Superspreading potential of Nipah virus disease despite self-limited human-to-human transmission in community

As of late January 2026, the World Health Organization (WHO) reported a small-scale Nipah virus (NiV) outbreak in West Bengal, India. Despite that NiV was primarily transmitted through animal sources, we assessed the transmission risks of NiV at human community level based on a total of 23 studies identified from literature of historical outbreaks that investigated human-to-human transmission of laboratory-confirmed NiV in Bangladesh and India. The data included transmission events containing 33 primary NiV cases and 152 secondary cases. We constructed a modelling framework for superspreading risk assessment, and found that 92.0% (95% CrI: 87.0, 95.4) of the NiV cases could not generate secondary cases via human-to-human transmission. With 5 seed cases imported to a community, there was a 1.1% (95% CrI: 0.3, 2.3) chance of observing an outbreak exceeding 50 NiV cases. Our findings may inform public health preparedness at community level and cross-border travel ban.