Infectious hepatitis; attempts to infect rodents and to isolate virus in tissue cultures.

The paper describes continued efforts to isolate the virus of infectious hepatitis. Experiments include a search for naturally-occurring hepatitis among wild rodents indigenous to Southern Ontario, captured in the proximity to the homes of human cases. Attempts have been made to infect similar animals with the faecal extracts and sera from human cases. Suckling mice were inoculated with infective material and tissue emulsions serially propagated for a period of over one year. Efforts to cultivate the virus in tissue culture of monkey liver, spleen, and lung are described in detail. A search for specific complement-fixing antibodies in convalescent sera and for haemagglutinins in inoculated tissue culture fluids has proved negative.