Characterization of an antigen-antibody system associated with epidemic non-A,non-B hepatitis in west africa and experimental transmission of an infectious agent to primates

An epidemic of non-A, non-B hepatitis (NANBH) was studied in Tortiya, Ivory Coast, over a period of 17 months. Highly sensitive serologic tests performed on serum samples from patients with this type of hepatitis excluded both HAV (hepatitis A virus) and HBV (hepatitis B virus) as aetiologic agents. The mode of spread of the epidemic, clinical features and frequent cases of fulminant hepatitis in pregnant women resembled that of other recently described water-borne outbreaks of non-A,non-B hepatitis. Oral-faecal transmission of this form of NANBH was shown by experimental infection of African monkeys, which developed antibody of the IgM class specifically reacting with the antigen present in stools of infected persons. Using the immunoenzymatic test employing monkey IgM on solid phase and enzyme-labelled IgG purified from sera of patients convalescing from NANBH, we identified the antigen associated with the possible causative NANBH agent. These data confirm the existence of a distinct human NANBH agent responsible for epidemic out-breaks of NANBH. This agent is different from those of the postransfusion type of NANBH and antigenically unrelated to HAV. The direct serologic test presented here may be useful for diagnosis of an epidemic form of NANBH.