The Institute of Epidemiology, Disease Control & Research (IEDCR) has warned that Nipah virus infections have been detected in 35 districts across the country, with the pattern of spread and transmission changing at an alarming rate. The agency said that all four cases recorded last year (2025) resulted in death—a 100 percent fatality rate—and that, for the first time, an “off-season case” has also been identified.

The information was shared by IEDCR Senior Scientific Officer (SSO) Sharmin Sultana in a paper presented at a meeting regarding the spread and risks of Nipah virus held at the IEDCR auditorium on Wednesday (January 7). The meeting was chaired by IEDCR Director Professor Dr. Tahmina Shirin.

According to the presentation, four Nipah cases were identified in 2025 in Naogaon, Bhola, Rajbari, and Nilphamari districts, and all of the patients died. Among them, the case of an eight-year-old child from Naogaon was the country’s first recorded off-season Nipah infection, detected in August, outside the usual winter period. The source of infection was traced to the consumption of fruits partially eaten by bats—such as jamun (black plum), date palm fruit, and mango—marking a new and alarming transmission route.

The paper noted that Nipah virus has now been detected in 35 of Bangladesh’s 64 districts. Faridpur, Rajbari, Naogaon, and Lalmonirhat have reported comparatively higher infection and death rates. All four cases identified last year were fatal, resulting in a 100 percent mortality rate, while the global average fatality rate of Nipah virus is around 72 percent.

It further stated that although raw date palm sap has historically been considered the primary source of Nipah transmission, the Naogaon case in 2025 demonstrates that infection can also occur year-round through the direct consumption of any fruit contaminated by bat saliva or urine. The presentation also highlighted human-to-human transmission, noting that in about 28 percent of cases, the virus spreads directly from an infected person to others, posing a high risk to healthcare workers and family members.