After global airport alerts, WHO says Nipah spread risk from India is low

India reported the infections in North 24 Parganas district of West Bengal. According to WHO, there is currently no evidence of increased human-to-human transmission.

“India has demonstrated its capacity to manage Nipah outbreaks during previous events, and recommended public health measures are being implemented jointly by national and state health teams. At this time, there is no evidence of increased human-to-human transmission,” WHO said in a statement.

The two cases are confined to North 24 Parganas district, and neither patient had travelled while symptomatic. All identified contacts have tested negative so far, and surveillance and infection prevention measures have been intensified.

“The likelihood of spread to other Indian states or internationally is considered low,” the statement added.

WHO further noted that historically, Nipah outbreaks in the South-East Asia Region have been limited to Bangladesh and India, typically occurring sporadically or in small clusters. Based on current evidence, the global health body does not recommend any travel or trade restrictions.

Details of the Latest Cases

The two infected individuals are 25-year-old nurses — a man and a woman — working at the same private hospital in Barasat, located in North 24 Parganas district.

They developed initial symptoms in the last week of December 2025, which rapidly progressed to neurological complications. Both were placed in isolation in early January.

The suspected cases were first identified on January 11 by the Viral Research and Diagnostic Laboratory at a government hospital in Kalyani. Confirmation was provided by the National Institute of Virology (NIV), Pune, on January 13.

Following confirmation, several countries — including Hong Kong, Malaysia, Singapore, Thailand, and Vietnam — initiated enhanced airport screening measures as a precautionary step.

So far, no additional cases have been reported from West Bengal.

What Is Nipah Virus?

Nipah virus is a zoonotic disease, meaning it is transmitted from animals to humans. Fruit bats are the primary natural reservoir. Transmission can occur through direct contact with infected bats, consumption of contaminated food, or exposure to infected animals such as pigs. In some cases, the virus can spread between humans through close and prolonged contact, particularly in healthcare settings.

In humans, infection can range from mild or asymptomatic illness to severe respiratory disease and fatal encephalitis (inflammation of the brain). Globally, the case fatality rate is estimated to range between 40% and 75%, depending on early detection and the quality of clinical care.

Currently, there is no licensed vaccine or specific antiviral treatment for Nipah virus. Early diagnosis, supportive medical care, and strict infection prevention measures remain the primary tools to control outbreaks.

This marks the seventh documented Nipah outbreak in India and the third in West Bengal, following previous outbreaks in Siliguri (2001) and Nadia (2007). The affected districts share a border with Bangladesh, where Nipah outbreaks occur almost annually.