A New Transmissible Viral Hepatitis of Marmosets and Tamarins

Abstract

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.

A Common-Source Outbreak of Callitrichid Hepatitis in Captive Tamarins and Marmosets

“…Neither person experienced any illness at the time of exposure [4]. Nevertheless, considerable caution is strongly recommended for veterinary staff exposed to infected primates or their tissues and excreta.…”

“…Solid-phase and iinmunoblot immunoassays. Frozen liver samples from the affected tamarins and marmosets, mice, a control common marmoset, and a common marmoset experimentally inoculated with LCMVCH [4] were homogenized in TEN (lOmMTRIS, I miWEDTA. ISOmA^NaCI, pH 7.4)andcentrifuged at 1000 g; the supernatants were respun at 12,000 g and the resultant pellets resuspended in TEN with 0.5% (vol/vol) NP-40.…”

“…ISOmA^NaCI, pH 7.4)andcentrifuged at 1000 g; the supernatants were respun at 12,000 g and the resultant pellets resuspended in TEN with 0.5% (vol/vol) NP-40. Dot blots were done [4] with convalescent serum from a tamarin surviving a previous outbreak and polyclonal anti-LCMVARM guinea pig serum. SDS-PAGE and immunoblots were done [8] using the above sera and monoclonal antibody 33.3, specific for LCMV gp2.…”

“…We showed that callitrichid hepatitis (CH) was caused by a virus [4] and that this virus, originally designated callitrichid hepatitis virus, was an arenavirus, lymphocytic chonomeningitis virus (LCMV) [5], Because LCMV is enzootic in Mus musculus woridwide [6], we suspected that mice were a source of the virus initiating CH outbreaks [5]. The modes of introduction and transmission of LCMV in zoos and animal parks, however, had not been determined in any of the previously reported outbreaks This paper reports a new, highly fatal common-source outbreak of CH that occurred in golden lion tamarins and pygmy marmosets {Callithrix pygmaea) at a US zoo…”

The arenaviruses

“…In addition, naturally occurring outbreaks and deaths among captive marmosets and tamarinds have been attributed to infection with lymphocytic choriomeningitis virus following exposure to infected wild mice. 20,21 To the authors' knowledge, the role of nonrodent domestic mammal species (dogs, cats, and livestock) in the transmission of the arenaviruses has not been investigated, but epidemiologic evidence supports their unimportance as reservoirs. Arthropod vectors have not been implicated in the transmission of the arenaviruses.…”