India has the highest number of human deaths from rabies of any country [1, 17]. The administration of canine rabies vaccines to more than 70 % of dogs has been well documented in numerous countries to greatly reduce the incidence of rabies in both human and canine populations [13, 18–20]. Despite the pressing need for effective canine rabies vaccination programmes in India, there have been few publications describing canine rabies vaccination strategies in the country with the highest rabies burden [8, 9, 11]. Specifically, there is a paucity of publications which have demonstrated that a large number of dogs can be vaccinated in a short period of time at a high vaccination coverage. For example, a recent study in India reported the vaccination of an average of 47 dogs (range 22–69) in six Indian villages at a median vaccination coverage of 34 % . The authors highlighted the challenges of handling dogs and misconceptions regarding dog vaccination as barriers to achieving a higher vaccination coverage. Another study reported a vaccination coverage of 35.5 % although a larger number of dogs were vaccinated during this long term project . Consequently, our programme, which vaccinated over 6900 dogs in 94 days and achieved a mean vaccination coverage of over 70 % in 16 of the 18 wards robustly demonstrates, for the first time, that large number of free roaming dogs can be vaccinated at high coverage in India in a short period of time.
An important outcome of our study is not only that almost all wards had a mean vaccination coverage of over 70 %, but that the lowest confidence interval for vaccine coverage was over 70 % in nearly three quarters of all the wards. This demonstrates that for the vast majority of wards, we can be confident that high vaccine coverage was achieved. Furthermore, our approach demonstrated the value of examining vaccine coverage in smaller areas within large cities. For example, vaccine coverage across a large city may be over 70 % yet there might be large enough populations of dogs in areas of low vaccine coverage which could allow rabies to be maintained within the dog population. By examining coverage in numerous small wards throughout the city, we have been able to demonstrate that the lower vaccination coverage confidence value was never below 52 % and in 16 of the 18 wards was above 63 %.
In this study, the use of mobile technology and a tailor made smartphone app to provide specific functionalities of data entry and boundaries displayed on maps, enabled efficient and simple region wise direction of catching and survey teams. Although mobile phone technology has been used in other epidemiology studies , this is the first study to report the development and implementation of a bespoke app tailored towards the collection of data relevant in canine rabies field work. Data captured remotely in the field was tagged with GPS location and synchronized to a web based server. The project manager could then instantly view maps of where the vaccination teams had been working or download data in spreadsheet format for estimation of vaccination coverage enabling the prompt direction of teams back to areas with low coverage. This instant access to digitalised data saved significant management time in conversion of paper records into an electronic spreadsheet and therefore made the application of the system more appealing and sustainable at the project management level. The resulting dataset also facilitates study of dog demographics and spatial analysis. Designation of boundaries on Google maps enables a complex geographic area with poor existing mapping, defined regions or road names such as Ranchi to be systematically searched for the presence of dogs. This technology was crucial in allowing the field teams to vaccinate a high percentage of the dog population. Assessing the cost-benefit of using mobile technology over other paper records are outside of the scope of this study, however basic smart phones are becoming increasingly affordable and when factored into the overall budget for mass vaccination campaigns, the cost of using smart phones per dog vaccinated is minimal. The benefits in improved reporting, team direction, impact assessment and project management have been found to be invaluable in the authors’ experience managing multiple remote projects on a large scale.
Our study describes a vaccination programme which successfully addressed the dual challenges of vaccinating a large number of dogs at a high vaccination coverage in a relatively short period of time. There is often a culture of quasi-ownership in India whereby members of the community feed free roaming dogs, and therefore support their survival and reproduction, however, little responsibility is taken to ensure that the dog can be handled or that rabies vaccination or sterilization occurs. This produces a profound public health and animal welfare risk and means that accessing 70 % of the free roaming dog population for vaccination is more challenging. A major challenge in Ranchi, which is typical of many India cities, was the high proportion of dogs which were free roaming (92 %). Unlike in Africa, where a large number of dogs are owned and can be vaccinated through static point vaccine approaches [13, 18, 23], the vast majority of dogs in Ranchi were not identifiably owned. In this study teams used butterfly nets to catch and restrain the large number of dogs which were not amenable to handling. The use of butterfly nets has been previously described in vaccination campaigns in Bali where the majority of dogs were not amenable to handling [7, 24] and has been found to be more effective and humane than other capture methods in this situation, however the approach and methods must be tailored to each local setting. Minimising the detrimental impact on the welfare of each animal treated whilst achieving the greatest possible benefit to the wider human and animal populations through rabies control need to be carefully balanced and continuously reviewed and refined.
The approach of assessing vaccination coverage by recording the number of marked, vaccinated and unmarked, unvaccinated dogs has been widely reported. This simple method of marking vaccinated dogs followed by dog-sight surveys to estimate vaccination coverage in the abundant free roaming dog populations is a cheap and effective system to estimate vaccination coverage in real-time. Mass vaccination campaigns provide an ideal opportunity for gathering information about a large cross section of the population with minimal additional effort which can then be used to better direct resources and refine effective methods [10, 25]. Measurement of demographic data such as body condition score, skin condition and reproductive status enables monitoring of change in the population over sequential vaccination campaigns and assessment of the impact of other interventions such as sterilization and education activities. The sex distribution observed in this study is comparable to previous reports on Indian dog demographics [26–28].
The problem of dogs in India is often perceived to be one of “too many dogs on the street” as opposed to rabies being the prime problem, with the latter being a far easier issue to address in the short term if handled in isolation. The problem of free roaming dog over population is more complex, with cultural and ecological root causes which take longer to influence than dog vaccination alone. Long-term, sustained CNVR programmes in Rajasthan have successfully eliminated rabies as well as reducing dog population turnover, therefore enhancing persistence of vaccinated animals in the community [15, 21, 29]. A study in Jaipur reported sterilization of 66 % of the female dog population resulted in a 28 % reduction in roaming dogs over the eight year period of work . In this study 78 % of the roaming dog population was estimated to be sterilize, which is likely to have resulted in a similar reduction in population turnover. Given the sheer size of the dog population in many Indian cities, it is unlikely to be cost-effective, logistically feasible or ecologically beneficial to conduct blanket CNVR interventions with the aim of controlling rabies nationally. Instead dog population management may be viewed as a separate undertaking which is based on targeting dogs most likely to contribute to the problem on a location-by-location basis. VMR does not require the same level of veterinary expertise, infrastructure, equipment and consumable costs that are needed in CNVR which also requires additional investment in monitoring and quality control to ensure animal welfare is upheld to the highest possible standards. Therefore, more emphasis should be placed on mass dog vaccination in order to reduce the incidence of rabies over a large area in the shorter term . Further study is needed to assess the cost effectiveness of mass canine vaccination initiatives such as the one developed in this study.