Serologic Survey for Encephalomyocarditis Virus in Zoological Institutions Throughout the United States and Canada
Encephalomyocarditis virus, a cardiovirus in the Picornaviridae, has a worldwide distribution and can result in disease in a broad range of species.1,2,4 The virus was first isolated in the 1940s and has been responsible for multiple deaths throughout zoological collections. In the United States, most cases have been isolated to the gulf coast states. Historically, disease has been seen in hoofstock, particularly Proboscidea and Suidae, and non-human primates.2 While EMCV is considered zoonotic, the disease generally only causes mild symptoms in humans. Transmission is fecal oral and is associated with murine rodent species, which act as the primary reservoir hosts.4 The severity of the disease is variable among different species, ranging from asymptomatic to peracute death. Gross lesions generally are limited to the cardiopulmonary system and include pulmonary edema, pale streaks throughout the myocardium and pericardial effusion. In an effort to determine the extent of exposure of zoological collections to the virus throughout the United States and Canada, a serosurvey focusing primarily on hoofstock species was undertaken. Serum samples were solicited from zoos across the country and submitted to the Texas Veterinary Medical Diagnostic Laboratory for routine serologic screening for EMCV using serum neutralization. Thirty-five institutions provided samples for screening representing 49 species. Twenty-seven institutions replied to a written survey of EMCV cases. Of these, six (2%) reported previous outbreaks or suspicious deaths associated with encephalomyocarditis.
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