Herpesvirus hominis infection in newborn mice: comparison of the therapeutic efficacy of 1-beta-D-arabinofuranosylcytosine and 9-beta-D-arabinofuranosyladenine.

Intranasal inoculation of newborn mice with Herpesvirus hominis type 2 provides an experimental infection that closely resembles disseminated herpesvirus infection of human newborn infants. After inoculation of mice, the virus multiplies in the respiratory tract and is disseminated through the blood to the liver and spleen and to the brain by both a viremia and nerve route transmission. Although therapy with 1-beta-d-arabinofuranosylcytosine (ara-C) did not reduce final mortality, it did increase the mean survival time by 1 day. This effect on the mean survival time was associated with a 1-day delay in the appearance of herpesvirus in the blood, liver, and spleen and a reduction of virus replication in lung and brain for 1 day as compared with untreated control animals. Treatment with 9-beta-d-arabinofuranosyladenine (ara-A) likewise had no effect on final mortality, but increased the mean survival time by 2 days. Therapy with ara-A delayed or suppressed virus replication in blood, lung, liver, spleen, and brain for 2 days. Although treatment with either ara-C or ara-A in this experimental H. hominis type 2 infection resulted in a temporary delay and/or suppression of viral replication in several target organs, neither compound was completely effective in inhibiting viral replication or in protecting animals from eventual death due to the infection.