Changes in climate that lead to an increase in temperature and a decrease in precipitation are associated with an increase in diarrheal disease in children in Botswana, a sub-Saharan country with distinct wet and dry seasons (Alexander KA et al. Int J Environ Res Public Health. 2013;10:1202-1230).
Because previous studies have indicated that diarrheal disease rates could be altered by changes in climate, US investigators evaluated monthly reports of diarrheal disease among patients in Botswana who visited health facilities between 1974 and 2003 and compared these data with climatic variables such as rainfall, minimum temperature, and vapor pressure during this time period. The incidence of diarrhea peaked in both the wet and dry seasons but unexpectedly was highest in the dry season, with a 20% increase over the yearly mean. The authors hypothesize that the hot, dry conditions may increase the activity and density of flies that transmit diarrhea-causing microorganisms.
Friedrich MJ. Climate Change Linked With Increase in Diarrheal Disease. JAMA. 2013;309(19):1985. doi:10.1001/jama.2013.5879