SARS-CoV-2 outbreak in a Canadian suburban tertiary hospital necessitating full facility closure: a descriptive observational study.

BACKGROUND: SARS-CoV-2 can cause outbreaks in community- and hospital-based settings. The aim of this study was to provide a detailed epidemiologic account of a hospital-wide SARS-CoV-2 outbreak and provide a description of case evaluations, transmission networks and the interventions implemented to stem the outbreak. METHODS: We conducted a retrospective descriptive study of a hospital-wide SARS-CoV-2 outbreak at the Misericordia Community Hospital (Edmonton) from June 21 to Aug. 14, 2020. We reviewed hospital chart, public health and occupational health records to determine demographics, case type (community- or hospital-acquired), need for critical care and outcome for each case linked to the outbreak (patients, hospital staff, and community and patient visitors). We developed detailed transmission networks using epidemiologic data to determine what variables may have contributed to transmission. RESULTS: Fifty-eight cases of SARS-CoV-2 infection were linked to this hospital outbreak (31 patients, 25 staff members and 2 visitors; 66% female, age range 19-97 years). One patient required critical care, and 11 deaths were recorded (all among inpatients). Most cases were hospital-acquired (91%), and 28% were asymptomatic at the time of diagnosis. The outbreak was composed of 2 clusters driven by protective equipment breaches, premature removal of precautions, transmission in small staff quarters and infection of a staff member after exposure to a wandering patient with dementia and asymptomatic, undetected SARS-CoV-2 infection. INTERPRETATION: A detailed epidemiologic review of this hospital-wide outbreak shows that a SARS-CoV-2 outbreak can involve complex transmission chains and clusters. Multipronged bundled approaches, aggressive contact tracing, and patient and staff prevalence screening are important to help bring such outbreaks under control, along with ongoing vigilance in detecting delayed cases.

A comparison of surgical site infections following total hip replacement and total knee replacement surgeries identified by Infection Prevention and Control and the National Surgical Quality Improvement Program in Alberta, Canada.

OBJECTIVE: To understand how the different data collections methods of the Alberta Health Services Infection Prevention and Control Program (IPC) and the National Surgical Quality Improvement Program (NSQIP) are affecting reported rates of surgical site infections (SSIs) following total hip replacements (THRs) and total knee replacements (TKRs). DESIGN: Retrospective cohort study. SETTING: Four hospitals in Alberta, Canada. PATIENTS: Those with THR or TKR surgeries between September 1, 2015, and March 31, 2018. METHODS: Demographic information, complex SSIs reported by IPC and NSQIP were compared and then IPC and NSQIP data were matched with percent agreement and Cohen's κ calculated. Statistical analysis was performed for age, gender and complex SSIs. A P value <.05 was considered significant. RESULTS: In total, 7,549 IPC and 2,037 NSQIP patients were compared. The complex SSI rate for NSQIP was higher compared to IPC (THR: 1.19 vs 0.68 [P = .147]; TKR: 0.92 vs 0.80 [P = .682]). After matching, 7 SSIs were identified by both IPC and NSQIP; 3 were identified only by IPC, and 12 were identified only by NSQIP (positive agreement, 0.48; negative agreement, 1.0; κ = 0.48). CONCLUSIONS: Different approaches to monitor SSIs may lead to different results and trending patterns. NSQIP reports total SSI rates that are consistently higher than IPC. If systems are compared at any point in time, confidence on the data may be eroded. Stakeholders need to be aware of these variations and education provided to facilitate an understanding of differences and a consistent approach to SSI surveillance monitoring over time.

Health-related quality of life with long-term retention of the PROSthesis of Antibiotic Loaded Acrylic Cement system following infection resolution in low demand patients.

BACKGROUND: The study purpose was to (1) evaluate health-related quality of life (HRQL) with the PROSthesis of Antibiotic Loaded Acrylic Cement (PROSTALAC) in situ for infected total hip arthroplasty (THA), (2) determine infection resolution, and (3) compare subjects who underwent second stage surgery with those who retained the PROSTALAC on a longer term basis. METHODS: Demographics, physical demand level, and comorbidities were recorded prospectively in 29 subjects followed to at least 24 months after initial PROSTALAC insertion. HRQL was evaluated using the Western Ontario McMaster Osteoarthritis Index (WOMAC) and RAND 36-Item Health Survey. Infection resolution was determined using a pre-specified clinical definition. RESULTS: Twenty-five of 29 (86%) subjects' infections resolved. Three subjects died, of whom two had resolved infections. For survivors, 22/26 (85%) completed HRQL evaluations. After PROSTALAC insertion, pain and function improved within 3-6 months and was retained at 24 months. Of those followed to 24 months, 7/22 (32%) subjects underwent second stage surgery. They were higher physical demand subjects ( p = 0.03) than those not undergoing second stage surgery. We found no difference in WOMAC scores at 24 months between those who underwent second stage surgery and those who retained the PROSTALAC ( p > 0.32). DISCUSSION: The PROSTALAC system for THA appears to allow acceptable HRQL while in situ for at least 2 years in low physical demand patients. Subjects with higher physical demand levels are more likely to undergo second stage surgery. CONCLUSION: Further evaluation is required to determine whether longer term PROSTALAC retention may be appropriate for specific patient groups.

Acute nosocomial HCV infection detected by NAT of a regular blood donor.

BACKGROUND: Routine HCV NAT of blood donors to detect persons in the preseroconversion phase of acute infection was introduced in Canada in October 1999. The source of virus exposure was investigated in the first, and to date only, blood donor found to be HCV NAT positive, anti-HCV negative in Canada. He was a regular donor with none of the commonly reported risk factors for HCV infection. STUDY DESIGN AND METHODS: Epidemiologic follow-up revealed that the blood donor had received antibiotics at an outpatient IV clinic 5 weeks before donation. IV solution bags and tubing for individual patients were stored in the clinic, and then the same equipment was used each time the patient returned for the next dose of antibiotics until it was replaced after every 72-hour period. Among eight other patients whose clinic visitation times overlapped was a man with chronic HCV infection. Genomic sequencing of HCV isolates from the blood donor, the patient with chronic hepatitis C, and local controls was carried out to study possible nosocomial infection. RESULTS: Genomic sequencing showed a high degree of relatedness in the hypervariable region of HCV isolates from the blood donor and putative source patient as compared with controls. Detailed molecular analysis of quasispecies of the HCV isolates further indicated that viruses from the two individuals were genetically very close to each other. CONCLUSION: The introduction of routine screening of blood donors by HCV NAT was directly responsible for the early detection and investigation of an unusual case of HCV infection involving a regular donor. Genomic sequencing studies provided firm evidence of patient-to-patient transmission of HCV in an IV clinic. The report clearly demonstrates the value of molecular fingerprinting in tracking nosocomial HCV infections.