An analysis of antibiotic prescribing practices for enteric bacterial infections within FoodNet Canada sentinel sites.

OBJECTIVES: Understanding the current state of antibiotic treatment guidelines and prescribing practices for bacterial enteric infections is critical to inform antibiotic stewardship initiatives. This study aims to add to the current understanding through three objectives: (i) to identify and summarize published treatment guidelines for bacterial enteric infections; (ii) to describe observed antibiotic prescribing practices for bacterial enteric infections across three sentinel sites in Canada; and (iii) to assess concordance between observed antibiotic prescribing and treatment guidelines. METHODS: An environmental scan of treatment guidelines for bacterial enteric infections was conducted and recommendations were collated. A descriptive analysis of cases of bacterial enteric illnesses captured in FoodNet Canada's sentinel site surveillance system between 2010 and 2018 was performed. Antibiotic-use data were self-reported by cases via an enhanced questionnaire. RESULTS: Ten treatment guidelines were identified in the environmental scan. There was substantial variation between guidelines for both when to prescribe antibiotics and which antibiotics were recommended. Of the 5877 cases of laboratory-confirmed bacterial enteric illness in the three sites, 49% of cases reported having received an antibiotic prescription. Of particular significance was the finding that 21% of verotoxigenic Escherichia coli cases received a prescription. Of the 17 antibiotics recommended in the guidelines, 14 were used in practice. In addition to these, 18 other antibiotics not included in any of the guidelines reviewed were also prescribed. CONCLUSIONS: Our study suggests that a substantial proportion of enteric bacterial infections in Canada are prescribed antibiotics. These findings highlight the need to standardize treatment guidelines for enteric illnesses and could be used to inform future stewardship programme development.

Outbreak of Escherichia coli 0157:H7 related to animal contact at a petting zoo.

OBJECTIVE: To determine the cause of an outbreak of Escherichia coli 0157:H7 related to animal exposures so that further transmission could be prevented. DESIGN: Description of laboratory investigations and a case control study. SETTING: Agricultural pavilion at an annual fair in Ontario. POPULATION: People with laboratory evidence of E coli 0157:H7 (seven people) and others with diarrhea (155 people) who called the health unit following a media release were interviewed. Animals that were accessed most frequently by the public in the agriculture pavilion were tested for E coli 0157:H7. In the case control study, a case was defined as someone with laboratory confirmed E coli 0157:H7, or someone who developed severe or bloody diarrhea two to eight days after attending the agricultural pavilion at the fair (61 people). A convenience sample of people who attended the agricultural pavilion but did not develop diarrhea was selected as the control group (89 people). INTERVENTIONS: Human and animal E coli 0157:H7 specimens were subtyped. Cases and controls were interviewed using a standardized questionnaire. RESULTS: Subtyping of the seven human isolates of E coli 0157:H7 revealed five that were of an extremely uncommon phage type. Three samples from goats and one from sheep at the petting zoo in the agricultural pavilion were of this same phage type. The case control study also implicated goats (odds ratio [OR] 3.65; 95% CI 1.63 to 8.52) and sheep (OR 2.94; 95% CI 1.33 to 6.57) from the petting zoo. CONCLUSIONS: Results of this investigation suggest strongly that the goats and sheep from the petting zoo were the source of this outbreak of E coli 0157:H7.