The principles of epidemiologic transition and the experiences in Kenya

Abstract

Background Throughout history, man has ignited dynamic changes in his ecosystem. In a cascading and feedback manner, these changes have, in return, significantly impacted on his probability of survival by exerting critical pressures that have shaped the population sizes, life styles, life expectancy and disease status. This position has been compounded further by climatic changes which have arisen as a consequence of man's activities that have disturbed the ecosystem balance. In deliberate efforts to place adequate food on the table, man has embarked on extensive land use thereby encroaching on new habitats and interrupting biodiversity balance. Within these new habitats, he has encountered new disease pathogens with expected consequences of wide oscillations in mortality rates. Migration as a result of conflicts, poverty, search for pastures and other forces have also thrown a critical spanner in these dynamics. In addition, the speed of mobility has become a key cog wheel in the process of change; in the 18th century, it took an average of six months to travel from one continent to another while today one can traverse three continents in twenty four hours. Industrialization coupled by global, regional and local socio -economic adjustments has also become a major pillar in the superstructure of these changes while government policies have had their influences on functionality of health systems. The ultimate consequence of these changes on health has been one of definite transitions across phases of disease scenarios over time at both local and global levels. Phases of pestilence, receding pandemics and upsurge of chronic diseases have become evident at varying levels in different countries. Objectives The main objective of this review is to demonstrate from literature the underlying principles of epidemiologic transition and to highlight the experiences in Kenya. Methodology Review literature from different countries including whatever is available in Kenya. Expected output To prepare a firm ground for a concept note aimed at conducting a comprehensive study of the scenario in Kenya. Armed with such information, the health system will be better placed to predict the next scenario to enable proactive preparation. Results Medical and public health factors still lag behind in many African countries Kenya included. We are however aware of the influence they have early in the accelerated and contemporary epidemiologic transitions. The mortality decline currently being experienced in developing countries has been more recent and the effect of medical factors has been more direct and more salient. In the African countries and in Kenya in particular, the tremendous impact of imported medical technologies on mortality has been magnified by massive public health programs. This is slowly leading to the transition from predominantly infectious diseases to chronic degenerative diseases.