Rabies is an ancient viral zoonotic disease that is invariably fatal in humans and mammals. The disease circulates in two epidemiological cycles: an urban cycle involving maintenance of infection in dog populations and a sylvatic cycle involving wildlife. There is a possibility of spill-over of rabies virus from dogs to wildlife and vice versa.
Dogs are the most important rabies reservoir. Human cases have also been reported due to exposure to rabid cats and wildlife. Mongoose (Herpestes
spp.), jackals (Canis aureus
), foxes (Vulpes bengalensis
) and wolves (Canis lupus
) have been incriminated as wildlife reservoirs of rabies in Bangladesh, India, and Nepal [1
]. Recent studies on the Nepalese
field rabies virus indicate that it belongs to the Arctic fox genome [2
]. The rabies virus isolated from a human rabies case was 100% identical to viruses isolated from two dogs and a mongoose in Nepal [3
Dog bites are the primary source of human infection in all rabies endemic countries and account for 96% of rabies cases in the southeast Asia (SEA) region [4
]. Elimination of human rabies is dependent on elimination of dog rabies.
Countries can be categorized depending on rabies status: high, medium, and low rabies endemic countries and rabies-free countries. Maldives, Timor-Leste, and some islands of India are historically free of rabies. Bangladesh, India, and Myanmar are high rabies endemic countries. Bhutan, Nepal, and Sri Lanka are medium rabies endemic countries. Thailand is moving towards low endemic status, but due to increasing rabies incidence Indonesia is moving from a low endemic to a medium rabies endemic country. Rabies is an emerging disease problem on many islands of Indonesia which were previously considered rabies-free. Some countries have a comprehensive rabies control programme but it is a neglected disease problem in others due to competing public health priorities and the complex nature of rabies control activities.
Prevention of rabies in humans depends on a combination of interventions. These include provision of postexposure prophylaxis (PEP) to exposed patients, preexposure immunization of people at high risk of exposure, control of infection in animal reservoirs, and control of dog populations [5
]. Although rabies is preventable, the high cost of vaccines, compounded by the lack of education and awareness about the disease, limits the use of PEP. Recent studies show that most patients were victims of rabies due to negligence, ignorance, or the inadequate availability of primary health care services [4
Progress in preventing human rabies through control of the disease in its animal reservoir has been slow. This has been due to technical, intersectoral, organizational, and financial obstacles. In addition, there has been a lack of efficient dog rabies control campaigns including humane canine population management [6
]. The success and sustainability of dog immunization coverage depends heavily on appropriate management of the dog population. The efforts towards population management are limited and disjointed in most countries. Lethal methods of dog population control have been used in some countries which have been an expensive option. Attempts to control rabies through dog culling have not been sustainable or socially acceptable due to public, religious, and animal welfare concerns. Furthermore, surgical sterilization of dogs in small numbers and at irregular intervals does not yield any long-term benefits in reduction of the population. There are successful programmes of dog population control in limited urban areas coordinated by leading NGOs. However, they are location specific and have not been replicated at rural levels with community participation.