RESUMO
BACKGROUND: An outbreak of an unidentified cause of liver disease that claimed the lives of more than 45 people occurred in a rural community, in Northwestern Tigray. Despite the wider need for an urgent response there was no obvious explanation for the disease occurrence. OBJECTIVE: The aim of the study was to collect basic descriptive information and compare exposure status among case and control house-holds to better understand the illness and its pattern of occurrence so as to identify the sources, mode of transmission and possible cause of the illness. METHODS: The initial study principally involved combination of descriptive and analytic study designs. Combinations of quantitative and qualitative data were collected using semi-structured questionnaires. STUDY SUBJECTS: Samples of the affected and non-affected individuals of study village, key informants from various levels in the administrative system, and focus group discussions organized from both the affected and non-affected households of the study village were the subjects included for the study. RESULTS: The outbreak involved about 118 people, (78 males and 40 females) who were residents of the same village, in most, members of same family. More than half of the cases were under the age of 15 years. The outstanding clinical features were abdominal pain, rapidly filling ascites and hepatomegaly. The median duration of illness was six months (range; 1, 36 months). Of the 118 cases, 45 were deaths reported from the same community, during the period of illness with an estimated case fatality rate of 38%. Of the 45 deaths, 64.4% were children below 15 years of age. Qualitative information from both case and control communities showed difference in their water source. Eighty four percent of the dwellers in the affected village of Tsaeda Amba fetch water for their drink from an open shallow unprotected pond, Mai Habi-Tselam, Analysis of the data on exposure to the risk factor (case--control house-holds) revealed that users of the Habi-Tselam water source were almost 3 times more likely to develop the liver disease than those who used other water sources in the same village, OR = 3.14, 95% CI: 3.14 (3.12, 3.23). Age, nutritional status and long duration of exposure to an implicated source tended to influence the prognosis. CONCLUSION: The initial epidemiological investigations therefore gave an important insight as to the need to conduct further possible in-depth etiologic investigations, including clinical and toxicological studies, Study recommended an intermediary control measures including: banning the use of the implicated water source and provision of save and alternative potable water to the affected community.