A rural Ethiopian population undergoing epidemiological transition over a generation:: Butajira from 1987 to 2004

Aims: To describe the epidemiological development of a rural Ethiopian population from 1987 to 2004 in terms of mortality and associated sociodemographic factors. Methods: A rural population comprising 10 communities was defined in 1987 and has since been followed by means of regular household visits. After an initial census, births, deaths and migration events were recorded, together with key background factors, on an open cohort basis. Over 97,000 individuals were observed during a total of over 700,000 person years. Results: The initial population of 28,614 increased by an average of 3.64% annually to 54,426 from 1987 to 2004, and also grew older on average. Birth and mortality rates fell, but were still subject to short-term variation due to external factors. Overall mortality was 13.5 per 1000 person years. Increasing mortality in some adult age groups was consistent with increasing AIDS-related deaths, but a new local hospital in 2002 may have contributed to later falls in overall mortality. Sex, age group, time period, literacy, water source, house ownership and distance to town were all significantly associated with mortality differentials. Conclusions: This population has undergone a complex epidemiological transition during a generation. Detailed long-term surveillance of this kind is essential for describing such processes. Many factors that significantly affect mortality cannot be directly controlled by the health sector and will only improve with general development.