How does climate contribute to intra-annual variability and abnormal peaks of acute respiratory infections among children in rural Benin?

Florence De Longueville, Facultés Universitaires Notre-Dame de la Paix, Belgium
Sabine J. F. Henry, Facultés Universitaires Notre-Dame de la Paix, Belgium

Today, no doubt remains on the existence of effects – mostly negative – of natural environment on human health. Acute respiratory infections (ARI) alone account for more than 20% of the causes of child mortality in the world. The international scientific literature dealing with environmental impacts on ARI is very scarce, particularly in West Africa. This communication aims first to highlight the intra-annual variability of lower ARI affecting children in rural Benin according to a north-south gradient. The second objective is to detect abnormal peaks of ARI in time or/and in space and to assess the potential contribution of extreme weather conditions on these extreme ARI rates. Spectral analysis on time-series data and statistical tests on binary variables are used. We show that the intra-annual variability of ARI depends on latitude and seems to be in narrow relation with the climatic zone. The dry season seems to have only an impact on ARI incidences in the northern part of the study area. On the other hand, ARI incidences peak at the end of the rainy season(s) in the whole study area. During some months over the study period (1998-2006), ARI rate values deviate from the average and we suppose that these abnormal peaks can be partially explained by climate influences. This study is important for a better understanding of the impacts of environmental factors on health in West Africa. Moreover, in the context of climate changes, it is expected that more extreme climatic events will happen in the future. This study can contribute to evaluate the effects of extreme weather conditions on ARI incidences. This can be useful for the planning of public health activities.