Free-roaming dogs and canine rabies in India
Our overarching goal is to make a major contribution to eliminating dog-mediated human rabies deaths in the Indian subcontinent by identifying optimal strategies for interrupting dog-to-dog transmission of rabies virus in resource limited settings. The World Health Organization (WHO) has set the goal of zero human deaths from dog-mediated rabies by 2030.
Rabies kills an estimated 59,000 people every year (20,000 in India), and most of these deaths are from the poorest sectors of society. As dogs are the principal reservoir of rabies in low-and middle-income countries in Asia and Africa, interrupting transmission of rabies in this reservoir population should address the source of the problem and provide long-term public health and economic benefits. The proposed mechanism for accomplishing this is through vaccinating dogs at high enough coverage (70%) to achieve herd immunity.
Achieving and sustaining high vaccination coverage across large geographic scale presents a daunting challenge for a country like India which has the largest free-ranging dog population in the world (59 million). Dogs are often loosely owned by the communities, thus there is a reliance on community participation to access dogs. High population turnover rates of free-ranging dog populations further add to the logistical difficulties of sustaining vaccination coverage. Thus current approach to eliminating rabies by rapidly vaccinating 70% of the dogs is unrealistic in India. At present, rabies and dog population control programs in India are limited to a few urban centers. Such ‘top down’ approaches (mass dog vaccination funded and implemented by non-government organizations) may seem promising in the shorter term, but a smarter, more nuanced strategy is necessary for sustained control of canine rabies at a larger geographic scale.
What is needed is a strategy that will ensure efficient allocation of resources for sustainable gains. We need to know where and how the virus persists and by what pathway of transmission it arrives in rural places, as most dog-mediated human rabies deaths occur in rural areas of India.
Central Hypothesis: Our scientific hypothesis is that rabies arrives recurrently in rural dog populations through stepping-stone dispersal originating in urban populations where the disease is endemic. Because dog population size is large in urban areas and small in rural villages, we also hypothesize that stochasticity is important in persistence (or lack thereof).
Using whole genome sequencing of rabies virus isolates, we hope to elucidate population structure and dispersal patterns of rabies virus along urban-rural gradient. Our field-based research will investigate dog demography using mark-resight techniques. We are developing epidemiological models of rabies dynamics to understand persistence and transmission, and to compare interventions. The models are being used to compare alternative interventions: where and when should we vaccinate, deploy animal birth control, promote garbage management, and focus monitoring. We will leverage these results in a larger proposal where we will scale up to the national level.
Free-roaming dog population management is an important component of human rabies elimination efforts: https://avbelsare.netlify.app/publication/dpopm/
Free-roaming dogs are also responsible for serious and fatal attacks on humans. Here’s a link to published reports from India in 2022: https://anyadoc.github.io/FRDattacks-India/