Nipah Virus Remains a Serious Public Health Threat as India Reports New Cases

The cases were initially identified as suspected Nipah virus infections on 11 January by the Viral Research and Diagnostic Laboratory at a government hospital in Kalyani. Confirmation was subsequently provided by the National Institute for Virology in Pune on 13 January.

As of 21 January, the male patient is recovering, while the female patient remains in critical condition.

Containment and Public Health Response

Following confirmation, an extensive public health response was activated. A total of 196 individuals who had contact with the confirmed cases were identified, traced, monitored, and tested. All contacts have remained asymptomatic and have tested negative for Nipah virus infection.

As of 27 January 2026, no additional cases have been detected.

The national government has deployed an outbreak response team to West Bengal to work closely with state authorities. Enhanced surveillance, laboratory testing, infection prevention and control measures, and field investigations are underway. These coordinated efforts between central and state health authorities have enabled timely containment of the outbreak.

Targeted risk communication activities are also ongoing in affected and neighboring districts, with a focus on preventive behaviors such as avoiding the consumption of raw date palm sap.

Risk Assessment

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 assesses the risk at the sub-national level in West Bengal as moderate, given the presence of fruit bat reservoirs in the India–Bangladesh border areas and the possibility of sporadic zoonotic spillover. However, the national, regional, and global risk remains low.

The cases are confined to North 24 Parganas district, with no reported travel while symptomatic. All identified contacts have tested negative, and surveillance and infection prevention measures have been intensified. The likelihood of spread to other Indian states or internationally is considered low.

Historically, Nipah outbreaks in the WHO South-East Asia Region have been limited to Bangladesh and India, occurring sporadically or in small clusters. Human-to-human transmission is rare and usually confined to health-care settings or close family contacts. There have been no known instances of international spread through travel.

Based on current evidence, WHO does not recommend any travel or trade restrictions.

Nipah outbreaks in India

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

Nipah virus is primarily transmitted from bats to humans, either directly or through contaminated food. It can also spread from animals such as pigs to humans, and in some cases between people through close and prolonged contact, particularly in health-care settings.

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

WHO Recommendations and Community Guidance

Currently, there is no licensed vaccine or specific treatment for Nipah virus infection, although several candidates are under development. Early supportive care, including intensive care for severe respiratory or neurological complications, remains critical for improving survival.

WHO emphasizes the importance of infection prevention and control in health-care settings and community awareness to reduce exposure risks. Key public health messages include:

• Reducing bat-to-human transmission by preventing bats from accessing date palm sap, boiling freshly collected sap, washing and peeling fruits thoroughly, discarding fruits with signs of bat bites, and avoiding areas where bats roost.

• Reducing animal-to-human transmission by wearing protective clothing and gloves when handling sick animals or during slaughtering and culling.

• Reducing human-to-human transmission by avoiding unprotected close contact with infected individuals and practicing regular hand hygiene.

• Strengthening infection control in health-care settings, including adequate ventilation, risk assessment, and the use of appropriate personal protective equipment when caring for suspected or confirmed cases.

WHO continues to work closely with national and state health authorities in India to support risk assessment, surveillance, and outbreak response efforts.