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Interrupting transmission of soil-transmitted helminths: a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya
  1. Simon J Brooker1,
  2. Charles S Mwandawiro2,
  3. Katherine E Halliday1,
  4. Sammy M Njenga2,
  5. Carlos Mcharo3,
  6. Paul M Gichuki2,
  7. Beatrice Wasunna2,
  8. Jimmy H Kihara2,
  9. Doris Njomo2,
  10. Dorcas Alusala4,
  11. Athuman Chiguzo5,
  12. Hugo C Turner6,
  13. Caroline Teti3,
  14. Claire Gwayi-Chore3,
  15. Birgit Nikolay1,
  16. James E Truscott6,
  17. T Déirdre Hollingsworth7,8,
  18. Dina Balabanova9,
  19. Ulla K Griffiths9,
  20. Matthew C Freeman10,
  21. Elizabeth Allen11,
  22. Rachel L Pullan1,
  23. Roy M Anderson6
  1. 1Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
  2. 2Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
  3. 3Evidence Action, Nairobi, Kenya
  4. 4Neglected Tropical Diseases Unit, Division of Communicable Disease Prevention and Control, Ministry of Health, Nairobi, Kenya
  5. 5Office of the Executive Committee, Medical Services and Public Health, Kwale County Government, Kwale, Kenya
  6. 6Faculty of Medicine, Department of Infectious Disease Epidemiology, London Centre for Neglected Tropical Disease Research, School of Public Health, St Mary's Campus, Imperial College London, London, UK
  7. 7Warwick Mathematics Institute, University of Warwick, Coventry, UK
  8. 8School of Life Sciences, University of Warwick, Coventry, UK
  9. 9Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, UK
  10. 10Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
  11. 11Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
  1. Correspondence to Dr Rachel Pullan; rachel.pullan{at}


Introduction In recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but mathematical modelling has shown that in all but very low transmission settings, SBD is unlikely to interrupt transmission, and that new treatment strategies are required. This study seeks to answer the question: is it possible to interrupt the transmission of STH, and, if so, what is the most cost-effective treatment strategy and delivery system to achieve this goal?

Methods and analysis Two cluster randomised trials are being implemented in contrasting settings in Kenya. The interventions are annual mass anthelmintic treatment delivered to preschool- and school-aged children, as part of a national SBD programme, or to entire communities, delivered by community health workers. Allocation to study group is by cluster, using predefined units used in public health provision—termed community units (CUs). CUs are randomised to one of three groups: receiving either (1) annual SBD; (2) annual community-based deworming (CBD); or (3) biannual CBD. The primary outcome measure is the prevalence of hookworm infection, assessed by four cross-sectional surveys. Secondary outcomes are prevalence of Ascaris lumbricoides and Trichuris trichiura, intensity of species infections and treatment coverage. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, worm burden and proportion of unfertilised eggs will be assessed longitudinally. A nested process evaluation, using semistructured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system.

Ethics and dissemination Study protocols have been reviewed and approved by the ethics committees of the Kenya Medical Research Institute and National Ethics Review Committee, and London School of Hygiene and Tropical Medicine. The study has a dedicated web site.

Trial registration number NCT02397772.


This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See:

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