The study aimed to determine costs to the state government of implementing different interventions for controlling rabies among the entire human and animal populations of Tamil Nadu. This built upon an earlier assessment of Tamil Nadu's efforts to control rabies. Anti-rabies vaccines were made available at all health facilities. Costs were estimated for five different combinations of animal and human interventions using an activity-based costing approach from the provider perspective. Disease and population data were sourced from the state surveillance data, human census and livestock census. Program costs were extrapolated from official documents. All capital costs were depreciated to estimate annualized costs. All costs were inflated to 2012 Rupees. Sensitivity analysis was conducted across all major cost centres to assess their relative impact on program costs. It was found that the annual costs of providing Anti-rabies vaccine alone and in combination with Immunoglobulins was $0.7 million (Rs 36 million) and $2.2 million (Rs 119 million), respectively. For animal sector interventions, the annualised costs of rolling out surgical sterilisation-immunization, injectable immunization and oral immunizations were estimated to be $ 44 million (Rs 2,350 million), $23 million (Rs 1,230 million) and $ 11 million (Rs 590 million), respectively. Dog bite incidence, health systems coverage and cost of rabies biologicals were found to be important drivers of costs for human interventions. For the animal sector interventions, the size of dog catching team, dog population and vaccine costs were found to be driving the costs. Rabies control in Tamil Nadu seems a costly proposition the way it is currently structured. Policy makers in Tamil Nadu and other similar settings should consider the long-term financial sustainability before embarking upon a state or nation-wide rabies control programme. Author Summary Rabies is a fatal viral disease. It is transmitted mostly through dog bites in greater parts of Asia and Africa. It is primarily a disease of the poorer population groups with children being the most vulnerable. Control of rabies among humans therefore requires interventions in the animal as well as the human sectors. Animal sector interventions include vaccination accompanied with or without sterilization of dogs. Human interventions are limited to individual vaccination following dog bites. We estimated the costs to the government of rolling out animal as well as human sector interventions across an entire state having a human population of 72 million. We also estimated the major drivers influencing program costs and the implications to the government of adopting such a strategy over a long time. We found that the animal sector interventions were many times more costly than the most expensive human interventions. We also found that in the absence of dog population control measures, it will require substantial financial commitment on the part of the government to be able to invest in dog vaccination strategies.
