Nipah Virus Cases in West Bengal Prompt Heightened Vigil Across Asia

The detection of Nipah virus infections in India’s West Bengal has triggered precautionary measures in parts of Asia, with several countries tightening health screening protocols at airports and border points.

India has confirmed two cases of the highly lethal virus in West Bengal since December, both reportedly involving healthcare workers. According to the Union health ministry, 196 individuals who came into contact with the infected persons have been identified, monitored and tested, with all found to be negative and asymptomatic, BBC reported.

In response, Thailand has begun screening passengers arriving from West Bengal at three international airports, including facilities in Bangkok and Phuket. Travellers on these flights are being required to submit health declarations. Thailand’s parks and wildlife department has also stepped up health checks at natural tourist destinations. Officials said the country is confident about preventing any potential outbreak.

Nepal has similarly initiated screening of passengers arriving at Kathmandu airport and at several land border crossings with India. Taiwan, meanwhile, has proposed classifying the Nipah virus as a “Category 5 disease”, a designation reserved for emerging or rare infections that pose significant public health risks and require immediate reporting and special control measures.

What Is Nipah Virus?

Nipah virus is a zoonotic disease that can spread from animals such as fruit bats and pigs to humans, and can also be transmitted through contaminated food or via close human-to-human contact. It carries a high fatality rate, estimated between 40 per cent and 75 per cent, and currently has no approved vaccine or specific treatment.

The World Health Organization has listed Nipah among its top 10 priority diseases, alongside pathogens such as Covid-19 and Zika, due to its epidemic potential. The virus has an incubation period of four to 14 days, and symptoms can range from mild or asymptomatic infection to severe illness.

Early signs typically include fever, headache, muscle pain, vomiting and sore throat. In more serious cases, patients may develop drowsiness, altered consciousness, pneumonia and encephalitis, an inflammation of the brain that can be fatal.

The first known Nipah outbreak occurred in 1998 among pig farmers in Malaysia, later spreading to Singapore. More than 100 people died, and around a million pigs were culled to contain the virus, causing major economic losses. Bangladesh has recorded over 100 Nipah-related deaths since 2001.

India has experienced previous outbreaks in West Bengal in 2001 and 2007, while Kerala has emerged as a recent hotspot. In 2018, 17 of 19 confirmed cases in Kerala were fatal, and in 2023, two deaths were reported among six confirmed cases.

India’s health ministry said the situation in West Bengal is under continuous surveillance and that all necessary public health measures have been put in place. No cases have been reported outside India so far, but regional authorities remain on alert.