Nipah virus infection – India

On January 26, 2026, India informed the WHO about two confirmed Nipah virus cases in West Bengal. Initial testing suggested infection, confirmed via the National Institute of Virology, Pune, on January 13, 2026.

Both cases were verified through RT-PCR and ELISA tests.

The first case is a female nurse, while the second is a male nurse, both in their 20s to 30s from Barasat. They began to exhibit severe NiV symptoms in late December 2025 and were admitted to the hospital in early January 2026. As of January 21, the male patient was improving, but the female was still in critical condition.

After these confirmed cases, local health authorities traced and tested over 190 contacts, which included healthcare professionals and community members. All tested negative for NiV.

The Indian National Centre for Disease Control announced on January 27 that there haven’t been any further confirmed cases in West Bengal since December 2025.

NiV is a zoonotic disease transmitted from infected animals, particularly bats, to humans or through contaminated food. There’s also potential for person-to-person transmission via close contact. Fruit bats of the Pteropus species are natural hosts for the virus.

The incubation period typically ranges from 3 to 14 days, though rare instances have reported up to 45 days. Diagnosis can occur during the acute and recovery phases through a combination of tests like RT-PCR and ELISA.

Symptoms of NiV infection can vary widely, from asymptomatic to severe respiratory infection and potentially fatal encephalitis. Initial symptoms can include fever, headaches, muscle pain, vomiting, and sore throat, followed by neurological signs and possible severe complications.

More details about NiV infection can be found here.

The case fatality ratio across various outbreaks has varied from 40% to 75%, relying on local conditions for early detection and treatment. Currently, no treatments specifically for NiV are available. Supportive care remains crucial for those with severe symptoms.

Local authorities have implemented several public health measures, including:

• The Government of India has collaborated closely with the West Bengal government to initiate prompt public health measures following established protocols.
• Investigations have been carried out in a collaborative, One Health approach.
• Contact tracing around the identified cases is ongoing, with continuous follow-up.
• Surveillance has been strengthened to ensure early detection of additional cases.
• Health education and community engagement initiatives are underway.
• Healthcare professionals have been informed about NiV, with enhanced infection prevention measures in place at medical facilities.
• Sample collection, transportation, and testing were executed promptly.

WHO has provided support by:

• Assisting with national and international communication regarding the event, including IHR notifications.
• Monitoring the evolving situation, particularly during Nipah season, to understand epidemiological factors and spread.

Nipah virus poses a high case fatality rate (CFR) between 40-75% with no licensed vaccine or treatment available. The virus is primarily found in fruit bats, which are common across many regions, including India and Southeast Asia. While human transmission can occur through animals, secondary human-to-human transmission is also possible. Nipah was first spotted in 1998 and has since appeared in several countries, including India, where the outbreaks are often tied to bat activity and harvesting raw date palm sap.

This incident marks the 13th recorded Nipah outbreak in India and the third in West Bengal. Since 2001, there have been twelve Nipah outbreaks, predominantly in Kerala. Based on existing information, WHO assesses the public health risk of NiV at the sub-national level as moderate, largely due to the absence of specific treatments and challenges with early diagnosis. While laboratory methods exist, initial symptoms can be vague, hindering prompt identification and response. Additionally, fruit bats, the virus’s natural reservoir, are prevalent in India, heightening the risk of repeated outbreaks.

Human-to-human transmission has been witnessed before, particularly in healthcare settings and among caregivers through close contact. It’s crucial to enforce adequate infection control in medical facilities to prevent associated infections.

The number of reported cases in India has remained low overall since 2001, with notable spikes occurring in 2001 and 2018. In recent years, limited confirmed cases have emerged, all located in Kerala. India has robust public health measures for outbreak detection and management, including established surveillance and rapid response teams.

WHO assesses the regional public health risk from NiV to be low, given no cross-border transmission has been reported and the geographical extent of the outbreak is still contained. However, the underlying risk continues due to ecological ties between fruit bats and previously reported human cases. India’s historical expertise in managing certain outbreaks is significant.

Globally, the public health risk from NiV is rated low, as there’s been no evidence of spread beyond India.

Without a licensed vaccine or specific therapy for Nipah virus disease, prevention hinges on increasing awareness of risk factors. Guidance about reducing exposure and risk communication is vital. This is particularly true during mass gatherings, where attendees may be unfamiliar with the disease and its transmission. Management of cases should focus on timely supportive care, reinforced by effective laboratory systems and strong infection prevention measures in healthcare settings. Intensive supportive care is essential for serious respiratory and neurological complications.

Public health education should emphasize:

Minimizing bat-to-human transmission risks

• Efforts should focus on limiting bats’ access to date palm sap and other food. Freshly collected sap should be boiled, and fruits must be washed and peeled properly; any fruits showing bat bites should be discarded. Areas where bats roost should be avoided.

Reducing human-to-human transmission risks

• Avoiding close contact with NiV-infected individuals is crucial. Regular handwashing is necessary after visiting or caring for someone who is ill. Claimants displaying symptoms similar to Nipah should seek immediate medical attention, as early supportive care is key. Tracking and monitoring contacts can help curb human-to-human transmission.

Controlling infections in healthcare settings

• Healthcare workers must adhere to standard precautions when dealing with suspected or confirmed NiV cases and specimens.
• While treating these patients, WHO recommends using contact and droplet precautions, including wearing medical masks, protective eyewear, gowns, and gloves. Airborne precautions should be observed during procedures that generate aerosol, and suspected or confirmed cases should be isolated in dedicated rooms. Similar precautions apply for family members visiting these patients.
• Specimens from individuals suspected of having NiV infection must be handled by trained professionals in specialized laboratories.

Currently, WHO does not advise any travel or trade restrictions based on the information available.

• World Health Organization. Nipah virus [Fact sheet]. Geneva: WHO; 2026. Available from: https://www.who.int/news-room/fact-sheets/detail/nipah-virus
• Ministry of Health and Family Welfare. Only Two Nipah Virus Disease Cases Reported in West Bengal Since Last December: NCDC. 196 Contacts Linked to Nipah Cases Traced and Found Asymptomatic; All Test Negative.
• News On AIR. West Bengal reports two suspected Nipah cases; Centre sends response team. New Delhi: Prasar Bharati; 13 January 2026.
• News On AIR. Centre deploys National Joint Outbreak Response Team in West Bengal after suspected Nipah cases. New Delhi: Prasar Bharati; 12 January 2026.
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• World Health Organization, Regional Office for South-East Asia, Epidemiological Bulletin WHO Health Emergencies Programme, 2nd edition (2026), 28 January 2026.
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• World Health Organization. Standard precautions for the prevention and control of infections: aide memoire. Geneva: WHO; 2022.

Citable reference: World Health Organization (30 January 2026). Disease Outbreak News: Nipah virus infection in India.