Why in news?
Kerala announced a serological survey in July 2025 to identify people who have been exposed to Nipah virus in high‑risk districts. The state has experienced repeated outbreaks of this deadly zoonotic disease since 2018.
What is Nipah virus?
- Nipah virus (NiV) is a member of the Henipavirus genus, first recognised during a 1998–99 outbreak among pig farmers in Malaysia. Fruit bats (flying foxes) are its natural reservoir.
- The virus spreads to humans through contact with infected bats, pigs or contaminated food (e.g., date palm sap), and then through respiratory droplets or bodily fluids between people.
- Symptoms include fever, headache, respiratory distress, encephalitis and seizures. The case fatality rate ranges from 40 percent to 75 percent, depending on outbreak and healthcare quality.
- There is no approved vaccine or specific antiviral treatment. Care is supportive—managing fever, hydration and breathing until the immune system clears the virus.
Nipah outbreaks in India
- 2001: The first Indian outbreak occurred in Siliguri, West Bengal, with over 60 deaths. Transmission likely involved healthcare settings.
- 2018: Kerala’s Kozhikode district reported a cluster of cases with high mortality. Quick containment measures limited spread.
- 2021–2024: Sporadic cases resurfaced in Kerala’s Malappuram and Kozhikode districts. Investigations traced the virus to fruit bats living near villages.
Kerala’s 2025 serological survey
- Objective: Identify individuals who have developed antibodies to NiV, indicating past exposure. This information helps estimate how widely the virus has circulated and whether asymptomatic infections occur.
- Method: Blood samples will be collected from residents in high‑risk zones. ELISA tests detect IgG antibodies specific to NiV. Data will be anonymised to protect privacy.
- Implications: A better understanding of immunity will guide public‑health strategies, such as targeted awareness campaigns, early‑warning systems and research on potential vaccines.
Prevention strategies
- Avoid consumption of fruits or raw palm sap contaminated by bats.
- Strengthen surveillance of bat populations and pig farms.
- Isolate and monitor contacts of suspected cases promptly.
- Educate communities about personal hygiene and safe caregiving practices.