A multi-level approach for investigating socio-economic and agricultural risk factors associated with rates of reported cases of Escherichia coli O157 in humans in Alberta, Canada.
Using negative binomial and multi-level Poisson models, the authors determined the statistical significance of agricultural and socio-economic risk factors for rates of reported disease associated with Escherichia coli O157 in census subdivisions (CSDs) in Alberta, Canada, 2000-2002. Variables relating to population stability, aboriginal composition of the CSDs, and the economic relationship between CSDs and urban centres were significant risk factors. The percentage of individuals living in low-income households was not a statistically significant risk factor for rates of disease. The statistical significance of cattle density, recorded at a higher geographical level, depended on the method used to correct for overdispersion, the number of levels included in the multi-level models, and the choice of using all reported cases or only sporadic cases. Our results highlight the importance of local socio-economic risk factors in determining rates of disease associated with E. coli O157, but their relationship with individual risk factors requires further evaluation.
Pearl
D L
DL
Department of Population Medicine, University of Guelph, Guelph, ON, Canada. dpearl@uoguelph.ca
Louie
M
M
Chui
L
L
Doré
K
K
Grimsrud
K M
KM
Martin
S W
SW
Michel
P
P
Svenson
L W
LW
McEwen
S A
SA
D000416:Alberta / Q000453:epidemiology; D000818:Animals; D002417:Cattle; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D019453:Escherichia coli O157; D006801:Humans; D015994:Incidence; D008954:Models, Biological; D016273:Occupational Exposure; D012307:Risk Factors; D012959:Socioeconomic Factors; D015047:Zoonoses