title: An outbreak of liver disease in Tahtay Koraro Woreda, Tigray region of Ethiopia: a case-control study for the identification of the etiologic agent.
abstract: BACKGROUND
  An outbreak of fatal liver disease of unidentified origin in Tahtay Koraro Woreda, Tigray Region was reported at the end of 2005. In response to this report, a team of investigators was deployed from the EHNRI to assess the situation in the affected area.
  
  
  OBJECTIVE
  The objective of the trip was to investigate the probable etiological agent(s) for the stated health problem and to suggest possible means of containing the outbreak.
  
  
  METHODS
  A case-control epidemiological method was employed in collecting information from the affected (case) area and a non-affected adjacent area (control) using structured questionnaire. Qualitative data was also collected through focus group discussion (FGD) at community as well as woreda level. Samples of biological and environmental nature were also collected from both case and control areas for a subsequent laboratory analysis in order to identify the causative agent of the outbreak.
  
  
  RESULTS
  The comparative analysis of the various variables and possible exposure factors between the two sites (case vs control village) revealed that both villages were similar in terms of their exposure to most of the suspected factors including exposure to chemicals, food storage and handling practices, and to the use of traditional herbal medicines or consumption of wild edible plants. However, it was observed that the residents in the affected site (over 96%) relied more on unprotected or protected well as a source of drinking water and other household purposes while most in the non-affected depended on fresh water from river or unprotected spring. This difference was significant, p = 0.000 (OR = 840, 95% CI = 50.1, 14095.7).
  
  
  CONCLUSIONS
  Though several of the possible exposure factors to the epidemic appear to be similar for both the case and control villages, the water source they use for drinking and other household purposes differed markedly. It therefore seems plausible that the problem in the case area could be linked to this water source.
authors.affiliation: Ethiopian Health and Nutrition Research Institute, Addis Ababa, Ethiopia, P. O. Box 1242, Addis Ababa, Ethiopia.
authors.forename: Dawit
authors.initials: D
authors.lastname: Abebe
authors.forename: Asfaw
authors.initials: A
authors.lastname: Debella
authors.forename: Frew
authors.initials: F
authors.lastname: Tekabe
authors.forename: Yared
authors.initials: Y
authors.lastname: Mekonnen
authors.forename: Ambaye
authors.initials: A
authors.lastname: Degefa
authors.forename: Asnakech
authors.initials: A
authors.lastname: Mekonnen
authors.forename: Alemtsehaye
authors.initials: A
authors.lastname: Tefera
authors.forename: Hailu
authors.initials: H
authors.lastname: Mamo
authors.forename: Bekure
authors.initials: B
authors.lastname: Tsegaye
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000706:statistics & numerical data; D060766:Drinking Water; D004781:Environmental Exposure / Q000009:adverse effects; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D017144:Focus Groups; D006801:Humans; D008107:Liver Diseases / Q000209:etiology* / Q000401:mortality; D008297:Male; D012424:Rural Population; D014876:Water Pollution / Q000009:adverse effects; D055815:Young Adult
chemical_list: D060766:Drinking Water