Prevalence of hepatitis B virus infections in nonhuman primates

The aim of this study was to determine the prevalence of hepatitis B virus (HBV) infection in nonhuman primates. Serum samples from Europe, Thailand a nd Vietnam were analyzed. Sera obtained from 262 apes and 454 monkeys were tested for HBV infection serologically and for HBV DNA using nested PCR (nP CR). A total number of 198 ape sera and all but one (Cercopithecus aethiops ) of the 4543 monkey sera had no serological signs of HBV infection. Among the 64 of 262 (24.4%) seropositive ape sera, we found, as in humans, differ ent stages of HBV infection: very early HBV infection, active infection wit h high level of infectivity, virus carriers with low infectivity, and passe d HBV infection. In the cases with passed infection, 47.8% harbored HBV DNA in the presence of protective antibodies to the HBV surface antigen (HBsAb ). This indicates HBV persistence in apes despite immune control. in contra st to apes, in monkeys HBV infection is a very rare event.