Geohelminthic infection in an estate child population in Sri Lanka: association with hygienic practices and eosinophil counts

Abstract

OBJECTIVES: To describe hygienic practices, prevalence of geohelminthic infections and its association with eosinophil counts among children. Methods: A descriptive cross sectional study was conducted in a tea plantation in Ratnapura District involving 316 school children. An interviewer-administered questionnaire was used to collect data from the child or parent. Stool and blood samples were obtained from all the consenting children. Stool examinations were conducted using saline smear, agar-plate culture technique, and Kato-Katz quantitative technique. Eosinophil count was obtained using blood smears. RESULTS: Mean age of the children (n=317) in the sample was 8.5 years (SD 1.7). Of the selected sample 219(85%) had access to pipe borne water, 228(72%) washed hands before meals, 164(52%) did not use a toilet, 180(57%) had a domesticated dog or a cat and 168(53%) used antihelminthic drugs regularly. A history of asthma, wheezing/allergies was reported by 101(32%) subjects. Of the 317 stool samples examined, Ascaris infection was prevalent in 60(19%), hookworm infection in 25(8%) (15 of them had>4000 eggs per gram - severe infection), Trichuris infection in 7(2.2%) and Strongyloides infection in 3(0.9 %) children. Of the 298 blood samples examined 12 (4%) had an eosinophil count of > 16 %( severe eosinophilia). A statistically significant association was observed with hookworm infection and increased eosinophil counts (p=0.006). CONCLUSION: Prevalence of geohelminthic infections was low among this population, Ascaris showing the highest prevalence (n~60, 19%). An association between the presence of helminthic infection and an increased eosinophil count was observed only with hookworm infection in which (n= 15)60% reported a severe degree of infection.