Oral bait handout as a method to access roaming dogs for rabies vaccination in Goa, India: A proof of principle study

Abstract

Rabies has profound public health, social and economic impacts on developing countries, with an estimated 59,000 annual human rabies deaths globally. Mass dog vaccination is effective at eliminating the disease but remains challenging to achieve in India due to the high proportion of roaming dogs that cannot be readily handled for parenteral vaccination. Two methods for the vaccination of dogs that could not be handled for injection were compared in Goa, India; the oral bait handout (OBH) method, where teams of two travelled by scooter offering dogs an empty oral bait construct, and the catch-vaccinate-release (CVR) method, where teams of seven travel by supply vehicle and use nets to catch dogs for parenteral vaccination. Both groups parenterally vaccinated any dogs that could be held for vaccination. The OBH method was more efficient on human resources, accessing 35 dogs per person per day, compared to 9 dogs per person per day through CVR. OBH accessed 80% of sighted dogs, compared to 63% by CVR teams, with OBH accessing a significantly higher proportion of inaccessible dogs in all land types. All staff reported that they believed OBH would be more successful in accessing dogs for vaccination. Fixed operational team cost of CVR was four times higher than OBH, at 127 USD per day, compared to 34 USD per day. Mean per dog vaccination cost of CVR was 2.53 USD, whilst OBH was 2.29 USD. Extrapolation to a two week India national campaign estimated that 1.1 million staff would be required using CVR, but 293,000 staff would be needed for OBH. OBH was operationally feasible, economical and effective at accessing the free roaming dog population. This study provides evidence for the continued expansion of research into the use of OBH as a supplementary activity to parenteral mass dog vaccination activities in India.

Development of a Non-Meat-Based, Mass Producible and Effective Bait for Oral Vaccination of Dogs against Rabies in Goa State, India

“…Intensive vaccination of 70% of the dog population has been demonstrated in focal projects in India, however the challenge of how to efficiently vaccinate large numbers of inaccessible dogs to achieve herd immunity remains. Combining parenteral and ORV methods may help to increase the feasibility of conducting mass dog vaccination at scale in such settings [21]. The egg-bait investigated in this study could provide an effective delivery vehicle for use in these approaches to finally break the deadlock and eliminate dog rabies from large areas.…”

“…Staff were trained in bait distribution methods as in a previous study of OBH methods in Goa State [21]. Briefly, staff were trained to approach dogs indirectly, avoiding eye-contact, dropping the bait in front of the dog whilst continuing to walk on and having the data collector watch the dog inconspicuously from a distance, recording their observations.…”

“…The OBH method was combined with the DD parenteral vaccination of accessible dogs. When compared with the existing CVR vaccination protocol, the OBH method was more efficient both in terms of human resource and estimated cost per dog vaccinated [21].…”

Modelling targeted rabies vaccination strategies for a domestic dog population with heterogeneous roaming patterns

“…The theoretical results in this study–targeting explorer or roamer dogs versus stay-at-home dogs–can be used to justify and direct future studies such as a cost-benefit analysis to help develop implementation of cost-efficient targeted reactive vaccination campaigns. For example, a recent study in India found that oral bait hand-outs vaccinated 35 dogs/person/day and was more cost-efficient when compared to a capture-vaccinate-release method (9 dog/person/day) for vaccinating roaming dogs that were difficult to handle or not at the owner’s residence [37].…”

Utilising Group-Size and Home-Range Characteristics of Free-Roaming Dogs (FRD) to Guide Mass Vaccination Campaigns against Rabies in India

“…In contrast, ORV should be adopted in areas where FRD are more likely to be sighted in groups. Gibson, Yale [50] demonstrated in Goa, India that Oral Bait Handout (OBH) vaccines are a viable option for the FRD that may be accustomed to human presence but resist retraining them for vaccine inoculation. Consequently, based on our findings of urban Panchkula we also suggest that, irrespective of the measure of the home-ranges, a high resight probability of FRD is indicative of a higher proportion of groups and hence ORV should be implemented to achieve adequate herd immunity.…”