Global evidence
In a systematic review of 25 studies that assessed the nutritional effect of deworming in children (Dickson et al, 2000), analysis of growth outcomes in children aged 1–16 years suggested that one dose was associated with an average 0·24 (95% CI 0·15–0·32) kg increase in weight. Another systematic review of deworming assessed the effect on hemoglobin and anaemia rates (Gulani et al, 2007). The positive effects, although small, could translate into a 5–10% reduction in rates of anaemia in populations with high rates of intestinal helminthiasis.
Two studies assessed the effect of deworming interventions during pregnancy (Torlesse et al 2001; Larocque et al 2006). There was a mean fall in hemoglobin concentration between first and third trimester in women who received albendazole of 6·6 g/L less than in women who received placebo (p=0·003).