An outbreak of the deadly Nipah virus in India’s West Bengal state has prompted heightened health surveillance in several parts of Asia, with countries moving swiftly to tighten screening measures at airports and border crossings.
Thailand has begun screening passengers at three international airports that receive flights from West Bengal, while Nepal has introduced health checks for arrivals at Kathmandu’s airport and at key land border points with India.
India’s health ministry has confirmed two Nipah virus cases in West Bengal since December, reportedly involving healthcare workers. Authorities say 196 people who came into contact with the infected individuals have been identified, traced, monitored and tested, with all returning negative results.
The Nipah virus is a zoonotic disease that can spread from animals to humans, and also through person-to-person contact or contaminated food. Fruit bats and pigs are known carriers. The virus has a high fatality rate, estimated at between 40% and 75%, and there is currently no approved vaccine or antiviral treatment.
The World Health Organization has listed Nipah among its top ten priority diseases due to its epidemic potential, alongside pathogens such as Covid-19 and Zika. The incubation period typically ranges from four to 14 days, with symptoms varying widely.
Early signs of infection may include fever, headaches, muscle pain, vomiting and a sore throat. In more severe cases, patients may develop drowsiness, altered consciousness, pneumonia and encephalitis a potentially fatal inflammation of the brain.
While no cases have been reported outside India, several countries are stepping up preventative measures. Thailand has introduced health declaration requirements for passengers arriving from affected areas and has tightened screening at popular natural and wildlife tourist attractions. Nepal has similarly increased vigilance at entry points from India.
Taiwan’s health authorities have proposed classifying Nipah as a “Category 5 disease”, a designation reserved for emerging or rare infections posing major public health risks and requiring immediate reporting and special control measures.
Nipah was first identified in 1998 during an outbreak among pig farmers in Malaysia, which later spread to Singapore. More than 100 people died and around a million pigs were culled to contain the virus, causing major economic losses. Since 2001, Bangladesh has recorded more than 100 Nipah-related deaths, while India has experienced outbreaks in West Bengal and Kerala, with several fatalities reported in recent years.
India’s health ministry says the current situation remains under constant monitoring and that all necessary public health measures are in place.