India media report two cases of human Nipah virus infection in West Bengal, in eastern India.
The patients are nurses and have been admitted to a Kolkata hospital. "The health condition of both of them remains extremely critical. They are still in a coma and admitted to the ICCU," according to an official of the health department.
According to State health department sources, one of the nurses recently returned from her hometown in Katwa in Purba Bardhaman district, where she fell ill and was initially admitted to a local hospital on December 31, 2025.
Following the emergence of the cases, 90 people, who were in close contact with the patients, have been traced and are under observation.
Nipah virus (NiV) is an emerging and serious viral zoonotic disease that carries with it a high case fatality rate (in the ballpark of 70% or more).
NiV is an enveloped RNA virus and along with Hendra virus make up the Henipahviruses.
The natural host of the virus are fruit bats of the Pteropodidae family, Pteropus genus.
It was first recognized in a large outbreak in Kampung Sungai Nipah, Malaysia and Singapore from Sep 1998 – May 1999.
276 cases were reported, the vast majority (93%) being pig farmers or people who had contact with pigs. The disease presented as encephalitis and four out 10 people died.
It is theorized that the pigs got infected consuming partially bat-eaten fruit that ended up in a pigsty. Pigs were the intermediate host in this case; however, subsequent outbreaks had no intermediate hosts.
No new outbreaks have been reported in Malaysia since 1999.
The outbreaks since the initial one in Malaysia (Bangladesh and India) have been linked to two possible routes of transmission—consumption of raw date palm sap that had been contaminated with urine or saliva from infected fruit bats and strong evidence points to human-to-human transmission (close physical contact, especially contact with body fluids).