An outbreak of liver disease in Tahtay Koraro Woreda, Tigray region of Ethiopia: a case-control study for the identification of the etiologic agent.

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. OBJECTIVES: 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. METHOD: 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. RESULT: 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). CONCLUSION: 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.

Physico-chemical investigation of consumables and environmental samples to determine the causative agent of liver disease outbreak in Tahitay Koraro Woreda, Tigray.

BACKGROUND: The occurrence of liver disease out break of unknown origin and of a significant morbidity and mortality with a major symptom of abdominal dropsy was reported among the inhabitants of Tsaeda--Emba village, Tahtay Koraro woreda, Tigray during mid December, 2005. OBJECTIVES: The aim of this study was to assess if chemical intoxicants were the responsible agents for the outbreak in the affected locality. METHODS: The experimental approach towards the identification of the possible causative agent from the consumables and environmental samples collected from the affected village were determination of physico-chemical quality parameters and chemical analysis using instrumental and chromatographic techniques. RESULTS: The intoxicant was found to stem from the consumption of the water from the unprotected well in which pyrrolizidine containing plant, Ageratum sp, abundantly thrives. CONCLUSION: The water source was intimately linked to the outbreak of disease and, therefore, immediate intervention and preventive measures are called for.

Toxicity study and evaluation of biochemical markers towards the identification of the causative agent for an outbreak of liver disease in Tahtay Koraro Woreda, Tigray.

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.