Effect of removing Ascaris on the growth of Guatemalan schoolchildren

Abstract

Objective: To determine whether successful deworming for 6 months in children with high levels of Ascaris improves physical growth.

Subjects: Two hundred twenty-eight children (mean age, 9.7 years) in a highland Indian town in Guatemala.

Design: Children were randomly assigned to receive albendazole or placebo at baseline and 12 weeks. Children and field workers were both blind to the group assignment.

Outcome measures: Children's heights, weights, and mid-upper-arm circumferences were measured at baseline and 12 and 24 weeks. Fecal egg counts were taken at 0, 2, 12, 14, and 24 weeks to estimate the helminth burden (eggs per gram of feces [epg]).

Results: Baseline helminth prevalences were Ascaris, 91%, and Trichuris, 82%. Ascaris intensities were high: half of the children had moderate burdens (10 000 to 50 000 epg), and 25% had heavy burdens ( > 50 000 epg). Trichuris burdens were light (72% < 1000 epg). The albendazole and placebo groups did not differ at baseline in epg, age, anthropometry, or socioeconomic status. The two rounds of treatment successfully reduced the Ascaris burdens but had less effect on Trichuris. At 6 months the treatment group showed a small gain in weight (0.18 kg) compared with the placebo group but no improvement in height or mid-upper-arm circumference.

Conclusions: The successful removal of ascaris in a population of school-aged children with relatively high loads may have modest effects on weight gain. Ascaris is one of the most common infections in school-aged children, but its effect on the host may be less than that of other helminths.