title: Comprehensive assessment of maize aflatoxin levels in Eastern Kenya, 2005-2007.
abstract: BACKGROUND
  Aflatoxin, a potent fungal toxin, contaminates 25% of crops worldwide. Since 2004, 477 aflatoxin poisonings associated with eating contaminated maize have been documented in Eastern Kenya, with a case-fatality rate of 40%.
  
  
  OBJECTIVE
  We characterized maize aflatoxin contamination during the high-risk season (April-June) after the major harvests in 2005, 2006 (aflatoxicosis outbreak years), and 2007 (a non-outbreak year).
  
  
  METHODS
  Households were randomly selected each year from the region in Kenya where outbreaks have consistently occurred. At each household, we obtained at least one maize sample (n = 716) for aflatoxin analysis using immunoaffinity methods and administered a questionnaire to determine the source (i.e., homegrown, purchased, or relief) and amount of maize in the household.
  
  
  RESULTS
  During the years of outbreaks in 2005 and 2006, 41% and 51% of maize samples, respectively, had aflatoxin levels above the Kenyan regulatory limit of 20 ppb in grains that were for human consumption. In 2007 (non-outbreak year), 16% of samples were above the 20-ppb limit. In addition, geometric mean (GM) aflatoxin levels were significantly higher in 2005 (GM = 12.92, maximum = 48,000 ppb) and 2006 (GM = 26.03, maximum = 24,400 ppb) compared with 2007 (GM = 1.95, maximum = 2,500 ppb) (p-value < 0.001). In all 3 years combined, maize aflatoxin levels were significantly higher in homegrown maize (GM = 17.96) when compared with purchased maize (GM = 3.64) or relief maize (GM = 0.73) (p-value < 0.0001).
  
  
  CONCLUSIONS
  Aflatoxin contamination is extreme within this region, and homegrown maize is the primary source of contamination. Prevention measures should focus on reducing homegrown maize contamination at the household level to avert future outbreaks.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. bez2@cdc.gov
authors.forename: Johnni H
authors.initials: JH
authors.lastname: Daniel
authors.forename: Lauren W
authors.initials: LW
authors.lastname: Lewis
authors.forename: Yanique A
authors.initials: YA
authors.lastname: Redwood
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kieszak
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
authors.forename: W Dana
authors.initials: WD
authors.lastname: Flanders
authors.forename: Carlos
authors.initials: C
authors.lastname: Bell
authors.forename: John
authors.initials: J
authors.lastname: Mwihia
authors.forename: George
authors.initials: G
authors.lastname: Ogana
authors.forename: Sopiato
authors.initials: S
authors.lastname: Likimani
authors.forename: Masja
authors.initials: M
authors.lastname: Straetemans
authors.forename: Michael A
authors.initials: MA
authors.lastname: McGeehin
mesh_terms: D000348:Aflatoxins / Q000032:analysis*; D001230:Aspergillus / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005470:Fluorometry; D005506:Food Contamination / Q000032:analysis* / Q000706:statistics & numerical data; D005517:Foodborne Diseases / Q000453:epidemiology*; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D057230:Limit of Detection; D011795:Surveys and Questionnaires; D003313:Zea mays / Q000737:chemistry* / Q000382:microbiology; D000096702:Aflatoxin Poisoning
chemical_list: D000348:Aflatoxins