Epidemiology

Abstract

Rabies is widely distributed with the exception of only a few countries. People of all age groups are susceptible but children are at a greater risk. Rabies is maintained in two epidemiological cycles, urban cycle and sylvatic cycle. Dogs are the main reservoir hosts in the urban cycle which predominates in India and many other developing countries in Asia, Africa, and Central and South America. Sylvatic cycle is predominant in Europe and North America because of successful control of dog rabies. In some regions including India, sylvatic cycle operates simultaneously with the urban cycle, making the epidemiology of rabies more complex. The maximum burden of rabies lies in Asia followed by Africa, while rabies is endemic in animal populations in many European countries. In Latin America, rabies circulates in dogs and bats. Bats are the source of most human rabies cases in the USA and Canada. Bats in Australia have been found to carry Australian bat lyssavirus. A variety of bat lyssaviruses have also been documented in Africa. Due to the recent reports of Asian bats maintaining lyssaviruses, interest in the role of bats in rabies transmission has increased in Asia.