Nonhuman primate-associated viral hepatitis type A. Serologic evidence of hepatitis A virus infection.

Since 1961, viral hepatitis has been recognized as an occupational hazard among handlers of newly imported chimpanzees and other nonhuman primates. To determine whether previously reported cases were caused by human viral hepatitis type A, we tested paired serum samples from two outbreaks for antibody to hepatitis A antigen (anti-HA) by immune adherence hemagglutination (IAHA), recently available test. In both outbreaks, one of hepatitis transmitted from chimpanzee to man (Michigan, 1964), the second from chimpanzee to chimpanzee, man, and woolly monkey (Connecticut, 1971), serologic data documented recent hepatitis A virus infection among contacts-human and nonhuman primate-of implicated chimpanzees. This confirms serologically a previously noted epidemiologic association between nonhuman primate-associated hepatitis and human viral hepatitis, type A.