Nipah Virus Resurfaces in Kerala

Context

In July 2025, Kerala reported fresh cases of Nipah virus infection in Kozhikode, Malappuram, and Palakkad districts, with one confirmed fatality and two other confirmed cases under treatment. The National Institute of Virology (NIV), Pune, has validated the diagnosis, prompting the Kerala government to initiate strict containment measures and surveillance, with 345 individuals placed under observation.

What is Nipah Virus (NiV)?

Nipah virus is a zoonotic paramyxovirus from the genus Henipavirus, known to cause severe acute encephalitis and respiratory illnesses in humans.
First identified in Malaysia in 1998, with pigs as intermediate hosts. In India, outbreaks have been recorded in West Bengal (2001, 2007) and Kerala (2018, 2021, 2023, 2025).
The virus has a case fatality rate ranging from 40% to 75%, as per WHO estimates.

Modes of Transmission and Symptoms:

Transmission occurs via:
- Direct contact with infected bats, pigs, or humans
- Consumption of contaminated date palm sap or fruits
- Human-to-human transmission, especially among healthcare workers or caregivers
Symptoms: Fever, headache, drowsiness, confusion, seizures, and encephalitis. Respiratory distress is also common in some outbreaks.

Government Response and Preparedness:

Contact tracing and route mapping of infected individuals have been initiated in affected districts.
Quarantine of healthcare workers who treated confirmed cases and post-mortem teams has been implemented.
Kerala Health Department has placed Kozhikode, Palakkad, and Malappuram under enhanced surveillance and isolation protocols.
NiV is a Category A pathogen as per CDC, warranting BSL-4 (Biosafety Level-4) lab handling for research and diagnostics.