Development and evaluation of methods to control rabies in Goa state, India

Rabies represents a tragic modern-day paradox; effective methods for its elimination have been available for a century, and yet thousands of children living in low resource settings die of the disease in abject suffering every year. Countries across Latin America eliminated the dog rabies virus through coordinated mass vaccination campaigns targeting the reservoir dog population, but large-scale control efforts have failed to progress in much of Africa and Asia. An estimated 20,000 people die of rabies each year in India, representing one third of the global total. Recent innovations in human medicine have improved access to life-saving post-exposure prophylaxis, however the close relationship between people and an ever-increasing dog population make a One Health approach axiomatic to rabies elimination. Without effective strategies to monitor and control the disease in dogs, the issue of dog transmitted rabies will continue ad infinitum. The work presented in this thesis explores operational approaches to rabies control in Goa State, India from 2013 to 2022 through a collaboration between Mission Rabies and the Government of Goa. A novel smartphone app developed during nascent campaigns formed the foundation of programme management and evaluation. The technology leveraged the enhanced data-capture and transmission capabilities of smartphones to improve the efficiency, efficacy, and political potency of mass dog vaccination campaigns in Goa and at project sites globally. Two-way data transfer between programme managers and the remote vaccination workforce within the platform revolutionised efficient spatial deployment of resource and aggregated the details of over 600,000 individual dog vaccination events in near-real time. Analysis of this high-resolution programmatic data garnered new insights into dog distribution, population composition, and parenteral vaccination accessibility across the urban-rural continuum that informed data-driven optimisation of the vaccination strategy. Concurrent advancement of state-level rabies surveillance systems enabled monitoring of the impact of vaccination and education activities. Human rabies deaths declined to zero and the dog rabies virus was eliminated from large areas of the state, with persistence in regions bordering endemic populations. Goa became the first state in India to become a ‘Rabies Controlled Area’ in 2021 and the programme was found to be ‘very cost-effective’ by WHO criteria for public health interventions. In recognising the operational and logistical constraints of existing mass dog vaccination methods, the potential incorporation of oral rabies vaccination of dogs was explored. A pilot study identified methods that could cost-effectively increase vaccination coverage in difficult to access dog populations, whilst also reducing human resource requirements. The results of a second study supported the use of baits made of an egg-based construct which met requirements of being widely palatable to dogs, culturally acceptable, and potentially mass producible. The findings of this thesis provide insights for advancing feasible and politically attractive solutions for the elimination of rabies at scale through the lens of One Health. Mobile technology, developed through field experience, drove a step-change in the spatial coordination of remote vaccination resource and data quality. Detailed understanding of reservoir population dynamics offers new opportunities for resource prioritisation and efficiency-savings through modelling of rabies transmission and intervention design. The iterative process of operational learning and refinement will need to continue as campaigns progress to new geographies and scales, however the work in Goa demonstrates that dog rabies control in many parts of India is within reach. By advancing approaches to mass dog vaccination, our generation has an opportunity to change the trajectory of a disease which inflicts profound suffering on people and animals already disadvantaged by circumstance.