Recently, an autopsy report from the Indian Veterinary Research Institute revealed that a lone African elephant at the National Zoological Park in Delhi died due to the rare rodent-borne virus — encephalomyocarditis virus (EMCV).

Encephalomyocarditis Virus (EMCV) key points:

• EMCV is a small, non-enveloped, positive-sense single-stranded RNA virus belonging to the Cardiovirus genus and Picornaviridae family.
• It causes encephalomyocarditis, a disease involving myocarditis (heart inflammation), encephalitis (brain inflammation), neurological diseases, reproductive disorders, and diabetes in many mammalian species.
• Pigs are highly susceptible to EMCV and often develop acute myocarditis leading to sudden death; mortality can be very high in young piglets.
• The virus is also known to infect other mammals, including zoo animals like African elephants, and humans, although human infections are rare and usually asymptomatic.
• EMCV is transmitted primarily via contamination from feces or urine of infected rodents, which are considered the natural reservoir.
• Infected pigs show symptoms like fever, respiratory distress, sudden death, and reproductive failures such as abortions.
• Diagnosis depends on virus isolation, PCR assays, and immunohistochemical testing; single serum antibody tests are less reliable due to subclinical infections.
• There is no specific treatment; supportive care is given to manage symptoms and complications.
• EMCV is used as a model virus in immunology research, particularly in studying immune responses like Toll-like receptor signaling.
• The virus’s ability to evade host immune responses contributes to its virulence.
• EMCV has zoonotic potential, with human infections occurring mainly via fecal-oral routes, but severe human disease is rare.
• Pathological findings in animals include myocarditis with necrotic lesions in the heart, meningeal inflammation in the brain, pulmonary edema, and fluid accumulation in body cavities.
• Outbreaks in captive and wild animals have been reported globally, raising concerns especially in veterinary and conservation contexts.

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