PATHOLOGY AND IMMUNOHISTOCHEMISTRY OF CALLITRICHID HEPATITIS, AN EMERGING DISEASE OF CAPTIVE NEW-WORLD PRIMATES CAUSED BY LYMPHOCYTIC CHORIOMENINGITIS VIRUS

Callitrichid hepatitis is an arenavirus infection that recently emerge d as a highly fatal disease of New World primates in the Callitrichida e family. As we previously reported, these primates develop hepatitis after contact with mice that are infected with variants of LCMV (LCMV( CH)), recently determined to have 86% identity with GC-P gene of the A rmstrong and Western strains of LCMV. Here, we describe the histopatho logical lesions and tissue localization of viral antigens in confirmed cases of callitrichid hepatitis from recent outbreaks in two U.S. zoo s. The liver in marmosets and tamarins with fatal infections consisten tly showed degeneration, necrosis, and inflammation, with variable inv olvement of the spleen, lymph nodes, adrenal glands, intestine, pancre as, and central nervous system. Lymphocytic choriomeningitis virus ant igens were identified immunohistochemically in necrotic foci in these organs as well as in nondegenerating areas in lungs, kidneys, urinary bladder, brain, and testes. The multi-organ tropism and histological p attern of LCMV infection in marmosets and tamarins are similar to thos e reported for the highly virulent arenavirus that causes lassa fever in humans. Comparative studies of callitrichid hepatitis and Lassa fev er would therefore be mutually beneficial for human and nonhuman prima te medicine.