Some epidemiological aspects of hookworm infection among the rural population of Bali, Indonesia.

Stool examination using direct smear method, Kato-Katz thick smear technique and modified Harada Mori test tube cultivation method were done on 2,331 people among the rural population of Bali. The serum ferritin was examined by ELISA technique and hemoglobin concentration by cyanmethemoglobin technique. Overall prevalence of hookworm infection was 24.02% with heterogeneity in local prevalences. The highest prevalence was found in wet highland area (46.3%), followed by wet lowland (27.7%), dry highland (14.2%) and dry lowland (10.9%). The majority of hookworm infection cases were associated with Ascaris and Trichuris infections. Most of the hookworm infections (73.3%) were light/very light in intensity with a mean EPG of 619. The prevalence and intensity of infection were increasing with age, and the age-prevalence and age-intensity curves were slightly convex. There was no significant difference of prevalence or intensity of infection between males and females. The condition and humidity of soil found to be an important determinant for prevalence of hook-worm infection. The frequency distribution of the intensity of hookworm infection showed an over-dispersed distribution pattern with 10% of people harboring more than 63% of parasite burden as measured by EPG. The prevalence of anemia was higher, but not statistically significant, in hookworm infected persons compared with people without infection. But this study failed to show a significant correlation between intensity of infection with hemoglobin level. There was a significant correlation between serum ferritin level with intensity of infection.