Sharp decline of diarrhea hospitalizations despite historical drought in Brazil: The potential role of local water supply and public health measures.

Severe droughts (SDs) present a risk to public health, particularly in terms of the proliferation of waterborne diseases, such as diarrhea. Because of climate change, the frequency of SDs is likely to increase, potentially straining traditional water supply systems. An 11-year period of SDs in Northeast Brazil, which commenced in 2012, reduced the capacity of 153 drinking water reservoirs to a mere 6.7%, with 86% of water bodies exhibiting eutrophic characteristics. During this period, several water supply and public health measures were implemented. Those measures were associated with a reduction in the incidence of diarrhea hospitalizations during the entire SD period, with an average annual reduction of -4.9%. This assessment identifies potential adaptive measures to mitigate the impact of climate change on water-related human health, thus supporting the implementation of measures to protect against climate risks to public health.