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Does Deworming Improve Growth and School Performance in Children?

Taylor-Robinson, D., Jones, A. and Garner, Paul ORCID: (2009) 'Does Deworming Improve Growth and School Performance in Children?'. PLoS Neglected Tropical Diseases, Vol 3, Issue 1, e358.

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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. The World Health Organization (WHO) argues that “deworming helps meet the Millennium Development Goals”, in particular the six health-related goals:eradicate extreme poverty and hunger;achieve universal primary education;promote gender equality and empower women;reduce child mortality and improve maternal health; and combat HIV/AIDS, malaria, and other diseases. 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. This systematic review, published in The Cochrane Database and the BMJ, demonstrated uncertainty around the assumed benefit and concluded that it may be a potentially important intervention, but needed better evaluation.

The BMJ published a large number of letters that criticised the findings, including from authors at the World Bank, the WHO, the United States Centers for Disease Control and Prevention, and the Pan American Health Organization. We do not feel that these criticisms were scientifically substantive enough to undermine the method or the conclusion. For example, several critics commented on the fact that the systematic review could not make any conclusions about the long-term effects of treatment—but, as we argued in our reply to these criticisms, “we were unable to find any randomised controlled trials that evaluated long term benefit, and the evidence of short term benefit was not, for us, convincing.” The research community quite correctly carried out further randomised controlled trials (RCTs) of repeated doses in community trials with longer follow-up compared with no intervention or placebo. In light of this additional research, we have now updated the original Cochrane review. An author of one of the trials included in the 2000 review, Ed Cooper, criticised the review for not taking into account heterogeneity in parasite burdens. Therefore, in the recently updated review, we conducted an additional subgroup analysis at trial level stratified by worm intensity and prevalence.

Item Type: Article
Subjects: WA Public Health > WA 30 Socioeconomic factors in public health (General)
WA Public Health > WA 19 Schools, colleges, and specialized departments and facilities
WA Public Health > Health Administration and Organization > WA 525 General works
W General Medicine. Health Professions > Health Services. Patients and Patient Advocacy > W 84 Health services. Delivery of health care
QX Parasitology > Helminths. Annelida > QX 200 Helminths
W General Medicine. Health Professions > W 74 Medical economics. Health care costs
WA Public Health > Health Problems of Special Population Groups > WA 395 Health in developing countries
Faculty: Department: Groups (2002 - 2012) > International Health Group
Digital Object Identifer (DOI):
Depositing User: Philomena Hinds
Date Deposited: 18 Mar 2010 08:45
Last Modified: 06 Sep 2019 10:14


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