ENCEPHALOMYOCARDITIS VIRUS-INFECTIONS IN AN AUSTRALIAN ZOO

Fatal encephalomyocarditis virus (EMCV) infections in a ring-tailed le mur (Lemur catta), a squirrel monkey (Saimiri sciureus), three mandril ls (Mandrillus sphinx), a chimpanzee (Pan troglodytes), a pygmy hippop otamus (Choeropsis liberiensis), and two Goodfellows tree kangaroos (D endrolagus goodfellowi) occurred at Taronga Zoo. This is the first des cription of EMCV in a zoological collection outside of the United Stat es. Regardless of species, the most common clinical presentation was s udden death. The gross pathologic changes were diffuse or focal pallor of the myocardium with occasional marked pulmonary congestion. Necrot izing nonsuppurative myocarditis was consistently present. EMCV was is olated from only one of 54 feral rodents examined. No antibodies to EM CV were detected with a serum neutralization test in 79 stored sera fr om a wide variety of zoo mammals. Titers of 1:16, 1:16, and 1:4 were r ecorded for a spider monkey (Aeteles geoffroyi), a lion (Panthera lee) , and an orangutan (Pongo pygmaeus), respectively. Of seven mandrills tested in 1988, six had measurable virus titers. Later testing indicat ed that these titers did not persist, and one mandrill with a titer >1 :128 in 1988 subsequently succumbed to EMCV infection in 1991.