Does deworming improve growth and school performance in children?

The World Bank ranks soil-transmitted helminth infection as causing more ill health in children aged 5–15 years than any other infection. In light of this ranking, global agencies recommend regular, mass treatment with deworming drugs to children in developing countries [1,2]. The World Health Organization (WHO) argues that ‘‘deworming helps meet the Millennium Development Goals’’ [3], in particular the six health-related goals: (1) eradicate extreme poverty and hunger; (2) achieve universal primary education; (3) promote gender equality and empower women; (4 and 5) reduce child mortality and improve maternal health; and (6) combat HIV/ AIDS, malaria, and other diseases (http:// www.un.org/millenniumgoals). However, deworming campaigns cost money to deliver, and so we must be clear that WHO statements about the impact of these programmes are based on reliable evidence. In 2000, we systematically reviewed the reliable evidence from relevant controlled trials about the effects of anthelminth drugs for soil-transmitted helminth infection on child growth and cognition [4]. This systematic review, published in The Cochrane Database and the BMJ [4,5], demonstrated uncertainty around the assumed benefit and concluded that it may be a potentially important intervention, but needed better evaluation.