Case-control study of an acute aflatoxicosis outbreak, Kenya, 2004

Environ Health Perspect. 2005 Dec;113(12):1779-83. doi: 10.1289/ehp.8384.


Objectives: During January-June 2004, an aflatoxicosis outbreak in eastern Kenya resulted in 317 cases and 125 deaths. We conducted a case-control study to identify risk factors for contamination of implicated maize and, for the first time, quantitated biomarkers associated with acute aflatoxicosis.

Design: We administered questionnaires regarding maize storage and consumption and obtained maize and blood samples from participants.

Participants: We recruited 40 case-patients with aflatoxicosis and 80 randomly selected controls to participate in this study.

Evaluations/measurements: We analyzed maize for total aflatoxins and serum for aflatoxin B1-lysine albumin adducts and hepatitis B surface antigen. We used regression and survival analyses to explore the relationship between aflatoxins, maize consumption, hepatitis B surface antigen, and case status.

Results: Homegrown (not commercial) maize kernels from case households had higher concentrations of aflatoxins than did kernels from control households [geometric mean (GM) = 354.53 ppb vs. 44.14 ppb; p = 0.04]. Serum adduct concentrations were associated with time from jaundice to death [adjusted hazard ratio = 1.3; 95% confidence interval (CI), 1.04-1.6]. Case patients had positive hepatitis B titers [odds ratio (OR) = 9.8; 95% CI, 1.5-63.1] more often than controls. Case patients stored wet maize (OR = 3.5; 95% CI, 1.2-10.3) inside their homes (OR = 12.0; 95% CI, 1.5-95.7) rather than in granaries more often than did controls.

Conclusion: Aflatoxin concentrations in maize, serum aflatoxin B1-lysine adduct concentrations, and positive hepatitis B surface antigen titers were all associated with case status.

Relevance: The novel methods and risk factors described may help health officials prevent future outbreaks of aflatoxicosis.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aflatoxins / analysis*
  • Aflatoxins / poisoning
  • Aged
  • Case-Control Studies
  • Child
  • Child, Preschool
  • DNA Adducts / blood
  • Disease Outbreaks*
  • Female
  • Food Contamination / analysis*
  • Food Handling / statistics & numerical data
  • Foodborne Diseases / epidemiology*
  • Hepatitis B Surface Antigens / blood
  • Humans
  • Infant
  • Kenya / epidemiology
  • Male
  • Middle Aged
  • Regression Analysis
  • Risk Assessment
  • Surveys and Questionnaires
  • Survival Analysis
  • Zea mays / chemistry*


  • Aflatoxins
  • DNA Adducts
  • Hepatitis B Surface Antigens