Prevalence, vulnerability and epidemiological characteristics of snakebite in agricultural settings in rural Sri Lanka: A population-based study from South Asia.

Subashini Jayawardana,Thashi Chang,Ariaranee Gnanathasan,Carukshi Arambepola,José María Gutiérrez

doi:10.1371/journal.pone.0243991

Abstract

BackgroundThe burden of snakebite remains poorly characterised because of the paucity of population-based data. Further, factors determining the vulnerability of individuals within rural communities to snakebite have been rarely investigated. We undertook a population-based study to determine the prevalence, vulnerability and epidemiological characteristics of snakebite in rural Sri Lanka.Methods and findingsA population-based cross-sectional study was conducted among 8707 current residents in the district of Ampara, representing typical rural Sri Lanka. The sample was recruited using multi-stage cluster sampling with probability proportionate-to-size. Snakebite victims were identified using the WHO criteria. Data were collected using a pre-tested interviewer-administered questionnaire.Each household had on average 3.8 persons; mean age 28.3 years (SD = 18.2); 51.3% males. The one-year point prevalence of snakebites was 17.6 per 1000 residents (95% CI: 15–20.6) and 6.12 per 100 households (95% CI: 5.25–7.13), while the lifetime prevalence was 9.4 per 100 residents (95% CI: 8.8–10.0) and 30.5 per 100 households (95% CI: 28.6–32.2) with a case fatality ratio of 0.033. Venomous snakebites accounted for 28.1%; snakes were unidentified among 30.1%. Compared to the non-snakebite victims, being single, males, of Sinhala ethnicity, aged >19 years, low education and socioeconomic status, engaging in farming or unskilled outdoor occupations denoted vulnerability to snakebites. Outdoor bites (77.8%) were more common among males; during daytime; mostly while walking; within the rural terrains and home gardens; on lower limbs; mostly by hump-nosed and Russell viper. Indoor bites were more common among females; during night-time; while sleeping and barefooted; on lower limbs; mostly by hump-nosed vipers, kraits and non-venomous snakes.ConclusionsThe burden of snakebite is considerably high among rural populations. The concept of vulnerability can be useful in healthcare decision-making and resource allocation.

Highlights

Snakebite is a neglected tropical disease with an estimated 1.2–5.5 million snakebites per year resulting in 0.42 million envenomings and 0.02 million deaths worldwide [1]
The concept of vulnerability can be useful in healthcare decision-making and resource allocation
Of the 2500 households sampled, those ever reporting a victim of snakebite was 763, giving a lifetime prevalence of 30.5 per 100 rural households

Summary

Introduction

Snakebite is a neglected tropical disease with an estimated 1.2–5.5 million snakebites per year resulting in 0.42 million envenomings and 0.02 million deaths worldwide [1]. A recent island-wide survey reported an estimated incidence of over 80,000 bites, 30,000 envenomings and 400 deaths per year, predominantly among rural residents engaged in agriculture related occupations [8]. Venomous snakes are usually encountered in sub-standard housing conditions or as an occupational hazard during agricultural work in paddy fields, chena cultivation and forestry. Owing to this wide variation in snake habitats and biting habits, distinct differences may exist within rural areas in relation to the individuals more at risk of snakebites compared to those who are not. We undertook a population-based study to determine the prevalence, vulnerability and epidemiological characteristics of snakebite in rural Sri Lanka

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Conclusion