A New Transmissible Viral Hepatitis of Marmosets and Tamarins

Callitrichid hepatitis (CH) is a newly recognized, acute, fatal, epizootic disease of New World primates in the family Callitrichidae. Since 1980, 12 outbreaks of CH have occurred in US zoos, involving several callitrichid species including the endangered golden lion tamarin (Leontopithecus rosalia). CH was experimentally transmitted to common marmosets via a bacteria-free filtrate of liver from a naturally infected tamarin. All three inoculated marmosets developed an acute fatal disease with the characteristic clinical and histopathologic findings of CH. Human hepatotropic viruses that can infect the livers of callitrichids were not detected serologically in any of the experimentally infected marmosets. Enveloped viruslike particles 85–105 nm in diameter were observed in the rough endoplasmic reticulum and Golgi complex of hepatocytes from both naturally infected and experimentally inoculated animals. An immunoblot assay was developed using sera from tamarins exposed to natural outbreaks of CH and liver extracts from experimentally infected or control marmosets. A new CH-specific antigen was detected in the livers of naturally infected and experimentally inoculated marmosets but not controls. These results suggest that the etiologic agent of callitrichid hepatitis is a new primate hepatitis virus.