A review and meta‐analysis of the impact of intestinal worms on child growth and nutrition

Abstract

Table of Contents Summary1191. Introduction119 1.1 The gastrointestinal ecosystem119 1.2 Groups of intestinal parasitic worms that infect humans121 1.2.1 Flukes or trematodes121 1.2.2 Tapeworms or cestodes122 1.2.3 Roundworms or nematodes123 1.3 How worms may affect human nutrition and growth126 1.4 Design of studies estimating the impact of worms128 1.5 Aims1282. Factors affecting the impact of intestinal worms128 2.1 Species of intestinal worm128 2.2 Prevalence of infection129 2.3 Number and distribution of worms132 2.4 Duration of infection135 2.5 Rate of reinfection135 2.6 Summary1363. Factors affecting the impact of treatment137 3.1 Study design: controls and randomization138 3.2 Anthelmintic drugs138 3.3 Intervals between treatments141 3.4 Duration of follow‐up142 3.5 Outcomes measured and the need for controls142 3.6 Initial nutritional status143 3.7 Age of subjects144 3.8 Remedial therapy after treatment144 3.9 Summary1454. Aims and methods of the meta‐analysis145 4.1 Search terms145 4.2 Inclusion criteria146 4.3 Exclusion criteria147 4.4 Meta‐analysis1475. Results of the meta‐analysis147 5.1 Geographic origin of studies150 5.2 Estimates of effects150 5.3 The figures and how to interpret them150 5.4 Sources of error or bias1506. Discussion153 6.1 Magnitude of effects153 6.2 Treatment alone is not enough159 6.3 The Cochrane Collaboration Review161 6.4 Characteristics of an ideal study162 6.5 Implications for programmes163 6.6 Conclusions166Acknowledgements167References167Appendix: Summary of papers identified for the review177 Summary More than a half of the world's population are infected with one or more species of intestinal worms of which the nematodes Ascaris lumbricoides, Trichuris trichiura and the hookworms are the most common and important in terms of child health. This paper: (1) introduces the main species of intestinal worms with particular attention to intestinal nematodes; (2) examines how such worms may affect child growth and nutrition; (3) reviews the biological and epidemiological factors that influence the effects that worms can have on the growth and nutrition of children; (4) considers the many factors that can affect the impact of treatment with anthelmintic drugs; (5) presents the results of a meta‐analysis of studies of the effect of treating worm infections on child growth and nutrition; (6) discusses the results in terms of what is reasonable to expect that deworming alone can achieve; (7) describes some important characteristics of an ideal study of the effects of deworming; and (8) comments on the implications for programmes of recommendations concerning mass deworming.

Adverse drug reactions in Ghanaian children: review of reports from 2000 to 2012 in VigiBase

“…The first nationwide programme to deworm children in Ghana was initiated in 2007. However, the programme was derailed due to bad media publicity on rumours of death associated with the drugs used for the programme [34,35]. It is possible that these deaths may be linked to the programme or that the reporting of these cases was occasioned by the bad publicity.…”

Assessing the zoonotic potential ofAscaris suumandTrichuris suis: looking to the future from an analysis of the past

“…infections are associated with diarrhoea, malnutrition, impaired growth and development, and can lead to death (De Silva et al, 1997;Bethony et al, 2006;Hall et al, 2008;Dold & Holland, 2011). The burden of these two helminth infections has been estimated at around 17 million disability-adjusted life years (DALY), which is half the estimate for malaria (Chan, 1997), but there are substantial difficulties in generating DALY estimates due to the non-specific and insidious nature of much of the morbidity associated with intestinal helminth infections and uncertainty about the numbers of individuals infected (Brooker, 2010).…”

Household and personal factors are sources of heterogenity in intestinal parasite clearance among Mexican children 6–15 months of age supplemented with vitamin A and zinc

“…The high prevalence of recurrent intestinal parasite infections among children in these countries leads to increased malnutrition and so has an important effect on childhood growth and development (Hall A et al, 2008). Preventive chemoprophylaxis is an effective public health intervention in reducing parasite burden and improving childhood nutritional status (Montresor A et al, 2012;Webster JP et al, 2014).…”