Research Article: Effects of Deworming on Malnourished Preschool Children in India: An Open-Labelled, Cluster-Randomized Trial

Date Published: April 16, 2008

Publisher: Public Library of Science

Author(s): Shally Awasthi, Richard Peto, Vinod K. Pande, Robert H. Fletcher, Simon Read, Donald A. P. Bundy, Peter J. Hotez

Abstract: BackgroundMore than a third of the world’s children are infected with intestinal nematodes. Current control approaches emphasise treatment of school age children, and there is a lack of information on the effects of deworming preschool children.MethodologyWe studied the effects on the heights and weights of 3,935 children, initially 1 to 5 years of age, of five rounds of anthelmintic treatment (400 mg albendazole) administered every 6 months over 2 years. The children lived in 50 areas, each defined by precise government boundaries as urban slums, in Lucknow, North India. All children were offered vitamin A every 6 months, and children in 25 randomly assigned slum areas also received 6-monthly albendazole. Treatments were delivered by the State Integrated Child Development Scheme (ICDS), and height and weight were monitored at baseline and every 6 months for 24 months (trial registration number NCT00396500). p Value calculations are based only on the 50 area-specific mean values, as randomization was by area.FindingsThe ICDS infrastructure proved able to deliver the interventions. 95% (3,712/3,912) of those alive at the end of the study had received all five interventions and had been measured during all four follow-up surveys, and 99% (3,855/3,912) were measured at the last of these surveys. At this final follow up, the albendazole-treated arm exhibited a similar height gain but a 35 (SE 5) % greater weight gain, equivalent to an extra 1 (SE 0.15) kg over 2 years (99% CI 0.6–1.4 kg, p = 10−11).ConclusionsIn such urban slums in the 1990s, five 6-monthly rounds of single dose anthelmintic treatment of malnourished, poor children initially aged 1–5 years results in substantial weight gain. The ICDS system could provide a sustainable, inexpensive approach to the delivery of anthelmintics or micronutrient supplements to such populations. As, however, we do not know the control parasite burden, these results are difficult to generalize.Trial NCT00396500

Partial Text: Intestinal nematodes are amongst the most common agents of chronic infection in low income countries [1]. In India, it has been reported that about half the population is infected with round worm (Ascaris lumbricoides), whipworm (Trichuris trichiura) and/or hookworm (Necator americanus, Ancylostoma duodenale) [2]. These infections could have significant effects on the development of children [3]. Any effects on physical development would typically be subtle and chronic, manifesting as longstanding anaemia [4]–[6], reduced physical fitness [7], and somewhat constrained growth [8]. There might also be subtle, but important developmental effects on cognition and educational achievement [9]–[11]. Recognition of these potential consequences of infection has led to increasing emphasis on community-based anthelmintic treatment to reduce worm burdens in children irrespective of direct evidence of infection, particularly children of school age [1],[3],[12],[13].

We conducted an open-labelled, cluster-randomized trial within the ICDS infrastructure in urban Lucknow UP with the hypotheses that the ICDS could deliver anthelmintics regularly to pre-school children in the urban slums of Lucknow, and that if they did then this would result in a growth benefit (trial registration number NCT00396500). We obtained approval from the institutional human ethics committee in Lucknow. The primary objective was to assess the impact of 6 monthly deworming on weight and height gain over 2 years in children initially aged 1 to 5 years of age. The protocol for this trial and supporting CONSORT checklist are available as Supporting Information; see Protocol S1 and Checklist S1.

A total of 3935 children, aged 1 to 5 years at entry, 1967 from 25 anganwadi centers allocated “usual care” and 1968 from 25 anganwadi centers allocated “usual care plus albendazole” were enrolled in the study from April to August, 1994 and followed up until December, 1996 (Figure 1). Relative to WHO reference standards, the point prevalence at baseline of underweight was 49% (1924 children), stunting 63% (2471), and wasting 18% (699). The children were all from families with incomes below the national poverty level, and 51% were girls. The children were treated and surveyed 5 times (at 0, 6, 12, 18 and 24 months) and anthropometric data were collected on all 5 occasions from 95% (3712/3912) of the surviving children in each arm of the study. At 24 months, 99% (3855/3912) of the surviving children were measured. There were 23 deaths in 2 years, of which 13 were in the usual care arm and 10 were in the arm receiving usual care plus albendazole.

These results suggest that, at the time of the study (mid 1990s), 6 monthly deworming as a part of an ICDS program in these urban slums in north India was associated with substantial weight gain in malnourished pre-school children. The mechanism for this gain was not assessed by the present study design as we have no measure of faecal worm egg counts, but it may reflect a direct effect of deworming on nutrition. The effect may also be indirect since a negative association between ascariasis and vitamin A absorption has been described [18], but a study in an area of low infection prevalence showed a benefit of vitamin A supplementation that was not further enhanced by deworming [19].



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