Ascaris and Trichuris do not contribute to growth retardation in primary school children.

To access the effectiveness of the treatment of soil-transmitted helminthiasis (STH) on the growth of primary school children, 353 children were block stratified to receive either mebendazole plus pyrantel oxantel pamoate every three months or a placebo. The children were followed for two years with 89% completing the trial. Follow-up stools indicated that the treatment was efficacious for ascariasis and trichuriasis. There was virtually no hookworm infection. The children were malnourished as measured by the number below -2 SD of height and weight standards. There was no difference in height or weight between the treatment and control groups by sex initially or at the end of two years of follow-up. The treatment of Ascaris and Trichuris had no effect on growth parameters. The effect of STH on growth may be mediated through hookworm infections.