IMPACT OF CLIMATE AND AGRICULTURE ON ENTERIC ILLNESS IN ATLANTIC CANADA: IMPLICATIONS OF CLIMATE CHANGE

Abstract

ISEE-252 Introduction: The University of Guelph, the Public Health Agency of Canada and Environment Canada are working together on a national project investigating the incidence of enteric illness in Canada, describing the complex relationships between disease incidence and weather parameters, water quality and quantity, and the potential impact that global climate change will have on these parameters. Several case studies have been identified to examine the relationship between reported waterborne disease and weather events. This project will describe temporal and spatial trends in cases of enteric illness in Atlantic Canada and examine the relationship between weather parameters (temperature and precipitation) and the incidence of enteric illness in Atlantic Canada accounting for temporal and spatial clustering. This information will then be used to evaluate the potential impact that climate change will have on the incidence of enteric illness in this region. Methods: Disease data were extracted from the Canadian Institute for Health Information Discharge Abstract Database for the time period 1992–1998. Cases were classified as acute gastroenteritis using ICD9 codes. Agricultural indicators were derived from the 1996 Canadian Census of Agriculture and combined with remotely sensed land use data to get a more accurate estimate of where agricultural practices impact the surrounding environment. Daily weather values for precipitation and temperature were obtained from the Meteorological Service of Canada. Spatial and temporal trends were examined for the study period. Interpolation methods will be used to transform disease rates into smoothed rates over the province to facilitate analysis at a finer geographical resolution. Associations between acute gastroenteritis, agricultural indicators and weather parameters will be examined using a random effects modelling framework. Results: Preliminary results showed a seasonal pattern that peaked in spring to early summer for all provinces. Spatial patterns of disease incidence in one province indicated a south to north increase in disease rates when expressed at a watershed level, however this trend disappeared when rates were expressed using a community level political boundary. Further analysis will examine the association between disease incidence, agricultural intensity and weather parameters (such as the previous week's precipitation level). It is hoped that examining data at the weekly level will give a clearer picture of role that weather and agriculture play in disease transmission since the disease events occur on a relatively fine time scale. Climate change scenarios will be applied to the findings to better understand of how global climate change may affect the risk of enteric illness in Atlantic Canada. Discussion: The results of these studies will help identify geographic areas and populations vulnerable to an increased risk of enteric illness. These studies will allow Canadian policy makers to better understand and manage current risks of waterborne enteric illness, and to devise strategies to adapt to an uncertain climatic future and the potential for more extreme weather events.