A study of potential climate risk factors of enteric waterborne disease in southern Alberta & Ontario

Current Global Climate Models indicate that global climates will change significantly in the near future. The models/scenarios suggest that Canada could experience warmer winters, longer and drier summers and the potential for an increase in the quantity and severity of extreme weather events. A shift in Canadian climate could represent an increase and redistribution of the spatial and temporal risk associated with enteric waterborne disease. This study attempts to quantify the present comparative risk of enteric waterborne disease for Southern Alberta using a case control study of hospitalization data, agricultural and land use indices, water source and treatment information as well as observed and interpolated climate data. Initial investigation considers hospitalization discharge data for 18 census subdivisions in Southern Alberta from 1992 through 1998. Agricultural and land use indices include livestock density and primary vegetation qualifiers, as obtained from the 1996 Alberta Agriculture Census and the Global Land Cover 2000 project respectively. Various interpolation techniques are used to obtain point specific climate information for all case and control locations. Logistic models of enteric waterborne disease risk for Southern Alberta considering the effect of spatial and temporal factors are described. Ontario data is used to validate the Alberta analysis as well as providing a useful comparison for the same time period. The resulting models from Alberta and Ontario are used to determine the potential changes to risk of enteric waterborne illness for various future climate scenarios and extreme weather events.