Interrupting transmission of soil-transmitted helminths: a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya.
BACKGROUND
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
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.


BACKGROUND
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.


BACKGROUND
NCT02397772.
Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
Simon J
SJ
Brooker
Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
Charles S
CS
Mwandawiro
Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
Katherine E
KE
Halliday
Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
Sammy M
SM
Njenga
Evidence Action, Nairobi, Kenya.
Carlos
C
Mcharo
Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
Paul M
PM
Gichuki
Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
Beatrice
B
Wasunna
Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
Jimmy H
JH
Kihara
Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
Doris
D
Njomo
Neglected Tropical Diseases Unit, Division of Communicable Disease Prevention and Control, Ministry of Health, Nairobi, Kenya.
Dorcas
D
Alusala
Office of the Executive Committee, Medical Services and Public Health, Kwale County Government, Kwale, Kenya.
Athuman
A
Chiguzo
Faculty 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.
Hugo C
HC
Turner
Evidence Action, Nairobi, Kenya.
Caroline
C
Teti
Evidence Action, Nairobi, Kenya.
Claire
C
Gwayi-Chore
Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
Birgit
B
Nikolay
Faculty 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.
James E
JE
Truscott
Warwick Mathematics Institute, University of Warwick, Coventry, UK School of Life Sciences, University of Warwick, Coventry, UK.
T Déirdre
TD
Hollingsworth
Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, UK.
Dina
D
Balabanova
Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, UK.
Ulla K
UK
Griffiths
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Matthew C
MC
Freeman
Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Elizabeth
E
Allen
Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
Rachel L
RL
Pullan
Faculty 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.
Roy M
RM
Anderson
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015766:Albendazole / Q000008:administration & dosage*; D000871:Anthelmintics / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control / Q000379:methods*; D003362:Cost-Benefit Analysis; D003430:Cross-Sectional Studies; D005260:Female; D006725:Hookworm Infections / Q000188:drug therapy* / Q000453:epidemiology*; D006801:Humans; D007630:Kenya; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011634:Public Health; D012107:Research Design; D012111:Residence Characteristics; D012574:Schools; D012987:Soil / Q000469:parasitology*; D011795:Surveys and Questionnaires; D055815:Young Adult
D000871:Anthelmintics; D012987:Soil; D015766:Albendazole
EPIDEMIOLOGY; PARASITOLOGY; PUBLIC HEALTH