Nipah virus (NiV)

Source:  NDTV

Context: Kerala has launched a serological survey to investigate the recurring outbreaks of Nipah virus (NiV), especially in high-risk zones of northern Kerala, where the virus has reappeared for the eighth time in eight years.

About Nipah virus (NiV):

• What is Nipah Virus?

• • Nipah is a zoonotic virus that spreads from animals (mainly bats) to humans.
  • It causes illnesses ranging from mild respiratory issues to fatal encephalitis.
  • The case fatality rate ranges from 40% to 75%, varying by region and healthcare response.

• Past Outbreaks:

• • First detected in Malaysia (1999) among pig farmers.
  • Bangladesh reported annual outbreaks since 2001.
  • India has seen outbreaks in West Bengal (Siliguri) and Kerala, where eight episodes have occurred since 2018.

• Natural Host & Vector:

• • Fruit bats of the Pteropodidae family (genus Pteropus) are the natural reservoirs.
  • Infected bats can transmit the virus through saliva, urine, or feces on fruits or nearby surfaces.

• Transmission Pathways:

• • Animal to Human:
    • Through direct contact with infected pigs or bats.
    • Via contaminated food or fruit juices, e.g., raw date palm sap.
  • Human to Human:
    • Close contact with infected individuals’ bodily fluids.
    • Common in healthcare settings, especially among caregivers and hospital workers.

• Clinical Symptoms:

• • Early symptoms: Fever, sore throat, headache, myalgia, vomiting.
  • Severe cases: Encephalitis, seizures, altered consciousness, respiratory distress.
  • Incubation period: Typically, 4–14 days, but can extend up to 45 days.
  • Long-term effects: 20% of survivors may suffer neurological issues such as personality changes or seizures.

• Diagnosis Methods:

• • RT-PCR: Detects virus RNA in bodily fluids.
  • ELISA: Detects NiV-specific antibodies.
  • Virus isolation and PCR assays used in advanced labs.

• Kerala’s New Serological Survey:
  • Uses pseudo virus neutralisation assays to detect antibodies.

• • Targets high-risk populations (humans + domestic animals) near known Nipah hotspots.
  • Aims to understand spillover dynamics, animal reservoirs, and transmission chains.