Quantitative assessment of Ascaris lumbricoides infection in school children from a slum in Visakhapatnam, south India.

An epidemiological study was conducted on 217 school children aged between 7-13 years, from Relliveedhi a slum in Visakhapatnam, Andhra Pradesh, south India, during August 1993 to August 1994. The children belonged to a socioeconomically backward community-parental occupation being fishing or waged labor. Intensity and prevalence estimations for Ascaris lumbricoides were done indirectly by formalin-ethyl-acetate sedimentation technic and directly by worm expulsions following albendazole administration at a single oral dose of 400 mg/child. Prevalence rate was 73% while the intensity of infection ranged between low to moderate. Boys had severe infection than girls due to their outdoor activities and behavioral habits. Nine year old children had the highest prevalence rates. Mean Ascaris worm intensity was 2.2 (+/-1.91) with an over-dispersed distribution of the parasite in the host population. Reinfection study over a period of nine month showed that the prevalence rates exceeded the pre-intervention level but the intensity of infection was very low. Dual species intensity correlation between Ascaris and Trichuris was consistently strong.