Iododeoxyuridine and herpesviral encephalitis: lack of inhibitory action against low-grade viral replication.

Equine herpesvirus 1 replicated in the brains of 2-week-old mice but did not produce fatal encephalitis; it thus simulated the majority of cases of herpes simplex encephalitis in man. This replication was not inhibited by iododeoxyuridine, although in tissue cultures the equine and human viruses were equally susceptible. The continued use of iododeoxyuridine for human encephalitis should be seriously questioned.