Community incidence of snakebite and envenoming in Sri Lanka; results of a national survey

Abstract

INTRODUCTION AND OBJECTIVES: We undertook the first ever country-wide community-based survey to determine the incidence of snakebite in Sri Lanka. METHODS: Data were collected through household interviews by trained data collectors.125 clusters were allocated to each of the 9 provinces of the country. Within each province the clusters were divided among the districts in proportion to their population. A Grama Niladhari (GN) division was defined as a cluster for data collection. The clusters were selected using simple random sampling, and in each cluster 40 households were sampled consecutively from a random starting point. RESULTS: Data relating to 165,665 individuals (0.8% of the population of Sri Lanka) living in 44,136 households in 1,118 clusters was collected from June 2012 to May 2013. 695 (males 418) snakebites and 323 (males!93) significant envenomings (local tissue necrosis or systemic envenoming) were reported during the 12 months preceding the interview. The overall community incidence of snakebites and significant envenoming were 398 and 151 per 100,000 population, respectively. 446 (64.2%) bites and 208 (64.4%) envenomings were in people aged 30 to 59 years. There was wide variation between districts, the worst affected being Mullaitivu, Anuradhapura, Batticaloa, and Poionnaruwa, ali in the dry zone, mainly agricultural areas of the country. CONCLUSIONS: Sri Lanka has a high community incidence of snakebite and envenoming with a marked geographical variation.This variation underlines both the inaccuracy of extrapolating data of localised surveys to national or regional levels and the need to prioritise distribution of resources for treatment of snakebite even in small countries.