Use of whole genomic sequencing to detect New Delhi metallo-B-lactamase (NDM)-producing Escherichia coli outbreak associated with endoscopic procedures.

BACKGROUND: Whole-genome sequencing (WGS) has emerged as an alternative genotyping tool for outbreak investigations in the healthcare setting. We describe the investigation and control of a New Delhi metallo-B-lactamase (NDM)-producing Escherichia coli cluster in Southeast Michigan. METHODS: Michigan Bureau of Laboratories identified several closely related NDM-producing E. coli isolates with WGS. An epidemiologic investigation, including case-control study, assessment of infection control practices, and endoscope culturing, was performed to identify source of transmission. Targeted screening of potentially exposed patients was performed following identification of probable source. RESULTS: Between July 2021 and February 2023, nine patients were identified. Phylogenetic analysis confirmed the isolates were closely related with less than 26 single nucleotide polymorphism (SNP) differences between isolates, suggesting an epidemiological link. Eight (89%) patients had a duodenoscope and/or gastroscope exposure. Cases were compared with 23 controls. Cases had significantly higher odds of exposure to duodenoscopes (odds ratio 15.0; 95% CI, 1.8-142.2; P = .015). The mean incubation period, estimated as date of procedure to positive index culture, was 86 days (range, 1-320 days). No lapses in endoscope reprocessing were identified; NDM-producing E. coli was not recovered from reprocessed endoscopes or during targeted screening. No additional cases were identified after removal of implicated gastroscopes and replacement of duodenoscope with disposable end caps. CONCLUSIONS: In this investigation, WGS was utilized to identify transmission of an NDM-producing E. coli outbreak associated with endoscope exposure. Coupled with epidemiologic data, WGS can facilitate outbreak investigations by rapidly identifying linked cases and potential sources to prevent further transmission.

Using interprofessional collaboration to reduce reported rates of central-line-associated bloodstream infection in an intensive care setting.

Using a multicomponent approach that included blood-culture stewardship, evaluation for secondary sources of bloodstream infection, improved documentation, and prompt central-line removal, an interprofessional team improved patient care and reduced central-line-associated bloodstream infection rates in collaboration with the primary team on the surgical intensive care unit.

Tales from the auditors: What we learned from endoscope auditing.

Endoscope auditing is unique from other types of auditing normally completed as part of ongoing quality initiatives. When auditors walk into an endoscopy processing area, they are confronted with a variety of complex processes generally packed into a small space. Auditors are challenged to become experts on the processes they are evaluating, and must stay current with changes in practice and equipment. In our 10 years of endoscope processing assessments completed by infection prevention and accreditation staff, we learned a great deal regarding how to approach auditing and interact with staff to improve the quality of endoscope processing.

Evaluation of contact precautions for methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus.

BACKGROUND: There are limited controlled data demonstrating contact precautions (CPs) prevent methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) infections in endemic settings. We evaluated changes in hospital-acquired MRSA and VRE infections after discontinuing CPs for these organisms. METHODS: This is a retrospective study done at an 800-bed teaching hospital in urban Detroit. CPs for MRSA and VRE were discontinued hospital-wide in 2013. Data on MRSA and VRE catheter-associated urinary tract infections (CAUTIs), ventilator-associated pneumonia (VAP), central line-associated bloodstream infections (CLABSIs), surgical site infections (SSIs), and hospital-acquired MRSA bacteremia (HA-MRSAB) rates were compared before and after CPs discontinuation. RESULTS: There were 36,907 and 40,439 patients hospitalized during the two 12-month periods: CPs and no CPs. Infection rates in the CPs and no-CPs periods were as follows: (1) MRSA infections: VAP, 0.13 versus 0.11 (P = .84); CLABSI, 0.11 versus 0.19 (P = .45); SSI, 0 versus 0.14 (P = .50); and CAUTI, 0.025 versus 0.033 (P = .84); (2) VRE infections: CAUTI, 0.27 versus 0.13 (P = .19) and CLABSI, 0.29 versus 0.3 (P = .94); and (3) HA-MRSAB rates: 0.14 versus 0.11 (P = .55), respectively. CONCLUSIONS: Discontinuation of CPs did not adversely impact endemic MRSA and VRE infection rates.

Nosocomial Outbreak of a Novel Extended-Spectrum ß-Lactamase Salmonella enterica Serotype Isangi Among Surgical Patients.

OBJECTIVE Nosocomial outbreaks caused by Salmonella are rare. We describe the investigation and control of a cluster of novel extended-spectrum ß-lactamase (ESBL) Salmonella enterica serotype Isangi in a hospital in southeastern Michigan. METHODS An epidemiologic investigation, including case-control study, assessment of infection control practices and environmental cultures, was performed to identify modes of transmission. Healthcare workers (HCWs) exposed to case patients were screened. Strain relatedness was determined using pulsed-field gel electrophoresis (PFGE); ESBL confirmation was conducted using real-time PCR. Control measures were implemented to prevent further transmission. RESULTS Between September 2 and October 22, 2015, 19 surgical patients, including 10 organ transplant recipients and 1 HCW, had positive S. Isangi cultures. Of these case patients and HCW, 13 had gastroenteritis, 2 had bacteremia, 1 had surgical-site infection, and 4 were asymptomatic. Pulsed-field gel electrophoresis (PFGE) showed 89.5% similarity among the isolates in these cases. Isolates with resistant-phenotypes possessed plasmid-mediated CTX-M15 ESBL. A total of 19 case patients were compared with 57 control participants. Case patients had significantly higher odds of exposure to an intraoperative transesophageal (TEE) probe (adjusted odds ratio 9.0; 95% confidence interval, 1.12-72.60; P=.02). Possible cross-transmission occurred in the HCW and 2 patients. Cultures of TEE probes and the environment were negative. The outbreak ended after removal of TEE probes, modification of reprocessing procedures, implementation of strict infection control practices, and enhanced environmental cleaning. CONCLUSIONS We report the first nosocomial ESBL S. Isangi outbreak in the United States. Multiple control measures were necessary to interrupt transmission of this gastrointestinal pathogen. Exposure to possibly contaminated TEE probes was associated with transmission. Periodic monitoring of reprocessing procedures of TEE probes may be required to ensure optimal disinfection. Infect Control Hosp Epidemiol 2016;37:954-961.