Emergence of Carbapenemase-Producing Enterobacteriaceae, South-Central Ontario, Canada1.

We analyzed population-based surveillance data from the Toronto Invasive Bacterial Diseases Network to describe carbapenemase-producing Enterobacteriaceae (CPE) infections during 2007-2015 in south-central Ontario, Canada. We reviewed patients' medical records and travel histories, analyzed microbiologic and clinical characteristics of CPE infections, and calculated incidence. Among 291 cases identified, New Delhi metallo-ß-lactamase was the predominant carbapenemase (51%). The proportion of CPE-positive patients with prior admission to a hospital in Canada who had not received healthcare abroad or traveled to high-risk areas was 13% for patients with oxacillinase-48, 24% for patients with New Delhi metallo-ß-lactamase, 55% for patients with Klebsiella pneumoniae carbapenemase, and 67% for patients with Verona integron-encoded metallo-ß-lactamase. Incidence of CPE infection increased, reaching 0.33 cases/100,000 population in 2015. For a substantial proportion of patients, no healthcare abroad or high-risk travel could be established, suggesting CPE acquisition in Canada. Policy and practice changes are needed to mitigate nosocomial CPE transmission in hospitals in Canada.

Patient- and hospital-level predictors of vancomycin-resistant Enterococcus (VRE) bacteremia in Ontario, Canada.

BACKGROUND: Data are limited on risk factors for vancomycin-resistant Enterococcus (VRE) bacteremia. METHODS: All patients with a confirmed VRE bacteremia in Ontario, Canada, between January 2009 and December 2013 were linked to provincial healthcare administrative data sources and frequency matched to 3 controls based on age, sex, and aggregated diagnosis group. Associations between predictors and VRE bacteremia were estimated by generalized estimating equations and summarized using odds ratios (ORs) and corresponding 95% confidence intervals (CIs). RESULTS: In total, 217 cases and 651 controls were examined. In adjusted analyses, patient-level predictors included bone marrow transplant (OR 106.99 [95% CI 12.19-939.26]); solid organ transplant (OR 17.17 [95% CI 4.95-59.54]); any cancer (OR 8.64 [95% CI 3.88-19.21]); intensive care unit (ICU) admission (OR 6.81 [95% CI 3.53-13.13]); heart disease (OR 5.27 [95% CI 2.00-13.90]); and longer length of stay (OR 1.07 per day [95% CI 1.06-1.09]). Hospital-level predictors included hospital size (per increase in 100 beds (OR 1.26 [95% CI 1.07-1.48]) and teaching hospitals (OR 3.87 [95% CI 1.85-8.08]). CONCLUSIONS: Patients with a bone marrow transplant, solid organ transplant, cancer, or who are admitted to the ICU are at highest risk of VRE bacteremia, particularly at large hospitals and teaching hospitals.

Influence of an independent quarterly audit on publicly reported vancomycin-resistant enterocococi bacteremia data in Ontario, Canada.

BACKGROUND: All Ontario hospitals are mandated to self-report vancomycin-resistant enterocococi (VRE) bacteremias to Ontario's Ministry of Health and Long-term Care for public reporting purposes. Independent quarterly audits of publicly reported VRE bacteremias between September 2013 and June 2015 were carried out by Public Health Ontario. VRE bacteremia case-reporting errors between January 2009 and August 2013 were identified by a single retrospective audit. METHODS: Employing a quasiexperimental pre-post study design, the relative risk of VRE bacteremia reporting errors before and after quarterly audits were modeled using Poisson regression adjusting for hospital type, case counts reported to the Ministry of Health and Long-term Care, and autocorrelation via generalized estimating equation. RESULTS: Overall, 24.5% (126 out of 514) of VRE bacteremias were reported in error; 114 out of 367 (31%) VRE bacteremias reported before quarterly audits and 12 out of 147 (8.1%) reported after audits were found to be incorrect. In adjusted analysis, quarterly audits of VRE bacteremias were associated with significant reductions in reporting errors when compared with before quarterly auditing (relative risk, 0.17; 95% confidence interval, 0.05-0.63). Risk of reporting errors among community hospitals were greater than acute teaching hospitals of the region (relative risk, 4.39; 95% CI, 3.07-5.70). CONCLUSIONS: This study found independent quarterly audits of publicly reported VRE bacteremias to be associated with significant reductions in reporting errors. Public reporting systems should consider adopting routine data audits and hospital-targeted training to improve data accuracy.

VRE and VSE Bacteremia Outcomes in the Era of Effective VRE Therapy: A Systematic Review and Meta-analysis.

BACKGROUND Prior data suggest that vancomycin-resistant Enterococcus (VRE) bacteremia is associated with worse outcomes than vancomycin-sensitive Enterococcus (VSE) bacteremia. However, many studies evaluating such outcomes were conducted prior to the availability of effective VRE therapies. OBJECTIVE To systematically review VRE and VSE bacteremia outcomes among hospital patients in the era of effective VRE therapy. METHODS Electronic databases and grey literature published between January 1997 and December 2014 were searched to identify all primary research studies comparing outcomes of VRE and VSE bacteremias among hospital patients, following the availability of effective VRE therapies. The primary outcome was all-cause, in-hospital mortality, while total hospital length of stay (LOS) was a secondary outcome. All meta-analyses were conducted in Review Manager 5.3 using random-effects, inverse variance modeling. RESULTS Among all the studies reviewed, 12 cohort studies and 1 case control study met inclusion criteria. Similar study designs were combined in meta-analyses for mortality and LOS. VRE bacteremia was associated with increased mortality compared with VSE bacteremia among cohort studies (odds ratio [OR], 1.80; 95% confidence interval [CI], 1.38-2.35; I2=0%; n=11); the case-control study estimate was similar, but not significant (OR, 1.93; 95% CI, 0.97-3.82). LOS was greater for VRE bacteremia patients than for VSE bacteremia patients (mean difference, 5.01 days; 95% CI, 0.58-9.44]; I2=0%; n=5). CONCLUSIONS Despite the availability of effective VRE therapy, VRE bacteremia remains associated with an increased risk of in-hospital mortality and LOS when compared to VSE bacteremia. Infect. Control Hosp. Epidemiol. 2015;37(1):26-35.

Community-associated methicillin-resistant Staphylococcus aureus in northwest Ontario: A five-year report of incidence and antibiotic resistance.

BACKGROUND: The incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is traditionally high in remote areas of Canada with large Aboriginal populations. Northwestern Ontario is home to 28,000 First Nations people in more than 30 remote communities; rates of CA-MRSA are unknown. OBJECTIVE: To determine the CA-MRSA rates and antibiotic susceptibilities in this region. METHODS: A five-year review of laboratory and patient CA-MRSA data and antibiotic susceptibility was undertaken. RESULTS: In 2012, 56% of S aureus isolates were CA-MRSA strains, an increase from 31% in 2008 (P=0.06). Reinfection rates have been increasing faster than new cases and, currrently, 25% of infections are reinfections. CA-MRSA isolates continue to be susceptible to many common antibiotics (nearly 100%), particularly trimethoprim/sulfamethoxazole, clindamycin and tetracycline. Erythromycin susceptibility stands at 58%. DISCUSSION: Rates of CA-MRSA, as a percentage of all S aureus isolates, were higher than those reported in other primary care series. The infection rate per 100,000 is one the highest reported in Canada. Antibiotic susceptibilities were unchanged during the study period; the 99% susceptibility rate to clindamycin differs from a 2010 Vancouver (British Columbia) study that reported only a 79% susceptibility to this antibiotic. CONCLUSION: There are very high rates of CA-MRSA infections in northwestern Ontario. Disease surveillance and ongoing attention to antibiotic resistance is important in understanding the changing profile of MRSA infections. Social determinants of health, specifically improved housing and sanitation, remain important regional issues.

HISTORIQUE: L'incidence de Staphylococcus aureus résistant à la méthicilline d'origine non nosocomiale (SARM-ONN) est généralement élevée dans les régions éloignées du Canada aux fortes populations autochtones. Ainsi, 28 000 membres des Premières nations habitent dans plus de 30 communautés éloignées du nord-ouest de l'Ontario. On n'y connaît pas le taux de SARM-ONN. OBJECTIF: Déterminer le taux de SARM-ONN et les susceptibilités aux antibiotiques dans cette région. MÉTHODOLOGIE: Les chercheurs ont effectué une analyse quinquennale des données de laboratoire et des données des patients à l'égard du SARM-ONN ainsi que de leur susceptibilité aux antibiotiques. RÉSULTATS: En 2012, 56 % des isolats de S aureus étaient des souches de SARM-ONN, soit une augmentation par rapport aux 31 % de 2008 (P=0,06). Le taux de réinfection augmentait plus rapidement que le taux de nouveaux cas : 25 % des infections sont désormais des réinfections. Les isolats de SARM-ONN continuent d'être susceptibles à de nombreux antibiotiques courants (près de 100 %), notamment le triméthoprim-sulfaméthoxazole, la clindamycine et la tétracycline. La susceptibilité à l'érythromycine est de 58 %. EXPOSÉ: Le taux de SAMR-ONN, à titre de pourcentage de tous les isolats de S aureus, était plus élevé que celui déclaré dans d'autres séries de soins de première ligne. Le taux d'infection sur 100 000 habitants est l'un des plus élevés à être signalé au Canada. Les susceptibilités aux antibiotiques demeuraient inchangées pendant la période de l'étude. Le taux de susceptibilité de 99 % à la clindamycine diffère de celui de seulement 79 % obtenu dans une étude de 2010 menée à Vancouver, en Colombie-Britannique. CONCLUSION: Les chercheurs ont constaté un taux très élevé d'infections par le SARM-ONN au nord-ouest de l'Ontario. Il est important de surveiller la maladie et de demeurer attentif à l'antibiorésistance pour comprendre l'évolution du profil des infections par le SARM. Les déterminants sociaux de la santé, particulièrement l'amélioration des logements et des mesures d'assainissement, continuent de représenter d'importants problèmes régionaux.

Assessing secondary attack rates among household contacts at the beginning of the influenza A (H1N1) pandemic in Ontario, Canada, April-June 2009: a prospective, observational study.

BACKGROUND: Understanding transmission dynamics of the pandemic influenza A (H1N1) virus in various exposure settings and determining whether transmissibility differed from seasonal influenza viruses was a priority for decision making on mitigation strategies at the beginning of the pandemic. The objective of this study was to estimate household secondary attack rates for pandemic influenza in a susceptible population where control measures had yet to be implemented. METHODS: All Ontario local health units were invited to participate; seven health units volunteered. For all laboratory-confirmed cases reported between April 24 and June 18, 2009, participating health units performed contact tracing to detect secondary cases among household contacts. In total, 87 cases and 266 household contacts were included in this study. Secondary cases were defined as any household member with new onset of acute respiratory illness (fever or two or more respiratory symptoms) or influenza-like illness (fever plus one additional respiratory symptom). Attack rates were estimated using both case definitions. RESULTS: Secondary attack rates were estimated at 10.3% (95% CI 6.8-14.7) for secondary cases with influenza-like illness and 20.2% (95% CI 15.4-25.6) for secondary cases with acute respiratory illness. For both case definitions, attack rates were significantly higher in children under 16 years than adults (25.4% and 42.4% compared to 7.6% and 17.2%). The median time between symptom onset in the primary case and the secondary case was estimated at 3.0 days. CONCLUSIONS: Secondary attack rates for pandemic influenza A (H1N1) were comparable to seasonal influenza estimates suggesting similarities in transmission. High secondary attack rates in children provide additional support for increased susceptibility to infection.

The expression of two novel orange-spotted grouper (Epinephelus coioides) TNF genes in peripheral blood leukocytes, various organs, and fish larvae.

The tumour necrosis factor (TNF) super-family is a group of important cytokines involved in inflammation, apoptosis, cell proliferation, and the general stimulation of the immune system. The TNF gene has been cloned in some bony fish; however, its counterparts are still unidentified in the majority of fish species. In this study, we cloned gTNF-1 and gTNF-2 from the orange-spotted grouper (Epinephelus coioides), an economically important farmed fish. Both genes include 4 exons and 3 introns and encoded 253 and 241 amino acid proteins with a molecular weight of approximately 27 and 26 kDa, respectively. The identity of the putative amino acid sequences between gTNF-1 and gTNF-2 was only 38%. The positions of cysteine residues, a protease cleavage site, and a transmembrane domain sequence derived from gTNF-1 and gTNF-2 were similar to those in other fish and mammalian TNF-α. The mRNA expression levels of the 2 gTNF molecules were evaluated in unstimulated/stimulated peripheral blood leukocytes, various organs, and fish larvae. Following lipopolysaccharide (LPS) treatment, gTNF-2 was expressed at higher levels, was up-regulated more quickly, and was more sensitive to the immune response than gTNF-1. gTNF-1 was constitutively expressed in the thymus, brain, and spleen, but it was also expressed in the heart, head kidney, and trunk kidney after LPS stimulation. gTNF-2 was constitutively expressed in the thymus, head kidney, trunk kidney, spleen, and intestine; further, gTNF-2 was highly expressed in all organs post-LPS stimulation. Finally, the gTNF expression levels were evaluated at various developmental stages in grouper larvae. A higher variation of gTNF expression levels was observed in fish larvae from a contaminated hatchery. This study revealed the different expression patterns of gTNF-1 and gTNF-2. In addition, gTNF-2 was more sensitive to pathogens than gTNF-1; therefore, it may be an appropriate marker for pathogen invasion and the evaluation of the larval rearing environment.

Does the presence of a tracheal bronchus affect the margin of safety of double-lumen tube placement?

During double-lumen tube (DLT) placement, the anesthesiologist must be mindful of the margin of safety. We determined how this margin is affected by the presence of a tracheal bronchus by elucidating the mathematical relationship between some relevant physical dimensions of the trachea, bronchi, and DLT. Our results suggest that a tracheal bronchus only rarely affects the intrinsic margin of safety of DLT placement. When the tracheal bronchus is located much higher than its most frequently seen location (within 2 cm from the carina), however, there is increased risk that it could be blocked by the tracheal cuff of a left-sided DLT.