Arrival of the rare carbapenemase OXA-204 in Canada causing a multispecies outbreak over 3 years.

OBJECTIVES: To investigate a persistent multispecies OXA-204 outbreak occurring simultaneously in multiple distant hospitals in the province of Quebec, Canada. METHODS: OXA-204 carbapenemase-producing Enterobacterales (CPE) isolated from multiple hospitals between January 2016 and October 2018 were included in the study. An epidemiological inquiry was conducted in order to elucidate possible transmission routes and a putative source. Isolates were characterized by standardized antibiotic susceptibility testing and by WGS, using Illumina short-read data and MinION long-read data. RESULTS: The outbreak comprised 65 patients and 82 isolates from four hospital sites. Most patients were ≥65 years old, had multiple comorbidities and had received antibiotics recently. The infection to colonization ratio was 1:20. No persistent environmental reservoir was identified. The most frequent organism was Citrobacter freundii (n = 78), followed by Klebsiella spp. (n = 3) and Escherichia coli (n = 1). WGS analysis showed 77/78 C. freundii isolates differing by 0-26 single nucleotide variants (SNVs). Results of WGS analysis showed blaOXA-204 was present on three plasmids types (IncX1, IncA/C2 and IncFII/FIB/A/C2) and on a prophage. All C. freundii isolates harboured multiple copies of blaOXA-204, both on the chromosome and a plasmid. Plasmid IncFII/FIB/A/C2 was observed in all three species. CONCLUSIONS: Transfer of OXA-204 plasmids likely occurred between species within the same patient, highlighting the plasticity of these plasmids and potential for widespread dissemination. OXA-204 carbapenemase has been introduced into Quebec and has rapidly disseminated. Although the infection to colonization ratio was low in this outbreak, this carbapenemase has been associated with severe infection elsewhere.

Carbapenemase-producing Enterobacteriaceae in the UK: a national study (EuSCAPE-UK) on prevalence, incidence, laboratory detection methods and infection control measures.

OBJECTIVES: To estimate UK prevalence and incidence of clinically significant carbapenemase-producing Enterobacteriaceae (CPE), and to determine epidemiological characteristics, laboratory methods and infection prevention and control (IPC) measures in acute care facilities. METHODS: A 6 month survey was undertaken in November 2013-April 2014 in 21 sentinel UK laboratories as part of the European Survey on Carbapenemase-Producing Enterobacteriaceae (EuSCAPE) project. Up to 10 consecutive, non-duplicate, clinically significant and carbapenem-non-susceptible isolates of Escherichia coli or Klebsiella pneumoniae were submitted to a reference laboratory. Participants answered a questionnaire on relevant laboratory methods and IPC measures. RESULTS: Of 102 isolates submitted, 89 (87%) were non-susceptible to ≥1 carbapenem, and 32 (36%) were confirmed as CPE. CPE were resistant to most antibiotics, except colistin (94% susceptible), gentamicin (63%), tigecycline (56%) and amikacin (53%). The prevalence of CPE was 0.02% (95% CI = 0.01%-0.03%). The incidence of CPE was 0.007 per 1000 patient-days (95% CI = 0.005-0.010), with north-west England the most affected region at 0.033 per 1000 patient-days (95% CI = 0.012-0.072). Recommended IPC measures were not universally followed, notably screening high-risk patients on admission (applied by 86%), using a CPE 'flag' on patients' records (70%) and alerting neighbouring hospitals when transferring affected patients (only 30%). Most sites (86%) had a laboratory protocol for CPE screening, most frequently using chromogenic agar (52%) or MacConkey/CLED agars with carbapenem discs (38%). CONCLUSIONS: The UK prevalence and incidence of clinically significant CPE is currently low, but these MDR bacteria affect most UK regions. Improved IPC measures, vigilance and monitoring are required.

Survey of infection control practices in hemodialysis units: preventing vascular access-associated bloodstream infections.

OBJECTIVE: Despite surveillance, the Quebec Healthcare-Associated Infections Surveillance Program saw no improvement in vascular access-associated bloodstream infections in hemodialysis (HD). We aimed to determine the infection control measures recommended and implemented in Quebec's HD units, compliance of local protocols to infection control practice guidelines, and reasons behind the low prevalence of arteriovenous fistulas. METHODS: An online survey was elaborated on the basis of the Centers for Disease Control and Prevention (CDC) and National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines. The questionnaire was validated (construct, content, face validity, and reliability) and sent to all HD units in Quebec (n = 40). Results were analyzed using descriptive statistics, linear regression, and Poisson regression. RESULTS: Thirty-seven (93%) of 40 HD units participated. Thirty (94%) of the 32 centers where central catheters are inserted have written insertion protocols. Compliance with practice guidelines is good, except for full-body draping during catheter insertion (79%) and ointment use at insertion site (3%). Prevention measures for catheter maintenance are in accordance with guidelines, except for skin disinfection with at least 0.5% chlorhexidine and 70% alcohol (67% compliance) and regular antiseptic ointment use at the insertion site (3%). Before fistula cannulation, skin preparation is suboptimal; forearm hygiene is performed in only 61% of cases. Several factors explain the low rate of fistulas, including patient preference (69%) and lack of surgical resources (39%; P = .01). CONCLUSIONS: Improvement in standardization of care according to practice guidelines is necessary. Fistula rate could be increased by improving access to surgical resources and patient education. Strategies are now being elaborated to address these findings.

Methicillin-resistant Staphylococcus aureus colonization among medical residents.

BACKGROUND: Medical residents may be at risk of becoming colonized by methicillin-resistant Staphylococcus aureus (MRSA) during their training. The occupational risk of this specific population is unknown. Furthermore, there are no data regarding MRSA colonization among health care professionals in Quebec. OBJECTIVE: To determine the MRSA colonization rate in Laval University (Quebec City, Quebec) medical residents and compare it with the MRSA colonization rate of a control group. METHODS: A controlled cross-sectional study of MRSA prevalence among medical residents of Laval University was performed. The control group consisted of Laval University undergraduate medical students without previous clinical rotations in their curriculum. After informed consent was obtained, participants were screened for MRSA with a nasal swab in both anterior nares. They also completed a questionnaire regarding relevant risk factors and demographic data. RESULTS: A total of 250 residents of all residency levels from medical and surgical specialties and 247 controls were recruited between February and April 2010. One case of MRSA colonization was detected among the residents and none in the control group (prevalence of 0.4% versus 0.0%; P=1.00). DISCUSSION: MRSA nasal carriage was very low among Laval University residents. This may reflect the decreasing rate of health care-associated MRSA in Quebec City. Young age and good health may also explain this low risk. The strict infection control policies for MRSA patients (including cohorting, use of gloves, gown and patient-dedicated equipment) may also contribute to prevent MRSA transmission. CONCLUSIONS: Medical residents in Quebec City appeared to be at very low risk of contracting MRSA through professional activities.

HISTORIQUE: Les résidents en médecine peuvent être à risque d'être colonisés par le Staphylococcus aureus résistant à la méthicilline (SARM) pendant leur formation. On ne connaît pas le risque professionnel de cette population. De plus, il n'existe pas de données sur la colonisation par le SARM des professionnels de la santé au Québec. OBJECTIF: Déterminer le taux de colonisation par le SARM des résidents en médecine de l'Université Laval (de Québec, au Québec) et le comparer à celui d'un groupe témoin. MÉTHODOLOGIE: Les chercheurs ont mené une étude transversale contrôlée de la prévalence du SARM chez les résidents en médecine de l'Université Laval. Le groupe témoin se composait d'étudiants en médecine non spécialisés de l'Université Laval qui n'avaient pas encore fait de rotations cliniques dans leur cursus. Après avoir donné leur consentement éclairé, les participants ont subi un test de dépistage du SARM au moyen d'un prélèvement dans les deux narines. Ils ont également rempli un questionnaire au sujet des facteurs de risque pertinents et des données démographiques. RÉSULTATS: Au total, les chercheurs ont recruté 250 résidents de toutes les années de résidence en spécialité de la médecine et de la chirurgie et 247 sujets témoins entre février et avril 2010. Ils ont dépisté un cas de colonisation par le SARM chez les résidents et n'en ont trouvé aucun dans le groupe témoin (prévalence de 0,4 % par rapport à 0,0 %; P=1,00). EXPOSÉ: Le portage nasal du SARM était très faible chez les résidents de l'Université Laval. Ce constat peut refléter le taux décroissant de SARM associés aux soins de santé dans la ville de Québec. Un jeune âge et une bonne santé peuvent également expliquer ce faible risque. Les politiques de contrôle des infections rigoureuses liées aux patients ayant un SARM (y compris le regroupement en cohortes, le port des gants et l'utilisation d'une blouse et de matériel réservés au patient) peuvent également contribuer à prévenir la transmission du SARM. CONCLUSIONS: Les résidents en médecine de la ville de Québec semblaient très peu à risque de contracter un SARM à cause de leurs activités professionnelles.