RESUMEN
BACKGROUND: A team of experts of the Faculty of Medicine, Addis Ababa University reported the emergence of unidentified fatal liver disease in Tahtay Koraro Woreda, Tigray in the mid of December 2005. The EHNRI has been then instructed to investigate the possible etiological agent that are likely to be responsible in triggering the health problem and a field survey team consisting of experts were went to the affected area to investigate the situations surrounding the disease. OBJECTIVES: This investigation was conducted to determine the possible etiological agent(s) for the stated health problem in the affected village. METHOD: Acute toxicity study was performed on animal model for the various samples used in human consumption, which was followed by histopathological examination of the liver of the sacrificed laboratory animals. In order to facilitate the elucidation of the causative agent for the alleged health problem further tests for clinical markers and antigens were also performed on the serum collected from affected persons. RESULT: Neither death nor toxic symptoms manifestations were observed on laboratory animals when feeding the consumable samples for a period of two weeks, however histopathological examination of the liver of the sacrificed animals that were given the unprotected pond water and Tela samples from the affected village as a drink revealed severe hepatoic necrosis. Biochemical test results of the serum samples revealed raised level of some clinical markers that are highly significant for detecting liver abnormality of toxic origin. Serological test for surface antigen ruled out the possible causes of infectious origin such as viral hepatitis. CONCLUSION: The overall results confirmed that the causative agent for the outbreak of the liver disease was of toxic origin rather than due to infectious agent and this was found to be associated with consumption of contaminated water as well as Tela.