Estimates of disease burden due to snakebite in Sri Lankan hospitals

Abstract

INTRODUCTION: There have been no country-wide studies or estimates of disease burden due to snakebite in Sri Lankan hospitals. OBJECTIVES: To assess disease burden due to snakebite and estimate relative frequency of the biting species in hospitals situated in different parts of the country. METHODS: Hospital morbidity and mortality data on snakebite was obtained for each administrative district. Sri Lanka was divided into 5 zones based on climate and available data on snake habitat (Zone 1-wet zone altitude <900m; Z2-intermediate zone; Z3-dry zone, Z4-wet zone altitude >900m; Z5-northern and north-western dry zone). Administrative districts were allocated to zones based on their geographical location and population using geographical information systems technology. Hospital morbidity and mortality data were collated for the 5 zones. A survey among physicians (37 physicians in 42 hospitals covering the 5 zones) was used (Delphi technique) to estimate the proportion of snakebites by different species and requirement of hospital resources, in each zone. Results: There was a clear difference in incidence of hospital admissions due to snakebite in the different zones (Z3-3.5 and Z4-0.4 per 1000 population). The distribution of bites by individual species also varied between zones (deadly venomous species Z3-85%, Z2-45%), moderately venomous and mildly-venomous species Z4-100%, Zl-70%). These trends corresponded to estimates of requirements for AVS and other hospital facilities (in 2000, Z3-86100 vials of AVS, 7380 Intensive care unit patient-days; Zl-26400 vials of AVS, 2640ICU patient-days). CONCLUSIONS: Incidence of hospital admissions due to snakebite and estimates of relative medical importance of different snake species show geographic variation within the country. This is reflected in estimates of requirements for facilities. Zoning based on environmental information rather than on political boundaries could lead to better distribution of health care resources for management of snakebite in hospitals situated in different parts of the country.