WHO confirms two Nipah infections in West Bengal - risk low beyond region

Two laboratory-confirmed Nipah virus infections among healthcare workers in Barasat, West Bengal, have prompted a focused containment response, the World Health Organization said, while characterizing the risk of spread beyond the affected subnational area as low.

WHO’s Disease Outbreak News, published on January 30, reports that both confirmed cases are staff at the same private hospital in North 24 Parganas district. The National Institute of Virology in Pune confirmed infection by RT-PCR and ELISA on January 13, and deployed a mobile BSL-3 laboratory to support field testing. India’s National IHR Focal Point notified WHO on January 26.

Clinical details released by Indian authorities and relayed by WHO show one patient remained on mechanical ventilation as of January 21, while the other had experienced severe neurological illness and subsequently improved. Authorities have not identified further confirmed cases to date, according to WHO.

Public-health teams carried out intensive contact tracing. The Indian Ministry of Health and Family Welfare and the National Centre for Disease Control reported that 196 contacts were traced, found asymptomatic and tested negative. WHO summarized that more than 190 contacts had been tested with negative results. These official counts contrast with some media reporting. The BBC cited local sources saying at least five cases had been reported earlier in January and that about 110 people had been quarantined; those figures differ from the national notification to WHO.

The response in India included deployment of a National Joint Outbreak Response Team and support from the NIV mobile laboratory, underlining the role of rapid laboratory capacity in limiting spread. Internationally, neighboring countries and agencies moved to precautionary measures: Thailand began screening passengers arriving from West Bengal at major airports and asked travelers to complete health declarations; Nepal intensified screening at Kathmandu airport and land border points. The European Centre for Disease Prevention and Control assessed the risk to Europeans as very low and reiterated ordinary food-safety precautions for fruit and vegetables.

Experts warn that Nipah presents particular risks in health-care settings. Al Jazeera reported that a source identified only as Abbas suggested the two confirmed cases being health workers “indicates a potential transmission from an infected but undiagnosed patient to the healthcare workers at the hospital.” Historical outbreaks show the pattern of nosocomial amplification: West Bengal’s earlier clusters in 2001 and 2007 and repeated outbreaks in Kerala have involved transmission in hospitals and high mortality in some waves. The virus is zoonotic, maintained in fruit bats, and can infect humans via contaminated food, direct animal contact or person-to-person spread, according to ECDC and WHO background material.

The human toll is immediate and personal. Local reporting cited one nurse as in “very critical” condition, reflecting the stakes for frontline workers and their families. Jurai Wongswasdi, a spokeswoman for Thailand’s Department for Disease Control, told BBC officials there were “fairly confident” measures in place to guard against an outbreak in Thailand.

The current containment indicators - confirmed laboratory diagnosis, rapid deployment of field testing and comprehensive contact testing with no confirmed secondary cases - suggest the event has been limited in scope so far. But the pattern highlights persistent systemic weaknesses: occupational safety in under-resourced hospitals, gaps in early detection of atypical febrile or neurological illness, and the cross-border social and economic impacts of precautionary screening. Ensuring transparent, timely reporting and protecting healthcare workers remain essential to preventing small clusters from widening into larger outbreaks.