Deworming drugs for soil-transmitted intestinal worms in children: effects on nutritional indicators, haemoglobin, and school performance

Abstract

Background The World Health Organization (WHO) recommends treating all school children at regular intervals with deworming drugs in areas where helminth infection is common. As the intervention is often claimed to have important health, nutrition, and societal effects beyond the removal of worms, we critically evaluated the evidence on benefits. Objectives To summarize the effects of giving deworming drugs to children to treat soil‐transmitted helminths on weight, haemoglobin, and cognition; and the evidence of impact on physical well‐being, school attendance, school performance, and mortality. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register (14 April 2015); Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library (2015, Issue 4); MEDLINE (2000 to 14 April 2015); EMBASE (2000 to 14 April 2015); LILACS (2000 to 14 April 2015); the meta Register of Controlled Trials ( m RCT); and reference lists, and registers of ongoing and completed trials up to 14 April 2015. Selection criteria We included randomized controlled trials (RCTs) and quasi‐RCTs comparing deworming drugs for soil‐transmitted helminths with placebo or no treatment in children aged 16 years or less, reporting on weight, haemoglobin, and formal tests of intellectual development. We also sought data on school attendance, school performance, and mortality. We included trials that combined health education with deworming programmes. Data collection and analysis At least two review authors independently assessed the trials, evaluated risk of bias, and extracted data. We analysed continuous data using the mean difference (MD) with 95% confidence intervals (CIs). Where data were missing, we contacted trial authors. We used outcomes at time of longest follow‐up. The evidence quality was assessed using GRADE. This edition of the Cochrane Review adds the DEVTA trial from India, and draws on an independent analytical replication of a trial from Kenya. Main results We identified 45 trials, including nine cluster‐RCTs, that met the inclusion criteria. One trial evaluating mortality included over one million children, and the remaining 44 trials included a total of 67,672 participants. Eight trials were in children known to be infected, and 37 trials were carried out in endemic areas, including areas of high (15 trials), moderate (12 trials), and low prevalence (10 trials). Treating children known to be infected Treating children known to be infected with a single dose of deworming drugs (selected by screening, or living in areas where all children are infected) may increase weight gain over the next one to six months (627 participants, five trials, low quality evidence ). The effect size varied across trials from an additional...

Sanitation, hookworm, anemia, stunting, and wasting in primary school children in southern Ethiopia: Baseline results from a study in 30 schools

“…These have found that mass treatment appears to have little to no effect on height or weight [62, 63], or hemoglobin [62], but that it is possible that targeted treatment of infected children does increase their weight gain, over the following six months [62]. These findings are broadly in line with ours.…”

Soil‐transmitted Helminthiasis in India

“…The chronic nature of STHs results in the greatest burden of disease and morbidity (WHO, 2012). Long-term effects of parasite infestation include anemia, impaired nutritional status (particularly micronutrient deficiency), diminished physical and cognitive development, and poor academic performance (Taylor-Robinson et al, 2015). The global strategy to manage STHs involves three interventions: (a) regular treatment with anthelminthic medications, (b) health education, and (c) environmental sanitation and personal hygiene (Mascarini-Serra, 2011).…”

“…The parasites are transmitted by soil contaminated with human feces containing eggs of the STHs (WHO, 2012). Children in developing countries are particularly susceptible to intestinal parasites because of inadequate sanitation, insufficient access to clean water, malnutrition, poor personal hygiene, overcrowded living conditions, lack of access to health care, and illiteracy (Strunz et al, 2014;Taylor-Robinson, Maayan, Soares-Weiser, Donegan, & Garner, 2015).…”

Effects of school-based physical activity and multi-micronutrient supplementation intervention on growth, health and well-being of schoolchildren in three African countries: the KaziAfya cluster randomised controlled trial protocol with a 2 × 2 factorial design

“…Third, micronutrient-supplementation randomised controlled trials (RCTs) showed a modest, but significant protective effect on helminth infection and reinfection rates [32]. Fourth, periodic deworming has not translated into the expected health gains according to recent systematic reviews and meta-analyses [33,34]. One reason for this may be the concurrent problem of malnutrition and underlying micronutrient deficiencies, which makes it difficult for children to compensate for delays in growth and development that resulted from infectious diseases.…”