Rick McGeer Distinguished Technologist HP Enterprise Services.
Brenda L. Coleman, Allison McGeer, Marina Salvadori, Ian Johnson, Iris Gutmanis,
description
Transcript of Brenda L. Coleman, Allison McGeer, Marina Salvadori, Ian Johnson, Iris Gutmanis,
The role of drinking water as a source of transmission of
antimicrobial resistant Escherichia coli
Brenda L. Coleman, Allison McGeer, Marina Salvadori, Ian Johnson, Iris Gutmanis,
Sue Bondy, Norm Neuman, Marie Louis,Scott McEwen, Fran Jamieson, & Rebecca Irwin
Antimicrobial Resistance
• What is it?
• Why do we care?
• How does it occur?– Selective pressure– Transmission
Escherichia coli
• Human colonization
• Human infection
• Water as a vehicle for transmission
• E. coli indicator of contamination
Private drinking water
• 10-50% of Canadian households
• 30-50% test water
• 2-20% contaminated with E. coli
Objectives
1. Measure the proportion of E. coli positive water samples that are antimicrobial resistant (AR)
2. Measure the prevalence of human carriage of AR E. coli
3. Determine whether the use of water contaminated with AR E. coli is associated with human carriage
SamplingPublic health labs
(Water samples)
Standard testing for bacterial contaminationat participating laboratories
E. coli - positiveNo bacterial
contamination
Surveillance(Water samples)
E. coli susceptibility tested sample
Resistant Susceptible
Case-control(Households)
Eligible & non-replicate householdsHousehold questionnaire
Case Control A Control B
Cross-sectional(Individuals)
Eligible individualsPersonal questionnaire & rectal swab
Resistant Susceptible
Water samples
340,009 tested
15,238 E. coli (4.5%)
6,492 susceptibility tested
645 resistant (9.9%)
Proportion of E. coli positive water samples that were antimicrobial resistantOntario May 2005-September 2006
0%
2%
4%
6%
8%
10%
12%
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Proportion of E. coli- positive water samples and proportion of antimicrobial resistant E. coli- positive isolates
Ontario, May 1, 2005 - September 30, 2006
0%
5%
10%
15%
20%
25%
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E. coli
Resistant
Human samples1,710 households eligible
↓
831 household questionnaires
↓
655 households →985 personal
questionnaires
↓
488 households ← 699 rectal swabs
Households & Subjects
488 households• 108 with AR E. coli water source
– 69 with untreated AR E. coli
699 subjects• 12 to 87 years old• Males = females• 433 (62%) used tap water only• 376 (54%) travelled outside Canada• 185 (27%) had direct livestock contact• 85 (12%) used antibiotic
Proportion of rectal swabs with AR E. coliOntario, 2005-2007
0%
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20%
30%
40%
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Theorized relationship between human carriage & consumption of antimicrobial
resistant E. coliPotential effect modifier:
Bottled water
Primary predictor: Outcome:
Water used Carriage of antimicrobial resistant E. coli
Potential confounders:
Age Antibiotic use
Sex Hospitalization
Household education Child in day care
Household income Household size
Laboratory region Contact with livestock
Mode of data collection Farming property
Days between water sample Contact with dog/cat
& interview Contact with raw meatTravel
Final multivariable model
Predictor RR 95% Conf. interval
Water used (contaminated & not treated) 1.4 1.1, 1.7
Travel outside Canada 1.3 1.1, 1.6
Contact with cattle 1.3 1.0, 1.5
Sex (male) 1.2 1.0, 1.5
Limitations
• Convenience sample
• Age of subjects
• Lack of exposure dose/treatment of water
• Causation
Conclusions
• Private drinking water sources are contaminated with AR E. coli
• Relatively high prevalence of AR E. coli carriage in non-institutionalized residents
• Carriage of AR E. coli is associated with the use of contaminated water