Global distribution of outbreaks of water-associated infectious diseases

Background: water plays an important role in the transmission of many infectious diseases,which pose a great burden on global public health. however,the global distribution of these water-associated infectious diseases and underlying factors remain largely unexplored. methods and findings: based on the global infectious disease and epidemiology network (gideon),a global database including water-associated pathogens and diseases was developed. in this study,reported outbreak events associated with corresponding water-associated infectious diseases from 1991 to 2008 were extracted from the database. the location of each reported outbreak event was identified and geocoded into a gis database. also collected in the gis database included geo-referenced socio-environmental information including population density (2000),annual accumulated temperature,surface water area,and average annual precipitation. poisson models with bayesian inference were developed to explore the association between these socio-environmental factors and distribution of the reported outbreak events. based on model predictions a global relative risk map was generated. a total of 1,428 reported outbreak events were retrieved from the database. the analysis suggested that outbreaks of water-associated diseases are significantly correlated with socio-environmental factors. population density is a significant risk factor for all categories of reported outbreaks of water-associated diseases; water-related diseases (e.g.,vector-borne diseases) are associated with accumulated temperature; water-washed diseases (e.g.,conjunctivitis) are inversely related to surface water area; both water-borne and water-related diseases are inversely related to average annual rainfall. based on the model predictions,hotspots of risks for all categories of water-associated diseases were explored. conclusions: at the global scale,water-associated infectious diseases are significantly correlated with socio-environmental factors,impacting all regions which are affected disproportionately by different categories of water-associated infectious diseases. © 2012 yang et al.