Community incidence of snake bite in Sri Lanka

Abstract

There are few studies on community incidence of snake bite. There are no national level data. We undertook a community-based country-wide survey on snake bite in Sri Lanka. The survey was designed to sample 1% of the population of Sri Lanka. A Grama Niladhari (GN) division was defined as a cluster for data collection. 125 clusters were allocated to each province. The clusters were selected using simple random sampling and in each cluster, 40 households were sampled consecutively from a random starting point. Population based incidence rates of snake bite were then constructed. 1,125 GN divisions with 43,827 households and a population of 164,746 (0.81% of country’s population) were surveyed. 694 snakebites and 317 significant envenoming (local tissue necrosis and systemic envenoming) were reported within the past 12 months. The crude overall community incidence of snake bites and significant envenoming were 421 and 192 per 100,000 population, respectively. There was wide variation within districts, the worst affected being Mullaitivu, Anuradhapura, Batticaloa and Polonnaruwa, all mainly agricultural areas in the Dry Zone of the country. It is concluded that Sri Lanka has a high community incidence of snake bite and envenoming, with marked geographical variation within the country.