Daily Current Affairs for UPSC : 4 Nov 2025/Encephalomyocarditis (EMCV) virus: A Rodent-borne diseases

Why in News ?The Delhi zoo’s lone African elephant, Shankar, died of a viral infection that affected his heart, its final post-mortem report has revealed.

The Encephalomyocarditis (EMCV) virus, which causes inflammation of heart muscles, was identified as the cause of death.

About The Encephalomyocarditis (EMCV) virus:

• It is a single stranded, RNA virus that can be classified as non-enveloped and causes multiple diseases in an assortment of mammalian species such as myocarditis, encephalitis, and reproductive disease.
• It is a member of the family Picornaviridae and is capable of being transmitted by rodents that act as natural reservoirs. Swine are the most affected species but some domestic, captive, and wild animals can also be infected.

Viral characteristics:

Type: positive-sense, single-stranded RNA virus

Classification: Cardiovirus genus, Picornaviridae family

Structure: Non-enveloped, icosahedral capsid

Diseases and symptoms :

In animals:

Myocarditis and encephalitis– Inflammation of the heart muscle and inflammation of the brain.

Reproductive disease- In pregnant sows, abortion, stillbirth, and mummified fetuses occur.

Other- In some species, diabetes mellitus may develop and acute and fatal disease can occur, particularly in young animals.

What is rodent born disease?

 Rodent-borne diseases (sometimes mistakenly called “rodent born disease“) are diseases transmitted to humans via rats, mice, squirrels, or other mammals. Rodents may transmit pathogens to humans in a couple of different ways:

1. Bite or scratch (from a rodent)
2. Contact with urine, feces or saliva
3. Inhalation (of contaminated dust)
4. Fleas, ticks or mites living on rodent

Examples of some of the most well-known diseases that rodents can transmit:

Hantavirus Pulmonary Syndrome (HPS):

Cause: Hantaviruses (from deer mice, white-footed mice, etc.)

How Transmitted:  Inhalation of dust contaminated with rodent droppings/urine

Symptoms: Fever, muscle aches, severe respiratory distress

Fatality Rate: Up to 38% untreated

Where Common: Rural settings such as barns and cabins

Leptospirosis:

Cause: Leptospira bacterium from urine

How Transmitted: Exposure to contaminated water/soil (i.e. floods)

Symptoms: Fever, jaundice, damage to kidneys/liver

More severe form: Weil’s disease

Rat-Bite Fever (RBF):

Cause: Streptobacillus moniliformis or Spirillum minus

How Transmitted: Rat bite or scratch or contaminated food or water

Symptoms: Fever, rash, joint pain, vomiting

Salmonellosis:

Cause: Salmonella bacteria from rodent feces

How Transmitted: Contaminated food and/or water

Symptoms: diarrhea, fever, abdominal cramps

Lymphocytic Choriomeningitis (LCM):

Cause: LCM virus from house mice

How Transmitted: Contact with droppings, urine or nesting materials

Symptoms: flu like (however it can develop in meningitis)

Risk: Pregnant women can be harmed (after symptoms present) to fetus