Epidemiology of Soil-transmitted Helminthiasis in remote areas and spacial analysis using a geographic information system, Chiang Mai Province

Abstract

The purpose of this study was to determine the prevalence of soil-transmitted helminthiasis in remote areas of Chiang Mai Province and spatial analysis using a Geographic Information System. A total of 1,719 cases from 15 villages in 10 districts, Chiang Mai province were included in this study. Stool samples were examined by Kates thick smear. The study was carried out from January to December 2007. The overall prevalence of soil transmitted helminthic (STH) infections was 53.5% (920/1,719). The predominant helminth infection found was hookworm infection 25.78% (443/1,719), ascariasis and trichuriasis 23.95 (410/1,719) and 13.88 (230/1,719), respectively. The prevalence was highest between the ages of 15 and 19 years, being 59.62% and lowest among children 0-4 years old, being 34.41%. There was no statistically significant difference between the prevalence in males and females (p>0.05) while prevalence among different age groups, tribes and villages were statistically significant (p<0.05). The application of Geographic Information Systems (GIS) with soil-transmitted helminths revealed that the hookworm infection was highest in north zone, ascariasis was highest in southern part, and district in middle location near the city had low prevalence. This was illustrated by bar graph on a map in GIS. Spatial analysis is valuable and useful for interpretation in relation to geography and the other areas which have similar environment for STH infection lead to prevention can control measure plan of the 51"II transmission.