Vivian A Welch1, Elizabeth Ghogomu2, Alomgir Hossain3, Shally Awasthi4, Zulfiqar A Bhutta5, Chisa Cumberbatch6, Robert Fletcher7, Jessie McGowan8, Shari Krishnaratne9, Elizabeth Kristjansson10, Salim Sohani11, Shalini Suresh2, Peter Tugwell12, Howard White13, George A Wells14. 1. Bruyère Research Institute, Ottawa, ON, Canada; School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, ON, Canada. Electronic address: vivian.welch@uottawa.ca. 2. Bruyère Research Institute, Ottawa, ON, Canada. 3. Cardiovascular Research Methods, University of Ottawa Heart Institute, Ottawa, ON, Canada. 4. Department of Pediatrics, King George's Medical University, Lucknow, India. 5. Research Centre for Global Child Health and Child Health Evaluative Sciences, The Hospital for Sick Children, and Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada; Division of Epidemiology, Dalla Lana School of Public Health, Toronto, ON, Canada; Center of Excellence in Women and Child Health, Aga Khan University, Karachi, Pakistan. 6. Epidemiology Research Institute, Tropical Medicine Research Institute, The University of West Indies, Kingston, Jamaica. 7. Harvard Medical School and Harvard Pilgrim Healthcare Institute, Boston, MA, USA. 8. School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, ON, Canada. 9. London School of Hygiene & Tropical Medicine, London, UK. 10. School of Psychology, Centre for Research on Educational and Community Services, University of Ottawa, Ottawa, ON, Canada. 11. International Operation Canadian Red Cross Society, Ottawa, ON, Canada. 12. Bruyère Research Institute, Ottawa, ON, Canada; Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada. 13. Campbell Collaboration, Oslo, Norway. 14. School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, ON, Canada; Cardiovascular Research Methods, University of Ottawa Heart Institute, Ottawa, ON, Canada.
Abstract
BACKGROUND: Soil-transmitted helminthiasis and schistosomiasis, considered among the neglected tropical diseases by WHO, affect more than a third of the world's population, with varying intensity of infection. We aimed to evaluate the effects of mass deworming for soil-transmitted helminths (with or without deworming for schistosomiasis or co-interventions) on growth, educational achievement, cognition, school attendance, quality of life, and adverse effects in children in endemic helminth areas. METHODS: We searched 11 databases up to Jan 14, 2016, websites and trial registers, contacted authors, and reviewed reference lists. We included studies published in any language of children aged 6 months to 16 years, with mass deworming for soil-transmitted helminths or schistosomiasis (alone or in combination with other interventions) for 4 months or longer, that reported the primary outcomes of interest. We included randomised and quasi-randomised trials, controlled before-after studies, interrupted time series, and quasi-experimental studies. We screened in duplicate, then extracted data and appraised risk of bias in duplicate with a pre-tested form. We conducted random-effects meta-analysis and Bayesian network meta-analysis. FINDINGS: We included 52 studies of duration 5 years or less with 1 108 541 children, and four long-term studies 8-10 years after mass deworming programmes with more than 160 000 children. Overall risk of bias was moderate. Mass deworming for soil-transmitted helminths compared with controls led to little to no improvement in weight over a period of about 12 months (0·99 kg, 95% credible interval [CrI] -0·09 to 0·28; moderate certainty evidence) or height (0·07 cm, 95% CrI -0·10 to 0·24; moderate certainty evidence), little to no difference in proportion stunted (eight fewer per 1000 children, 95% CrI -48 to 32; high certainty evidence), cognition measured by short-term attention (-0·23 points on a 100 point scale, 95% CI -0·56 to 0·14; high certainty evidence), school attendance (1% higher, 95% CI -1 to 3; high certainty evidence), or mortality (one fewer per 1000 children, 95% CI -3 to 1; high certainty evidence). We found no data on quality of life and little evidence of adverse effects. Mass deworming for schistosomiasis might slightly increase weight (0·41 kg, 95% CrI -0·20 to 0·91) and has little to no effect on height (low certainty evidence) and cognition (moderate certainty evidence). Our analyses do not suggest indirect benefits for untreated children from being exposed to treated children in the community. We are uncertain about effects on long-term economic productivity (hours worked), cognition, literacy, and school enrolment owing to very low certainty evidence. Results were consistent across sensitivity and subgroup analyses by age, worm prevalence, baseline nutritional status, infection status, impact on worms, infection intensity, types of worms (ascaris, hookworm, or trichuris), risk of bias, cluster versus individual trials, compliance, and attrition. INTERPRETATION: Mass deworming for soil-transmitted helminths with or without deworming for schistosomiasis had little effect. For schistosomiasis, mass deworming might be effective for weight but is probably ineffective for height, cognition, and attendance. Future research should assess which subset of children do benefit from mass deworming, if any, using individual participant data meta-analysis. FUNDING: Canadian Institutes of Health Research and WHO.
BACKGROUND: Soil-transmitted helminthiasis and schistosomiasis, considered among the neglected tropical diseases by WHO, affect more than a third of the world's population, with varying intensity of infection. We aimed to evaluate the effects of mass deworming for soil-transmitted helminths (with or without deworming for schistosomiasis or co-interventions) on growth, educational achievement, cognition, school attendance, quality of life, and adverse effects in children in endemic helminth areas. METHODS: We searched 11 databases up to Jan 14, 2016, websites and trial registers, contacted authors, and reviewed reference lists. We included studies published in any language of children aged 6 months to 16 years, with mass deworming for soil-transmitted helminths or schistosomiasis (alone or in combination with other interventions) for 4 months or longer, that reported the primary outcomes of interest. We included randomised and quasi-randomised trials, controlled before-after studies, interrupted time series, and quasi-experimental studies. We screened in duplicate, then extracted data and appraised risk of bias in duplicate with a pre-tested form. We conducted random-effects meta-analysis and Bayesian network meta-analysis. FINDINGS: We included 52 studies of duration 5 years or less with 1 108 541 children, and four long-term studies 8-10 years after mass deworming programmes with more than 160 000 children. Overall risk of bias was moderate. Mass deworming for soil-transmitted helminths compared with controls led to little to no improvement in weight over a period of about 12 months (0·99 kg, 95% credible interval [CrI] -0·09 to 0·28; moderate certainty evidence) or height (0·07 cm, 95% CrI -0·10 to 0·24; moderate certainty evidence), little to no difference in proportion stunted (eight fewer per 1000 children, 95% CrI -48 to 32; high certainty evidence), cognition measured by short-term attention (-0·23 points on a 100 point scale, 95% CI -0·56 to 0·14; high certainty evidence), school attendance (1% higher, 95% CI -1 to 3; high certainty evidence), or mortality (one fewer per 1000 children, 95% CI -3 to 1; high certainty evidence). We found no data on quality of life and little evidence of adverse effects. Mass deworming for schistosomiasis might slightly increase weight (0·41 kg, 95% CrI -0·20 to 0·91) and has little to no effect on height (low certainty evidence) and cognition (moderate certainty evidence). Our analyses do not suggest indirect benefits for untreated children from being exposed to treated children in the community. We are uncertain about effects on long-term economic productivity (hours worked), cognition, literacy, and school enrolment owing to very low certainty evidence. Results were consistent across sensitivity and subgroup analyses by age, worm prevalence, baseline nutritional status, infection status, impact on worms, infection intensity, types of worms (ascaris, hookworm, or trichuris), risk of bias, cluster versus individual trials, compliance, and attrition. INTERPRETATION: Mass deworming for soil-transmitted helminths with or without deworming for schistosomiasis had little effect. For schistosomiasis, mass deworming might be effective for weight but is probably ineffective for height, cognition, and attendance. Future research should assess which subset of children do benefit from mass deworming, if any, using individual participant data meta-analysis. FUNDING: Canadian Institutes of Health Research and WHO.
Authors: L Arnoldo Muñoz-Nevárez; Brandon M Imp; Michael A Eller; Francis Kiweewa; Jonah Maswai; Christina Polyak; Omalla Allan Olwenyi; I Elaine Allen; Eric Rono; Benedetta Milanini; Hannah Kibuuka; Julie A Ake; Leigh Anne Eller; Victor G Valcour Journal: J Neurovirol Date: 2019-08-29 Impact factor: 2.643
Authors: Vivian Andrea Welch; Alomgir Hossain; Elizabeth Ghogomu; Alison Riddle; Simon Cousens; Michelle Gaffey; Paul Arora; Robert Black; Donald Bundy; Mary Christine Castro; Li Chen; Omar Dewidar; Alison Elliott; Henrik Friis; T Déirdre Hollingsworth; Sue Horton; Charles H King; Huong Le Thi; Chengfang Liu; Fabian Rohner; Emily K Rousham; Rehana Salam; Erliyani Sartono; Peter Steinmann; Taniawati Supali; Peter Tugwell; Emily Webb; Franck Wieringa; Pattanee Winnichagoon; Maria Yazdanbakhsh; Zulfiqar A Bhutta; George A Wells Journal: J Dev Effect Date: 2019-12-06
Authors: Nathan C Lo; David G Addiss; Peter J Hotez; Charles H King; J Russell Stothard; Darin S Evans; Daniel G Colley; William Lin; Jean T Coulibaly; Amaya L Bustinduy; Giovanna Raso; Eran Bendavid; Isaac I Bogoch; Alan Fenwick; Lorenzo Savioli; David Molyneux; Jürg Utzinger; Jason R Andrews Journal: Lancet Infect Dis Date: 2016-11-30 Impact factor: 25.071
Authors: Kathryn J Else; Jennifer Keiser; Celia V Holland; Richard K Grencis; David B Sattelle; Ricardo T Fujiwara; Lilian L Bueno; Samuel O Asaolu; Oluyomi A Sowemimo; Philip J Cooper Journal: Nat Rev Dis Primers Date: 2020-05-28 Impact factor: 52.329