title: Monitoring the impact of a national school based deworming programme on soil-transmitted helminths in Kenya: the first three years, 2012 - 2014.
abstract: In 2012, the Kenyan Ministries of Health and of Education began a programme to deworm all school-age children living in areas at high risk of soil-transmitted helminths (STH) and schistosome infections. The impact of this school-based mass drug administration (MDA) programme in Kenya is monitored by the Kenya Medical Research Institute (KEMRI) as part of a five-year (2012-2017) study. This article focuses on the impact of MDA on STH infections and presents the overall achieved reductions from baseline to mid-term, as well as yearly patterns of reductions and subsequent re-infections per school community.
  
  
  
  The study involved a series of pre- and post-intervention, repeat cross-sectional surveys in a representative, stratified, two-stage sample of schools across Kenya. The programme contained two tiers of monitoring; a national baseline and mid-term survey including 200 schools, and surveys conducted among 60 schools pre- and post-intervention. Stool samples were collected from randomly selected school children and tested for helminth infections using Kato-Katz technique. The prevalence and mean intensity of each helminth species were calculated at the school and county levels and 95 % confidence intervals (CIs) were obtained by binomial and negative binomial regression, respectively, taking into account clustering by schools.
  
  
  
  The overall prevalence of STH infection at baseline was 32.3 % (hookworms: 15.4 %; Ascaris lumbricoides: 18.1 %; and Trichuris trichiura: 6.7 %). After two rounds of MDA, the overall prevalence of STH had reduced to 16.4 % (hookworms: 2.3 %; A. lumbricoides: 11.9 %; and T. trichiura: 4.5 %). The relative reductions of moderate to heavy intensity of infections were 33.7 % (STH combined), 77.3 % (hookworms) and 33.9 % (A. lumbricoides). For T. trichiura, however, moderate to heavy intensity of infections increased non-significantly by 18.0 % from baseline to mid-term survey.
  
  
  
  The school-based deworming programme has substantially reduced STH infections, but because of ongoing transmission additional strategies may be required to achieve a sustained interruption of transmission.
authors.affiliation: Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya. comondi@kemri.org.
authors.forename: Collins
authors.initials: C
authors.lastname: Okoyo
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
authors.forename: Birgit
authors.initials: B
authors.lastname: Nikolay
authors.affiliation: Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Kihara
authors.affiliation: Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.
authors.forename: Elses
authors.initials: E
authors.lastname: Simiyu
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Joshua V
authors.initials: JV
authors.lastname: Garn
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Mathew C
authors.initials: MC
authors.lastname: Freeman
authors.affiliation: Division of Vector-borne and Neglected Tropical Diseases, Ministry of Public Health and Sanitation, Nairobi, P.O. Box 19982-00202, Kenya.
authors.forename: Mariam T
authors.initials: MT
authors.lastname: Mwanje
authors.affiliation: Division of Vector-borne and Neglected Tropical Diseases, Ministry of Public Health and Sanitation, Nairobi, P.O. Box 19982-00202, Kenya.
authors.forename: Dunstan A
authors.initials: DA
authors.lastname: Mukoko
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Brooker
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Pullan
authors.affiliation: Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.
authors.forename: Sammy M
authors.initials: SM
authors.lastname: Njenga
authors.affiliation: Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Mwandawiro
mesh_terms: D000293:Adolescent; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006373:Helminthiasis / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission; D006376:Helminths / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012574:Schools / Q000706:statistics & numerical data; D012987:Soil / Q000469:parasitology*; D055815:Young Adult
chemical_list: D000871:Anthelmintics; D012987:Soil
keywords: Ascaris lumbricoides; Hookworms; School-based deworming; Trichuris trichiura