A cost-outcome assessment of dog deworming for echinococcosis control in the Xizang Autonomous Region, China, 2016–2022

Background: Xizang is the most endemic region of echinococcosis in China. Dog deworming is the most important measure in Central Government’s Transfer Payment Project for Echinococcosis Control. Yet the economic performance of dog deworming across diverse settings in Xizang has not been systematically assessed. To address this gap, we examined the cost of dog deworming and assessed its outcome at county-level in the Xizang Autonomous Region (Xizang). Methods: We collected data on dog management and deworming from 74 counties in Xizang from 2016 to 2022. Canine infection rate was used as the key indicator to assess the outcome of dog deworming. Statistical analyses were conducted to examine temporal changes in canine infection rate and related indicators, while spatial analyses were performed to compare county-level differences in cost, outcome, and cost-outcome. County-level cost-outcome analysis was further conducted to evaluate the cost required for every percentage-point reduction in the canine infection rate. Results: The canine infection rate showed a 91.1% reduction, from 5.63% in 2016 to 0.50% in 2022. The outcome of dog deworming displayed significant spatial variation. Canine infection rate decreased in 67 of 74 counties, and the reduction magnitude exceeded 80% in 46 counties. However, 7 counties showed a slight increase. Considerable regional heterogeneity in cost-outcome was observed: 44 of 74 counties required less than 50,000 CNY for each percentage point reduction in canine infection rate, including 19 counties below 10,000 CNY, whereas 6 counties exceeded 200,000 CNY per percentage point reduction. Conclusion: Dog deworming, as part of a sustained integrated control program, was associated with substantial reductions in canine Echinococcus infection in Xizang and showed favorable programmatic cost-outcome performance. As a major and key control measure, dog deworming should be sustained and consistently implemented. Particular attention should be paid to counties where the effect was not obvious or where infection rate increased, and the underlying reasons should be investigated to ensure that dog deworming is fully implemented. In addition, dog registration and tethering, stray dog sheltering, and proper disposal of canine feces should be further strengthened to improve the efficiency of source-control measures. Author summary: Echinococcosis, also known as hydatidosis, is a serious parasitic infection that affects both animals and humans. In China, Xizang has the highest burden of the disease. Dogs play a key role in spreading echinococcosis, and regular dog deworming is a critical measure to break the transmission chain. In this study, we analyzed data from 74 counties in Xizang from 2016 to 2022 to understand how well dog deworming programs work and to evaluate their cost-outcome performance. We found that canine infection rate has fallen sharply over the years, showing clear progress in echinococcosis control. However, cost, outcome, and cost-outcome varied across counties. While many counties achieved favorable results, some areas had high cost but relatively limited improvement. These findings show that dog deworming, as part of an integrated control program, was associated with reductions in canine Echinococcus infection in Xizang. This study provides practical evidence for improving the implementation efficiency of dog deworming in Xizang and may also offer useful reference for other endemic areas.