A community-based cross-sectional survey was conducted in 4 townships of Yangon Region (2 townships with highest incidence and 2 townships with lowest incidence of snakebite) from March to June 2018. According to the hospital statistics (2016), Hlegu and Taikkyi townships were reported to have the highest incidence and Dagon Myothit (East) and Thongwa townships the lowest incidence of snakebites. These 4 townships were purposely selected in this study. Study population consisted of all males and females older than 5 years who resided in the sampled households for last one year.
Sample size and sampling
Sample size is calculated based on the estimated prevalence of snake bite (16.2 per 100,000 population) and 2016 incidence in Yangon of 10.2/100,000, assumed household size of 3.5. After getting sample size, power of the study is resulted as 0.9. In each study township, at least 10 clusters (ward/village) (7 villages and 3 wards chosen to get 70:30) were selected randomly. Then, 50 households were randomly selected from each cluster. Assuming that there would be about 3.5 persons in each household, total number of sample size would become 1750 in each township.
Data was collected using a pre-tested questionnaire. The questionnaires were admi-nistered by primary health care workers, midwives and health assistants employed at health centers in the study townships. Data collectors were trained by the research team before the field survey. For each household, an adult member was interviewed and he/she had to answer for every member who spent the past year in the selected household.
Information was collected on socio-demo-graphics (age, sex, occupation, marital status, household income of respondents), snakebites (type of snake, site of bite, place and time of bite), their consequences (significant envenoming, death) and treatment seeking behavior. Significant envenoming was defined as the presence of local tissue necrosis at the site of bite, presence of neurotoxicity, nephrotoxicity or bleeding manifestations.
Data entry and analysis was performed in SPSS version 20 after checking for errors and inconsistencies. The incidence rates of snakebite, envenoming and death with 95% confidence intervals were calculated.
The study was approved by the Ethics Review Committee of University of Medicine 1, Yangon. Informed consents were taken from the participants after thorough explanation about the study.