IEDCR warns Nipah no longer seasonal threat

Staff Reporter :

The spread pattern of the Nipah virus in Bangladesh is changing, with health authorities warning that the country has recorded its first off-season infection and that transmission may now be occurring beyond the traditional winter-linked pathways. The Institute of Epidemiology, Disease Control and Research (IEDCR) said this shift signals a more persistent, year-round public health risk.

At a programme held in Dhaka on Wednesday, health officials said Nipah should no longer be viewed as a disease limited to winter months or linked solely to raw date palm sap, which has historically been the main source of outbreaks. New evidence suggests the virus may now spread through multiple routes across different seasons.

Presenting surveillance data, IEDCR scientific officer Sharmin Sultana said all four Nipah cases reported in 2025 resulted in deaths, marking a 100 percent fatality rate for the year. The infections were identified in Naogaon, Bhola, Rajbari and Nilphamari districts.

One case involved an eight-year-old child from Naogaon who became infected in August-well outside the usual winter period when Nipah cases are typically detected. Officials said the child had eaten fruits such as black plum, dates and mangoes that were partially consumed by bats, describing this as a new and alarming mode of transmission.

According to IEDCR data, since the virus was first identified in Bangladesh in 2001, Nipah infections have been detected in 35 of the country’s 64 districts. Faridpur, Rajbari, Naogaon and Lalmonirhat have reported relatively higher numbers of infections and deaths.

Health officials noted that while the global fatality rate for Nipah is estimated at around 72 percent, Bangladesh has often experienced significantly higher mortality. The briefing also highlighted the risk of person-to-person transmission, stating that approximately 28 percent of cases worldwide occur through direct contact, posing serious risks to family members and healthcare workers.

Chairing the meeting, IEDCR Director Prof Dr Tahmina Shirin described the off-season case and emerging transmission routes as a “serious warning” for the country.

“Nipah is no longer limited to winter or date palm sap. It is evolving into a year-round disease with multiple transmission pathways,” she said.

Nipah virus surveillance coordinator Dr Syed Moinuddin Sattar said monitoring efforts have been intensified in high-risk districts and hospitals have been advised to remain on alert.

Health experts attending the event said the emergence of off-season cases and new infection routes highlights the urgent need for increased vigilance, stronger surveillance and wider public awareness to prevent future outbreaks.