The implications of epidemiologic transition in sub-Saharan Africa
Chinelo Enwonwu looks at the epidemiologic transmission of chronic diseases in developing countries, particularly in Nigeria
In these past decades, there has been a rapid growth in overall health, social, and economic development. There has also been a marked decrease in infectious diseases and a trend towards chronic and degenerative diseases as outlined in the recent Lancet series on Chronic diseases. One of the historic processes of change that describes these changes is the theory of “epidemiologic transition” first proposed by Omran. (1) The “epidemiologic transition” is a concept that describes the shifting patterns of nutrition and health indicators in the human history. It is divided into four sequential stages: pestilence and famine, receding pandemics, degenerative and man-made diseases, and delayed degenerative diseases.
The epidemiologic transition is a framework that helps to better understand the distribution of disease across the globe. Sub-Saharan Africa (SSA) is greatly affected by stage 1 of this transition, whereas developed countries experience a higher burden of non-communicable chronic diseases (NCDs). However, with rapid urbanization in many parts of SSA, there is evidence that this transition to a greater burden of chronic diseases is occurring in Africa. (2)
The prevalence of NCDs still remains higher in developed countries, but the patterns of their rise in developing countries are becoming evident and are expected to increase with the aging of the population. Following the patterns of the epidemiologic transition, the progression from one stage to the next tends to proceed in a predictable manner. (3) In other words, the patterns of emergence of chronic diseases in developing countries are expected to be similar to what has already happened in the developed world. While it took a longer period of time for developed countries to move from a time of infectious diseases to their current state of high prevalence of NCDs, the timeframe for the transition in the developing world will be compressed. (3)
Many developed countries may be entering a fifth unnamed phase of the epidemiologic transition (3) but some of the developing world, especially SSA, are caught in between two or more stages. WHO has conducted studies such as the Global Burden of Disease study (GBD), which have helped elucidate the epidemiology and trends of NCDs in developing regions of the world. This study suggests that by 2020, the proportion of the overall burden in sub-Saharan Africa due to NCDs will increase to somewhere between 26% and 34% . (4) But chronic diseases have not simply displaced acute infectious diseases in developing countries. Rather such countries now experience what is called a polarized and protracted “double burden of disease.” (5)
Nigeria is an example of the SSA countries where the double burden of disease is evident. This is manifested in the increasing prevalence of lifestyle diseases like diabetes, and of overweight and obese individuals, as well as the dominance of infectious diseases. Many countries in Africa continue to deal with issues such as immunization, eradication of infectious diseases, and problems of HIV; NCDs such as diabetes, stroke, and hypertension are also public health issues to be addressed. According to the WHO report on chronic diseases, communicable diseases, maternal and perinatal conditions, and nutritional deficiencies will still be the leading causes of death in Nigeria in 2015 but deaths from chronic diseases are not far behind. (6) In essence, chronic diseases have not displaced acute and infectious diseases; rather there is an ongoing double burden of disease in such countries. The Nigerian Federal Ministry of Health has recognized the increasing prevalence of chronic diseases in the country and now has as part of its vision “to reverse the increasing prevalence of non-communicable diseases.” (7)
In summary, chronic diseases have an impact on the health of the population, and if they continue to be ignored, huge consequences will result. There is a need to tackle the issue of the duality of disease burden in SSA. First, chronic diseases need to be placed higher on the political agenda. Its exclusion from the Millennium Development Goals (MDGs) is already an impediment to addressing the problem in places like SSA, which are the main targets of the MDGs. Because chronic diseases affect all parts of economic development, it cannot be excluded from initiatives, goals, and policies, intended to improve economic development. Secondly, risk factors for NCDs need to be controlled in SSA. One major risk factor is the lack of education about NCDs, appropriate lifestyle habits, and preventative methods, to mention but a few. The role of health educators and healthcare providers need to accommodate educating individuals on these issues. The last but not the least, the health care system in SSA is already strained dealing with just infectious diseases, talk less of handling a double burden of disease. Therefore, there should be an increased focus on NCD prevention methods like exercising, eating healthy diets, and reducing tobacco intake. Also the health systems in SSA need to be realigned to include NCD planning and program implementation.
Chinelo Enwonwu
MPH Graduate
Case Western Reserve University
Cleveland
Ohio
USA
chinelo.enwonwu@case.edu
(1) Popkin, B. (1993) “Nutritional Patterns and Transitions.” Population and Development Review vol. 19 no. 1, pp. 138-157
(2) Tucker, K.L & Buranapin, S. (2001) “Nutrition and Aging in Developing Countries.” Journal of Nutrition vol. 131, pp. 2417S-2423S
(3) Popkin, B. (2001) “The Nutrition Transition and Obesity in the Developing World.” Journal of Nutrition vol. 131, pp. 871S-873S
(4) Unwin, N; Setel, P; Rashid, S; Mugusi, F; Mbanya, J; Kitange, H; Hayes, L; Edwards, R; Aspray, T& Alberti, K (2001) “Non-communicable diseases in sub-Saharan Africa: where do they feature in the health research agenda?” Bulletin of the World Health Organization vol. 79, no. 10, pp. 947-953
(5) Yach, D; Hawkes, C; Gould, C. & Hofman, K. (2004) “The Global Burden of Chronic Diseases - Overcoming Impediments to Prevention and Control.” JAMA vol. 29, no. 21, pp. 2616-2622
(6) World Health Organization (2005) Preventing Chronic Disease: A Vital Investment. World Health Organization. Geneva, Switzerland
(7) Federal Ministry of Health, Nigeria. Available on: http://www.nigeria.gov.ng/fed_min_health.aspx
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