Zoonotic influenza poses a persistent threat to public health, agriculture, and ecosystems in the WHO South-East Asia Region. In response, the Infectious Hazard Management (IHM) unit, in technical collaboration with the University of Queensland and with support from the WHO Country Office for Nepal, piloted an innovative spatial risk assessment tool in Nepal—the Zoonotic Influenza Distribution and Ranking (ZIDAR) system—to strengthen cross-sectoral, risk-based surveillance and bolster pandemic preparedness.
The ZIDAR framework was designed using a comprehensive One Health approach, incorporating local expertise from human, animal, and environmental sectors. The framework identifies high-risk transmission “interfaces” where humans, livestock, and wildlife intersect, and ranks them based on expert input and spatial data analysis. It combines scientific modeling with expert prioritization to map zones where zoonotic influenza is most likely to emerge.
ZIDAR-H suitability map
In Nepal, ZIDAR was implemented through an expert-led process and validated using historical outbreak data. The resulting model revealed several hotspot zones—especially in the Kathmandu Valley, Pokhara, Bharatpur, and southern border regions—where high human and animal densities converge with habitat fragmentation and migratory bird flyways. These insights offer valuable guidance for targeting surveillance and preventive interventions.
Using R-based modeling and an interactive web application, the ZIDAR system allows policymakers to explore transmission risk across 18 identified interfaces, from live bird markets and low-biosecurity farms to migratory flyways and backyard poultry systems. The tool’s strong predictive performance (AUC scores of 0.87 and 0.85 for wildlife and animal interfaces, respectively) underscores its reliability in decision-making.
Notably, ZIDAR’s participatory design ensures trust and sustainability by empowering national surveillance teams in co-development and refinement of the model. As a decision support system (DSS), it represents a significant advancement in localizing One Health action against zoonotic threats.
ZIDAR enables evidence-based prioritization of disease surveillance and control efforts, supporting early warning systems, targeted vaccination, and cross-border biosecurity coordination. Its granular risk maps offer actionable intelligence for both national programmes and local-level response planning—critical for pandemic preparedness.
This initiative exemplifies the IHM Unit’s commitment to operationalizing the High Threat Pathogen (HTP) framework by translating complex risk landscapes into actionable surveillance priorities. It supports the IHM unit’s core goal of strengthening early warning systems through locally adapted, One Health-based decision support tools.
ZIDAR end-user elicitation process
Photos credit: WHO SEARO, WCO Nepal and Queensland Alliance for One Health Sciences, School of Veterinary Sciences, The University of Queensland
Reference:
Charette-Castonguay A, Gautam D, Shrestha B, Ojha HC, Sharma BK, Upadhayaya M, Rana S, Shrestha R, Chaudhary LB, Kandel B, Marasini RP, Chapagain S, Gompo TR, Karki S, Poudel A, Shrestha S, Kayastha AS, Govindakarnavar AK, Samuel R, Gocotano A, Ranjan Wijesinghe P, Buddha N, Salvador EC, Kakkar M, Magalhães RJS. Development of a zoonotic influenza distribution assessment and ranking system (ZIDAR): technical application in Nepal to support cross-sectoral risk-based surveillance. One Health. 2025; 20(4):100975. DOI:10.1016/j.onehlt.2025.100975.
Full text publication is available at: https://www.sciencedirect.com/science/article/pii/S2352771425000114