Encephalomyocarditis virus infection in an Italian zoo

Abstract

A fatal Encephalomyocarditis virus (EMCV) infection epidemic involving fifteen primates occurred between October 2006 and February 2007 at the Natura Viva Zoo. This large open-field zoo park located near Lake Garda in Northern Italy hosts one thousand animals belonging to one hundred and fifty different species, including various lemur species. This lemur collection is the most relevant and rich in Italy. A second outbreak between September and November 2008 involved three lemurs. In all cases, the clinical signs were sudden deaths generally without any evident symptoms or only with mild unspecific clinical signs. Gross pathologic changes were characterized by myocarditis (diffuse or focal pallor of the myocardium), pulmonary congestion, emphysema, oedema and thoracic fluid. The EMCV was isolated and recognized as the causative agent of both outbreaks. The first outbreak in particular was associated with a rodent plague, confirming that rats are an important risk factor for the occurrence of the EMCV infection.

Retrospective genetic characterisation of Encephalomyocarditis viruses from African elephant and swine recovers two distinct lineages in South Africa

“…Whereas numerous strains have been isolated and characterised globally from outbreaks in domestic pigs (Maurice et al 2005) and from putative murid rodent hosts in close proximity (Billinis 2009), reports of the disease in wild and exotic animals are sporadic and generally limited to captive populations in North America, Australia and Europe and their associated rodent populations (Wells et al 1989;Redacliff et al 1997;Canelli et al 2010). In contrast, Africa is the only continent from which outbreaks of the disease have been reported from a population of semi-wild primates (Jones et al 2011) or from a natural population of elephants (Grobler et al 1995).…”

“…Clinical outcomes range from inapparent, to acute and highly lethal infections (Thomson et al 2001). Aside from outbreaks in pigs (Knowles et al 1998;Maurice et al 2005;Denis et al 2006), sporadic outbreaks are recorded in zoos and invariably affect a wide range of species (Reddacliff et al 1997, Canelli et al 2010, however, primates and elephants appear to be particularly susceptible (Simpson et al 1977, Tesh & Wallace 1978, Seaman & Finnie 1987, Jones et al 2011. Murids are generally considered to be the virus reservoir hosts (Zimmerman 1994, Thomson et al, 2001), but a possible role for wild boars in the epidemiology of the disease in domestic pigs in Europe, has been suggested (Billinis 2009).…”

Encephalomyocarditis virus in a captive Malayan tapir (<i>Tapirus indicus</i>)

“…Since the toxicology lab did not find any of the ionophores that could be involved in Belgium (maduromicin, narasin, lasalocid, monensin, salinomycin, semduramicin) in the liver tissue, this possibility was also excluded. Outbreaks of encephalomyocarditis virus are notorious for their suddenness and many cases occur as asymptomatic deaths both in zoo mammals and in young domestic pigs (Wells et al, 1989;Reddacliff et al, 1997;Gelmetti et al, 2006;Vogelnest et al, 2006;Canelli et al, 2010;Yeo et al, 2013). In our case, the Malayan tapir died suddenly without any predictive symptoms.…”

“…There is no descriptive report on encephalomyocarditis virus (EMCV) in tapirs in the international literature, but the occurrence of this disease is mentioned in the Tapir (Tapiridae) Care Manual of the Association of Zoos and Aquariums (2013) and two cases were mentioned briefly by Janssen et al (1996). Yet, several publications exist of EMCV in other mammal species in zoological collections (Wells et al, 1989;Reddacliff et al, 1997;Vogelnest et al, 2006;Canelli et al, 2010;Liu et al, 2013;Yeo et al, 2013). The present report describes the gross necropsy, histopathology and ancillary laboratory examinations of a fatal EMCV infection in a young captive Malayan tapir.…”

“…Vitamin E / selenium deficiency is a well-known condition in domestic and zoo animals (Valentine et al, 2002;Liesegang and Baumgartner, 2004;Katz et al, 2009). Vitamin E and selenium values are unknown in normal tapir liver, but reference ranges for domestic horses are 10 -40 µg/g and 0.7 -2.0 µg/g dry weight, respectively (Yamini and Schillhorn van Veen, 1988;Finno et al, 2006;Barigye et al, 2007). A Brazilian tapir (Tapirus terrestris) with nutritional myopathy showing pale skeletal muscles and a pale myocard had a critically low hepatic vitamin E value of 1.3 µg/g and a normal selenium value of 1.20 µg/g dry weight (Yamini et al, 1988).…”