Inactivation of Herpesvirus hominis Types 1 and 2 by Silver Nitrate In Vitro and In Vivo

Herpes simplex virus (HSV) types 1 and 2 (two strains each) were inactivated at different rates in vitro by 40 μM AgNO3 . The inactivation of HSV type 1 strains was virtually complete in 10 to 15 min, whereas almost half of the infectivity of HSV type 2 strains survived this exposure. One strain of type 1 inoculated into rabbit eyes was almost completely inactivated by 1% AgNO3 solution dropped into the eye 20 min later, so that there was markedly reduced viral replication and less corneal herpetic disease. One strain of HSV type 2 in the rabbit eye was not effectively inactivated by 1% AgNO3 . From these results, it seems likely that AgNO3 instillation into the eyes of a newborn who has passed through a birth canal infected with HSV might prevent eye infection with HSV type 1 but not with type 2. The greater resistance of HSV type 2 strains to chemical inactivation in vitro and in vivo may be of medical concern.