Comparison of the therapeutic effects of five antiviral agents on cutaneous herpesvirus infection in guinea pigs.

Cutaneous herpesvirus infection of guinea pigs has been evaluated as a model for testing antiviral compounds. Six infected sites on each animal can be used independently for local treatment. The severity of the infection has been graded in a score system. The cumulative scores during infection and the time to healing can be used to determine antiviral effects. The effects of adenine arabinoside, cytosine arabinoside, iododeoxyuridine, ribavirin and phosphonoacetic acid on the cutaneous infection was compared. Phosphonoacetic acid was the only compound with a good therapeutic activity against herpesvirus infection, causing a reduction of both the cumulative score and the time to healing. Phosphonoacetic acid was skin irritating at 2 per cent, but at 1 per cent, which still had a good therapeutic activity, skin irritation was seen only occasionally.