Nipah

Nipah virus (NiV) is a zoonotic RNA virus in the genus Henipavirus, family Paramyxoviridae. It is associated with severe disease in humans and animals and was first identified during a 1998–1999 outbreak among pig farmers in Malaysia and Singapore, where pigs acted as amplifying hosts.

Fruit bats of the genus Pteropus are the natural reservoir for NiV. Spillover to humans occurs through contact with infected animals, especially pigs, or through exposure to bat-contaminated fruit or products. Human-to-human transmission has been documented, particularly in caregiving and hospital settings, leading to clustered outbreaks in Bangladesh and parts of India.

The incubation period for Nipah virus infection is typically 4 to 14 days. The clinical spectrum ranges from asymptomatic infection to severe illness, including acute febrile encephalitis and respiratory disease. Neurological symptoms can include drowsiness, confusion, seizures, and coma; respiratory symptoms may also be prominent. Case fatality rates have varied by outbreak and setting, commonly reported from about 40% to 75%.

Diagnosis relies on molecular methods such as RT-PCR to detect NiV RNA in respiratory or cerebrospinal fluid samples, complemented by serology. There is no licensed vaccine or antiviral treatment proven effective for humans; management is supportive, with infection control measures to prevent transmission.

Prevention focuses on reducing bat-to-human spillover, minimizing exposure in livestock settings, and rigorous infection prevention in healthcare facilities. Surveillance, rapid case identification, and public health response are essential during outbreaks. Research into vaccines and therapies is ongoing, with several candidates in development but no widely available human vaccine as of now.