Determinants of epidemiologic transition in rural Africa: the role of socioeconomic status and drinking water source.

Background: Many African countries experience a protracted epidemiologic transition, different from the classical transition in western societies. The factors driving this protracted transition are largely unknown. In northeast Ghana, we studied an ongoing epidemiologic transition and investigated the effects of socioeconomic status and drinking water source on the transition.

Methods: During a 9-year period, we followed a cohort of almost 30 000 individuals and collected information on mortality and fertility rates. In addition, using the standards set out by the WHO, we obtained the causes of death by verbal autopsy. Individuals were stratified according to their socioeconomic status and the households' use of an improved or unimproved drinking water source.

Results: Mortality rates decreased by -5.0% annually (p<0.001) and the main cause of death shifted from infectious to non-infectious diseases (p=0.014). General fertility rates and child-women ratios decreased annually by -12.7% (p<0.001) and -11.9% (p<0.001), respectively. There was no difference in the decline of mortality and fertility depending on socioeconomic status or drinking water source.

Conclusions: Factors other than socioeconomic status and drinking water source are responsible for the observed declines in mortality and fertility observed during the protracted epidemiologic transition. Identifying the specific determinants of the ongoing transition is of importance, as they could be targeted in order to further improve public health in rural African countries.