Why One Health Pays: Economic Evidence from Anthrax Outbreak Responses in Tanzania

Abstract

One Health (OH) is defined by the One Health High-Level Expert Panel as an integrated and unifying approach that aims to sustainably balance and optimise the health of people, animals, and ecosystems. Tanzania has made progress in adopting OH through strengthened institutional frameworks and coordination mechanisms; however, the approach remains underfunded and evidence on its economic value is limited. This study applied cost-benefit analysis (CBA) to evaluate the OH intervention implemented during the 2016 and 2019 anthrax outbreaks in the Selela and Nzoka regions of Tanzania. The analysis compared three scenarios: the actual coordinated OH response, a simulated uni-sectoral response, and a no-response scenario. Epidemiological, disease burden, and economic models were used to estimate infections, deaths, intervention costs, disease costs, and net benefits over a 5-year period, discounted at 5% annually. Data were drawn from surveillance systems, outbreak reports, laboratory records, cost documents, expert consultations, and a 2022 multisectoral stakeholder validation workshop. The analysis showed that the OH intervention generated clear economic gains. Outbreak-response costs were 32.5% lower, while total economic benefits were 18.7% higher compared to the uni-sectoral approaches. The primary drivers of these gains were averted human deaths, reduced livestock losses, lower treatment-related expenditures, and faster outbreak containment. The OH approach also enhanced the quality of data interpretation and improved operational efficiency and timeliness during the response. Overall, the CBA demonstrates that the OH intervention provides a more cost-effective and beneficial option for managing anthrax outbreaks in Tanzania. Strengthening national commitment to OH, including sustained domestic financing, improved preparedness, stronger subnational capacity, and enhanced data systems will be essential for maximising the economic value of future OH interventions. © The Authors 2026