An 18-month study of the effect of periodic anthelminthic treatment on the growth and nutritional status of pre-school children in Bangladesh.

An 18-month study was conducted from February 1989 to August 1990 to examine the effect of regular deworming on child growth and nutritional status. A sample of 1402 children, from 2 to 6 years old, were divided into a treatment group and a control group. The 688 children in the treatment group received a 500 mg single dose of mebendazole, while the 714 children in the control group were given a placebo. Height, weight and mid-upper arm circumference (MUAC) were measured on monthly household visits. Growth was measured in terms of the change in height-for-age, weight-for-age, weight-for-height and MUAC over 18 months. The initial prevalence of infection was estimated from a random sample of 96 children (49 treated, 47 control). The initial overall prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm was 71, 44 and 10% respectively. The final prevalence of infection, estimated from a random sample of 265 children, was A. lumbricoides 6%, T. trichiura 6% and hookworm 2% in the mebendazole group compared with 64, 18 and 19% respectively in the placebo group. Despite the successful treatment of helminths, there was no significant improvement in the growth of treated children compared with their untreated counterparts in terms of the change in z-scores of height-for-age, weight-for-age, weight-for-height and MUAC. The factors which may have contributed to this outcome are discussed.