A controlled chemotherapeutic intervention trial on the relationship between Ascaris lumbricoides infection and malnutrition in children.

A 2-year investigation, consisting of a controlled, non-blind, 3-monthly chemotherapeutic intervention trial, based on transmission dynamics of Ascaris lumbricoides infection, was undertaken to prove or refute the role of A. lumbricoides as a contributor to childhood malnutrition. The study involved 1206 children aged 2-12 years in 21 villages in Myanmar [Burma] starting in August 1984. The intervention and non-intervention villages were comparable regarding almost all the important baseline variables, including prevalences of Ascaris infection (80.8 vs 83.0%) and of malnutrition of grade 2 and above for height-for-age (58.4 vs 55.8%) and for weight-for-age (48.2 vs 47.8%). The intensity of Ascaris infection was related to the degree of malnutrition. A significant increment of height gain was found, starting after the 6th month, and of weight gain after the 24th month, of the study among the treated 2-10 years old children when compared with the non-treated ones. By the end of 24 months, the height and weight gains per child were 0.65 cm and 0.93 kg respectively. Lesser increments in height-for-age and weight-for-age were also observed after successive treatments among the treated children with initially higher mean worm burdens. The findings are discussed in the context of causal relationship between ascariasis and malnutrition in children.