Abstract
Cytopatho-genesis was observed in hamster kidney tissue cultures infected with eastern equine (EEE) western equine (WEE), Venezuelan equine (VEE), St. Louis, Japanese B, and Murray Valley encephalitis viruses and by Ilheus and West Nile viruses. The sensitivity of these tissue cultures was equal or superior to that of mice. Guinea pig kidney and chick embryo cultures reacted with complete cytopathic effects only with EEE, WEE, and VEE viruses.