2.3.6 Morbidity, Mortality and the Epidemiological Transition

Facts/messages: The demographic transition is accompanied by an epidemiological transition which goes hand-in-hand with the emergence of chronic-degenerative diseases that mainly affect adults and older adults, groups that are increasingly numerous in the population while it advances in the demographic transition. These diseases are related to new life styles that are a reflection of modern life, as well as deaths and disabilities caused by violence that primarily affect men and young adults, especially the poor and, in some countries, certain ethnic or cultural groups. In countries at intermediate levels of development, these chronic-degenerative diseases should be added to the infectious-contagious diseases that predominated in the past and that have not been adequately controlled, so that on the whole they are characterized by a mixed health pattern.

Methodology: Display death rates by causes and rates of incidence and/or prevalence of the most common illnesses in the population. Make use of indicators on the use of health services. Show the evolution of the country’s epidemiological situation, with particular reference to the evolution of infectious-contagious versus degenerative diseases. Depending on the situation in the country, it may be appropriate to pay special attention to violence and accidents and to self-inflicted morbidity (e.g. associated with alcoholism) and mortality. In countries with peculiar mortality patterns by sex (e.g. excess female mortality in South-Central Asia and excess male mortality in Eastern Europe), one may either choose to comment on these patterns here or postpone this discussion to Chapter IV.

For projection purposes, one may use projections for the incidence of morbidity due to different causes in each sex and age group and combine these with population projections to derive projections of the global incidence of different pathologies. The Disability Adjusted Life Years (DALY) methodology used by WHO can be useful in this context, although one should be careful in interpreting these indicators, which have been criticized on the grounds that they attach insufficient importance to the social cost of pathologies associated with sexual and reproductive health.

Primary Sources:

  • Health ministry web pages and publications;
  • National epidemiological surveillance systems;
  • Censuses;
  • Health surveys.

Secondary Sources:


  • African Development Bank and UNFPA (2005). Training Module on Integration of Population Issues into African Development Bank programmes and projects. Module 2, Session 1 on Levels and trends in Population Size, Fertility, Mortality and Migration.