The impact of livestock farming on the incidence of human Shiga toxin-producing Escherichia coli (STEC) infection was assessed by using several livestock density indicators (LDI) that were generated in a systematic approach. A total of 80 LDI were considered suitable proxy measures for livestock density. Multivariate Poisson regression identified several LDI as having a significant spatial association with the incidence of human STEC infection. The strongest associations with human STEC infection were the ratio of beef cattle number to human population and the application of manure to the surface of agricultural land by a solid spreader and by a liquid spreader. This study demonstrates the value of using a systematic approach in identifying LDI and other spatial predictors of disease.
To assess provincial-level predictors among socioeconomic and influenza rate data for the use of different macrolide antimicrobials in Canada from 2000 to 2006.
Multivariable models were developed to describe macrolide defined daily doses per capita.
Use was highest during October to March for all macrolides. Investigated yearly and provincial patterns differed considerably among the macrolide agents. Associations with socioeconomic variables were similar between clarithromycin and erythromycin, while azithromycin consumption showed some differences in its association with these variables. Consistently, the rate of influenza was significantly associated with increased macrolide use. The influenza rate interacted with socioeconomic variables in some models; as the influenza rate increased, the greatest increase in demand for macrolides occurred in populations with high percentages of low-income individuals, high unemployment levels and low percentages of individuals with bachelor's degrees.
The impact of associations among macrolide consumption, influenza and socioeconomic factors may reflect inappropriate use of these agents to treat viral infections and/or prescribing for secondary infections, and knowledge of the virus versus bacteria problem and accessibility of healthcare. Further research surrounding differences in access to antimicrobial prescriptions and treatment options between advantaged and disadvantaged populations is suggested to further understand the dynamics of antimicrobial use in Canada.
To assess potential risk factors among socioeconomic variables and the rate of influenza for the use of different fluoroquinolone antimicrobials in Canada, and to evaluate modelling fluoroquinolone-use data by two different outcome measures.
Fluoroquinolone use was described monthly from 2000 to 2006 by two outcome measurements: defined daily doses and prescription counts. Multivariable linear and negative binomial models were produced with socioeconomic and influenza rate data.
Significant socioeconomic predictors varied among the individual fluoroquinolone models, which may reflect the range of infections that are treated with fluoroquinolones. However, socioeconomic variables within the ciprofloxacin and levofloxacin models were similar, and indicated that use was highest in advantaged populations, depending on the measures being assessed. The rate of influenza was a significant predictor within models describing levofloxacin use and the defined daily dose model for ciprofloxacin use, after accounting for season. Influenza significantly interacted with the education variable in the levofloxacin defined daily dose model.
Significant associations between levofloxacin use and influenza rates, after accounting for season, may suggest that levofloxacin was used to treat secondary bacterial infections or was prescribed inappropriately for seasonal viral respiratory tract infections. Yearly patterns of ciprofloxacin use show that prescribing practices changed; more ciprofloxacin prescriptions were dispensed towards the end of the study period, but for smaller doses or shorter treatment times. Associations with socioeconomic variables suggest that the fluoroquinolones ciprofloxacin and levofloxacin were more likely to be used in advantaged populations, probably due to the high cost of fluoroquinolone antimicrobials in comparison to the penicillin and macrolide groups.
The study objectives were to identify potential associations between reported antimicrobial use (AMU) practices and antimicrobial resistance (AMR) of fecal and environmental Salmonella spp. isolates (n = 322 isolates) recovered from 60 Alberta finishing swine farms, and to estimate the amount of pen and farm level variation in AMR. The AMU data were collected through a questionnaire. Separate multilevel logistic regression models were built for six antimicrobials with prevalence of resistance >or=5% using the Generalized Linear Latent and Mixed Model (GLLAMM) procedure. In-feed use of tylosin in finishers was associated with increased odds of resistance in Salmonella isolates to ampicillin (OR = 61.56), streptomycin (OR = 11.70), and multiple antimicrobials (OR = 4.90). Injectable penicillin use in growers was associated with decreased odds of resistance in Salmonella isolates to streptomycin (OR = 0.06), kanamycin (OR = 0.03), and multiple antimicrobials (OR = 0.12). Injectable penicillin use in finishers was associated with decreased odds of resistance in Salmonella isolates to ampicillin (OR = 0.007) and chloramphenicol (OR = 0.04). Overall, these results indicate that AMU in pig production is inconsistently associated with AMR in Salmonella from finishing swine. Variation in AMR prevalence of Salmonella isolates of swine was moderate to high at pen and farm levels for most antimicrobials suggesting that interventions at the pen and farm levels might be beneficial in reducing the emergence of AMR Salmonella in swine populations.
Enteric illness associated with foodborne and waterborne disease is thought to be common in some Canadian Indigenous communities. This study aimed to understand the lived experience of acute gastrointestinal illness (AGI), including symptoms and severity, perceived causes, and healthcare seeking behaviors of AGI in the small Inuit community of Rigolet, Canada. A concurrent mixed quantitative and qualitative methods design was used. Two cross-sectional retrospective surveys provided quantitative data to examine self-reported AGI symptoms and the distribution of potential risk factors in the community. Qualitative data from in-depth interviews with one-third of AGI cases were analyzed using a constant-comparative method to describe symptoms and severity, identify perceived risk factors, and explore health seeking behavior of AGI in Rigolet. Of the survey respondents reporting AGI, most reported symptoms of diarrhea without vomiting, followed by diarrhea with vomiting, and vomiting without diarrhea. The most common secondary symptoms included stomach cramps and abdominal pain, nausea, and extreme tiredness. Community members identified potential risk factors for AGI that reflect the epidemiology triad (host, agent, and environmental factors), including hygiene, retail food, tap water, boil water advisories, and personal stress. Risk aversion and healthcare seeking behaviors reflected the core constructs of the Health Belief Model (perceived susceptibility, severity, and benefits and barriers to action). Understanding community experience, perspectives, and beliefs related to AGI is useful for public health practitioners and health care providers. This information is important especially considering the relatively high estimated burden of AGI and the relatively low healthcare seeking behaviors in some Indigenous communities compared to national estimates. Moreover, the mixed-methods approach used to understand the burden of AGI could be extended to other health research in Indigenous contexts.
Climate change is expected to cause changes in precipitation quantity, intensity, frequency and duration, which will subsequently alter environmental conditions and might increase the risk of waterborne disease. The objective of this study was to describe the seasonality of and explore associations between weather, water quality and occurrence of infectious gastrointestinal illnesses (IGI) in two communities in Nunatsiavut, Canada. Weather data were obtained from meteorological stations in Nain (2005-2008) and Rigolet (2008). Free-chlorine residual levels in drinking water were extracted from municipal records (2005-2008). Raw surface water was tested weekly for total coliform and E. coli counts. Daily counts of IGI-related clinic visits were obtained from health clinic registries (2005-2008). Analysis of weather and health variables included seasonal-trend decomposition procedures based on Loess. Multivariable zero-inflated Poisson regression was used to examine potential associations between weather events (considering 0-4 week lag periods) and IGI-related clinic visits. In Nain, water volume input (rainfall + snowmelt) peaked in spring and summer and was positively associated with levels of raw water bacteriological variables. The number of IGI-related clinic visits peaked in the summer and fall months. Significant positive associations were observed between high levels of water volume input 2 and 4 weeks prior, and IGI-related clinic visits (P
This study estimated the prevalence of Campylobacter, Salmonella, and Escherichia coli isolated from fresh retail turkey purchased at grocery stores in Ontario, Canada. The antimicrobial susceptibility patterns were determined and assessed for potential public health risk. From February 2003 to May 2004, 465 raw turkey meat samples were collected. Antimicrobial susceptibility testing was performed for Campylobacter isolates with a concentration gradient test and for Salmonella and E. coli isolates with a broth microdilution assay. Campylobacter isolates were recovered from 188 (46%) of 412 samples. The prevalence of resistance to one or more antimicrobials was 168 (81%) of 208. For antimicrobials of very high human health importance (category I of Health Canada's antimicrobial categorization), 12 (6%) of 208 Campylobacter isolates were ciprofloxacin resistant. Salmonella isolates were recovered from 95 (24%) of 397 samples. The prevalence of resistance to one or more antimicrobials was 50 (49%) of 102, and 13 (13%) of 102 samples were resistant to five or more antimicrobials. For category I antimicrobials, 14 (14%) of 102 and 1 (1%) of 102 isolates were resistant to ceftiofur and ceftriaxone, respectively. E. coli isolates were recovered from 392 (95%) of 412 turkey samples. The prevalence of resistance to one or more antimicrobials was 906 (71%) of 1,281, and 225 (18%) of 1,281 samples were resistant to five or more antimicrobials. For category I antimicrobials, 30 (2%) of 1,281 samples were resistant to ceftiofur. This study demonstrated that raw turkey pieces are a potential source of human exposure to enteric pathogens, including antimicrobial-resistant bacteria, if undercooked or improperly handled.
Provincial broiler-chicken marketing boards in Canada have recently implemented an on-farm food safety program called Safe, Safer, Safest. The purpose of this study was to measure broiler chicken producers' attitudes toward the program and food safety topics and use of highly recommended good production practices (GPP). Mailed and Web-based questionnaires were administered to all producers registered in British Columbia, Ontario, and Quebec in 2008. The response percentage was 33.2% (642 of 1,932). Nearly 70% of respondents rated the program as effective in producing safe chicken, and 49.1% rated the program requirements as easy to implement. Most respondents (92.9%) reported that they do not raise other poultry or keep birds as pets, and 79.8% reported that they clean and disinfect their barns between each flock cycle. Less than 50% of respondents reported that visitors wash their hands or change their clothes before entering barns, 38.4% reported that catching crews wear clean clothes and boots, and 35.8% reported that a crew other than from the hatchery places chicks. Respondents who rated the program requirements as effective or easy to implement were more likely to report the use of five of six highly recommended GPP. Only 21.1% of respondents indicated that Campylobacter can be transmitted from contaminated chicken meat to humans, and 26.6% believed that antimicrobial use in their industry is linked to antimicrobial resistance in humans. Continuing education of producers should focus on improving their awareness of these issues, while mandatory GPP should include those that are known to be effective in controlling Campylobacter and Salmonella in broiler chicken flocks.
This exploratory study used participatory methods to identify, characterize, and rank climate-sensitive health priorities in Nunatsiavut, Labrador, Canada.
A mixed method study design was used and involved collecting both qualitative and quantitative data at regional, community, and individual levels. In-depth interviews with regional health representatives were conducted throughout Nunatsiavut (n?=?11). In addition, three PhotoVoice workshops were held with Rigolet community members (n?=?11), where participants took photos of areas, items, or concepts that expressed how climate change is impacting their health. The workshop groups shared their photographs, discussed the stories and messages behind them, and then grouped photos into re-occurring themes. Two community surveys were administered in Rigolet to capture data on observed climatic and environmental changes in the area, and perceived impacts on health, wellbeing, and lifestyles (n?=?187).
Climate-sensitive health pathways were described in terms of inter-relationships between environmental and social determinants of Inuit health. The climate-sensitive health priorities for the region included food security, water security, mental health and wellbeing, new hazards and safety concerns, and health services and delivery.
The results highlight several climate-sensitive health priorities that are specific to the Nunatsiavut region, and suggest approaching health research and adaptation planning from an EcoHealth perspective.
This study estimated the prevalence of Salmonella, Campylobacter, and Escherichia coli isolates in fresh retail grain-fed veal obtained in Ontario, Canada. The prevalence and antimicrobial resistance patterns were examined for points of public health significance. Veal samples (n = 528) were collected from February 2003 through May 2004. Twenty-one Salmonella isolates were recovered from 18 (4%) of 438 samples and underwent antimicrobial susceptibility testing. Resistance to one or more antimicrobials was found in 6 (29%) of 21 Salmonella isolates; 5 (24%) of 21 isolates were resistant to five or more antimicrobials. No resistance to antimicrobials of very high human health importance was observed. Ampicillin-chloramphenicolstreptomycin-sulfamethoxazole-tetracycline resistance was found in 5 (3%) of 21 Salmonella isolates. Campylobacter isolates were recovered from 5 (1%) of 438 samples; 6 isolates underwent antimicrobial susceptibility testing. Resistance to one or more antimicrobials was documented in 3 (50%) of 6 Campylobacter isolates. No Campylobacter isolates were resistant to five or more antimicrobials or category I antimicrobials. E. coli isolates were recovered from 387 (88%) of 438 samples; 1,258 isolates underwent antimicrobial susceptibility testing. Resistance to one or more antimicrobials was found in 678 (54%) of 1,258 E. coli isolates; 128 (10%) of 1,258 were resistant to five or more antimicrobials. Five (0.4%) and 7 (0.6%) of 1,258 E. coli isolates were resistant to ceftiofur and ceftriaxone, respectively, while 34 (3%) of 1,258 were resistant to nalidixic acid. Ciprofloxacin resistance was not detected. There were 101 different resistance patterns observed among E. coli isolates; resistance to tetracycline alone (12.7%, 161 of 1,258) was most frequently observed. This study provides baseline prevalence and antimicrobial resistance data and highlights potential public health concerns.