Outbreak of Vancomycin-resistant Enterococcus faecium in Interventional Radiology: Detection Through Whole-genome Sequencing-based Surveillance

Abstract

Background Vancomycin-resistant enterococci (VRE) are a major cause of hospital-acquired infections. The risk of infection from interventional radiology (IR) procedures is not well documented. Whole-genome sequencing (WGS) surveillance of clinical bacterial isolates among hospitalized patients can identify previously unrecognized outbreaks. Methods We analyzed WGS surveillance data from November 2016 to November 2017 for evidence of VRE transmission. A previously unrecognized cluster of 10 genetically related VRE (Enterococcus faecium) infections was discovered. Electronic health record review identified IR procedures as a potential source. An outbreak investigation was conducted. Results Of the 10 outbreak patients, 9 had undergone an IR procedure with intravenous (IV) contrast ≤22 days before infection. In a matched case-control study, preceding IR procedure and IR procedure with contrast were associated with VRE infection (matched odds ratio [MOR], 16.72; 95% confidence interval [CI], 2.01 to 138.73; P = .009 and MOR, 39.35; 95% CI, 7.85 to infinity; P < .001, respectively). Investigation of IR practices and review of the manufacturer’s training video revealed sterility breaches in contrast preparation. Our investigation also supported possible transmission from an IR technician. Infection prevention interventions were implemented, and no further IR-associated VRE transmissions have been observed. Conclusions A prolonged outbreak of VRE infections related to IR procedures with IV contrast resulted from nonsterile preparation of injectable contrast. The fact that our VRE outbreak was discovered through WGS surveillance and the manufacturer’s training video that demonstrated nonsterile technique raise the possibility that infections following invasive IR procedures may be more common than previously recognized.

Clinical and Genomic Epidemiology of Carbapenem-Nonsusceptible Citrobacter spp. at a Tertiary Health Care Center over 2 Decades

“…We sequenced the genomes of all 20 CNSC isolates on the Illumina platform (Table S1) and constructed a phylogenetic tree that also included an additional 82 carbapenem-susceptible Citrobacter isolates collected by the Enhanced Detection System for Hospital-Associated Transmission (EDS-HAT) project ( Fig. 2 ; Table S4) ( 38 , 39 ). Among the 20 CNSC isolates, C. freundii was the predominant species (60% [12/20]), followed by Citrobacter werkmanii (20% [4/20]), C. koseri (10% [2/20]), and C. farmeri (5% [1/20]).…”

Evolution of Outbreak-Causing Carbapenem-Resistant Klebsiella pneumoniae ST258 at a Tertiary Care Hospital over 8 Years

“…The recently emerged clade II F subclade has caused multiple outbreaks since 2014, and ongoing surveillance shows that it continues to be observed in hospitalized patients. While subclades A1* and F may represent continued reintroductions from the community to our institution, further investigations to identify previously unrecognized sources and transmission routes are required and are a major focus of our ongoing EDS-HAT study (33–35).…”

“…By combining retrospective and systematic prospective isolate collections, this study provided new insights into the dynamic changes occurring among ST258 populations in a single hospital over time. We are now validating the combination of machine learning of electronic health records and WGS surveillance in our EDS-HAT project in an attempt to identify and interrupt transmission of CRKP ST258 and other pathogens associated with serious disease in our hospital (33–35). Tracking of multidrug-resistant and emergent hypervirulent bacterial lineages through WGS surveillance is critical to infection prevention.…”

Clinical and genomic epidemiology of carbapenem-non-susceptibleCitrobacterspp. at a tertiary healthcare center over two decades

“…Table 1), and constructed a phylogenetic tree that also included an additional 82 carbapenem-susceptible Citrobacter spp. isolates collected by the Enhanced Detection System for Hospital-Associated Transmission (EDS-HAT) project (Figure 2) (37, 38) (Supp. Table 4).…”