602 an Infectious Hepatitis of Undetermined Origin

Experiments with volunteers have established the viral etiology of human hepatitis. Several species of animals are susceptible to hepatitis caused by viruses which appear to differ from each other and from the virus or viruses infecting man. Horses (1--4) may develop hepatitis following the inoculation of homologous serum. Swine (5, 6), dogs (7, 8), and birds (9) are all susceptible to epizootics of virus hepatitis. A form of hepatitis in old mice, which appears to be non-transmissible and produces no gross signs of disease was described by Olitsky and Casals (10) and others (11-13). This hepatitis is characterized by the occurrence of cytoplasmic inclusion bodies. Gledhill and Andrewes (14-16) have described hepatitis in mice due to a mouse hepatitis virus which occurred in their stock mouse colony and was transmissible to sucking mice proving fatal to them. Nelson (17-20) has described a somewhat similar acute disease in mice, with an associated leukemia and Japanese workers have encountered a similar disease (21-24). Each of these animal diseases appears to be due to a different virus but none to the agent causing hepatitis in man. Many unsuccessful attempts to adapt the human virus to an animal host have been published (25-27).