Simultaneous acute infections with hepatitis A and hepatitis B viruses in a chimpanzee.

The unexpected occurrence of a hepatitis B virus (HBV) infection in a chimpanzee experimentally inoculated with hepatitis A virus (HAV) provided an opportunity to examine the course of simultaneous acute infections with both agents. A chimpanzee inoculated intravenously with HAV developed elevated levels of aminotransferases in serum, detectable excretion of hepatitis A antigen in feces, and a marked antibody response to HAV. During the acute phase of this experimentally induced infection with HAV, the chimpanzee simultaneously developed an HBV infection. The latter was characterized by jaundice, a second increase in levels of aminotransferases in serum, and the appearance in serum of hepatitis B surface antigen (HBsAg), hepatitis B e antigen, antibody to hepatitis B core antigen, and, later, antibody to HBsAg. During the acute phase of both HAV and HBV infections, marked histopathologic inflammatory changes were observed in serial liver biopsy specimens. In this chimpanzee, the concurrent acute infection with both HAV and HBV occurred in association with marked liver damage.