a1 Mount Sinai Hospital, Toronto, ON, Canada
a2 University of Toronto, Toronto, ON, Canada
a3 Children's Hospital of Western Ontario, London, ON, Canada
a4 The University of Western Ontario, London, ON, Canada
a5 University of Calgary, Calgary, AB, Canada
a6 University of Alberta, Edmonton, AB, Canada
a7 Alberta Health Services, Edmonton, AB, Canada
a8 St Joseph's Health Care, London, ON, Canada
a9 University of Guelph, Guelph, ON, Canada
a10 Ontario Agency for Health Protection and Promotion, Toronto, ON, Canada
To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005–2006 were asked to participate in a cross-sectional study. Household members aged ≥12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.
(Accepted May 11 2011)
(Online publication June 23 2011)
† The ARO Water Study Group are listed in the Appendix.