Studies on the agent of infectious hepatitis; propagation of the agent in tissue culture and in the embryonated hen's egg.

Two viral agents have been procured from patients with infectious hepatitisin two widely separated outbreaks of the disease by transfer of acute stage serum and stool filtrates to and passage in tissue cultures of rabbit liver cells in roller tubes and minced chick embryos in Simms-Sanders medium followed by passage in the amniotic cavity of the chick. Cultures of both agents, designated the Akiba and NL strains of virus, induced mild hepatitis without jaundice in the majority of volunteers tested after an incubation period of from 9 to 38 days. Although these agents have not been identified definitely as the virus of infectious hepatitis, the available evidence, as discussed, is compatible with the suggestion that such they are.