Ganglionic herpes simplex and systemic acyclovir.

The therapeutic and systemic effects of acyclovir on ganglionic herpes simplex virus (HSV) in mice were studied by varying the duration of treatment and the time of removal of ganglia for co-cultivation after treatment had ended. When treatment was started three hours after infection, it had a significant therapeutic effect even when the ganglionic culture was delayed 17 days after the end of acyclovir therapy. When treatment was started 24 hours after infection, it had no significant effect under the same circumstances. The treatment of established latent ganglionic HSV for 15 days with acyclovir had a significant therapeutic effect compared with control mice when ganglia were cultured two days after treatment had ended, but this effect was lost by ten and 21 days after the end of therapy. This indicates that acyclovir has a transient suppressive effect on part of the viral ganglionic reservoir, but it also indicates that these titers quickly reestablish themselves with the removal of drug therapy.