title: Unprogrammed deworming in the Kibera slum, Nairobi: implications for control of soil-transmitted helminthiases.
abstract: BACKGROUND
  Programs for control of soil-transmitted helminth (STH) infections are increasingly evaluating national mass drug administration (MDA) interventions. However, "unprogrammed deworming" (receipt of deworming drugs outside of nationally-run STH control programs) occurs frequently. Failure to account for these activities may compromise evaluations of MDA effectiveness.
  
  
  METHODS
  We used a cross-sectional study design to evaluate STH infection and unprogrammed deworming among infants (aged 6-11 months), preschool-aged children (PSAC, aged 1-4 years), and school-aged children (SAC, aged 5-14 years) in Kibera, Kenya, an informal settlement not currently receiving nationally-run MDA for STH. STH infection was assessed by triplicate Kato-Katz. We asked heads of households with randomly-selected children about past-year receipt and source(s) of deworming drugs. Local non-governmental organizations (NGOs) and school staff participating in school-based deworming were interviewed to collect information on drug coverage.
  
  
  RESULTS
  Of 679 children (18 infants, 184 PSAC, and 477 SAC) evaluated, 377 (55%) reported receiving at least one unprogrammed deworming treatment during the past year. PSAC primarily received treatments from chemists (48.3%) or healthcare centers (37.7%); SAC most commonly received treatments at school (55.0%). Four NGOs reported past-year deworming activities at 47 of >150 schools attended by children in our study area. Past-year deworming was negatively associated with any-STH infection (34.8% vs 45.4%, p = 0.005). SAC whose most recent deworming medication was sourced from a chemist were more often infected with Trichuris (38.0%) than those who received their most recent treatment from a health center (17.3%) or school (23.1%) (p = 0.05).
  
  
  CONCLUSIONS
  Unprogrammed deworming was received by more than half of children in our study area, from multiple sources. Both individual-level treatment and unprogrammed preventive chemotherapy may serve an important public health function, particularly in the absence of programmed deworming; however, they may also lead to an overestimation of programmed MDA effectiveness. A standardized, validated tool is needed to assess unprogrammed deworming.
authors.affiliation: Parasitic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Julie R
authors.initials: JR
authors.lastname: Harris
authors.affiliation: Parasitic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Caitlin M
authors.initials: CM
authors.lastname: Worrell
authors.affiliation: Division of Global HIV/AIDS, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Davis
authors.affiliation: Kenya Medical Research Institute, Centre for Global Health Research, Nairobi, Kenya.
authors.forename: Kennedy
authors.initials: K
authors.lastname: Odero
authors.affiliation: Kenya Medical Research Institute, Centre for Global Health Research, Nairobi, Kenya.
authors.forename: Ondari D
authors.initials: OD
authors.lastname: Mogeni
authors.affiliation: Parasitic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Deming
authors.affiliation: Public Health Department, School Health Program, Nairobi County, Nairobi, Kenya.
authors.forename: Aden
authors.initials: A
authors.lastname: Mohammed
authors.affiliation: Division of Global Health Protection, Centers for Disease Control and Prevention, Nairobi, Kenya.
authors.forename: Joel M
authors.initials: JM
authors.lastname: Montgomery
authors.affiliation: Kenya Medical Research Institute, Centre for Global Health Research, Nairobi, Kenya; Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Sammy M
authors.initials: SM
authors.lastname: Njenga
authors.affiliation: Parasitic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: LeAnne M
authors.initials: LM
authors.lastname: Fox
authors.affiliation: Children Without Worms, Task Force for Global Health, Decatur, Georgia, United States of America.
authors.forename: David G
authors.initials: DG
authors.lastname: Addiss
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006373:Helminthiasis / Q000188:drug therapy / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D007630:Kenya; D008297:Male; D012987:Soil / Q000469:parasitology*
chemical_list: D012987:Soil