50 for
cidofovir was 0.007%, compared with 1.1% for
ganciclovir. At 0.5%,
cidofovir protected against both death and
neurologic signs, whereas 5%
ganciclovir only protected against death but not neurologic involvement. All genotypes of BV were equally susceptible to
cidofovir and
ganciclovir. For maximal effectiveness, treatment with both
cidofovir and
ganciclovir had to be initiated within 8 h of
infection.
Cidofovir was completely protective when administered only on the day of
infection, whereas a minimum of 5 d of treatment was required for maximal
ganciclovir efficacy. These studies showed that topical
cidofovir treatment started soon after BV exposure was very effective in preventing BV from invading the nervous system, whereas
ganciclovir treatment was only partially effective. In addition,
cidofovir was protective against a
ganciclovir-resistant BV mutant, whereas
ganciclovir was not. These studies showed that topical
cidofovir treatment started soon after BV exposure is more effective than
ganciclovir in preventing BV from invading the CNS.