Potential relations between acute lower respiratory infections and weather conditions in Benin

Acute respiratory infections (ARI) are the leading cause of death among children under 5 worldwide. It is established that the respiratory system is sensitive to changes in atmospheric conditions but few studies have focused on the relation between ARI and weather conditions, especially in sub-Saharan Africa. Associations between monthly rates of acute lower respiratory infections (ALRI) in children under 5 in four health zones in Benin (West Africa) and several weather factors (temperature, relative humidity and rainfall) were calculated with Pearson correlation coefficients. In addition, the ALRI occurrences in the dry and rainy seasons were characterized by five indicators for each year from 1998 through 2008. Associations between interannual variability of these indicators and weather factors were determined with Spearman correlation tests. Only in February were results similar in all health areas, with dry and cold conditions associated with increases in ALRI rates. The marked character of the dry season was accompanied by higher ALRI rates in the southern part of the study area, where the dry season is shorter than the wet season. Conversely, the strong character of the wet season is associated with higher ALRI rates in the wet season in the North, where the rainy season is shorter than the dry season. These results contribute to a better understanding of the spatial and temporal variability of ALRI for children under 5 in rural areas of Benin and may help predict its occurrence.