Effect of ribavirin on murine cytomegalovirus infection.

Ribavirin (1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide), a new synthetic nucleoside, inhibited murine cytomegalovirus in cell culture. This was shown by the inhibition of viral cytopathic effect and plaque formation, as well as reduction in the yield of virus. Despite this in vitro antiviral effect, ribavirin did not protect mice from mortality produced by a high inoculum of cytomegalovirus. When a lower inoculum was used to initiate a chronic infection, the administration of ribavirin for 9 days had no effect on the titer of cytomegalovirus in the salivary gland, kidney, liver, and spleen. Thus, ribavirin was ineffective in the treatment of both acute and chronic murine cytomegalovirus infections.