Risk Factors for Cryptococcus gattii Infection, British Columbia, Canada

To determine whether particular environmental, medical, or behavioral risk factors existed among Cryptcoccus gattii–infected persons compared with the general population, we conducted a sex-matched case−control study on a subset of case-patients in British Columbia (1999–2001). Exposures and underlying medical conditions among all case-patients (1999–2007) were also compared with results of provincial population–based surveys and studies. In case−control analyses, oral steroids (matched odds ratio [MOR] 8.11, 95% confidence interval [CI] 1.74–37.80), pneumonia (MOR 2.71, 95% CI 1.05–6.98), and other lung conditions (MOR 3.21, 95% CI 1.08–9.52) were associated with infection. In population comparisons, case-patients were more likely to be >50 years of age (p<0.001), current smokers (p<0.001), infected with HIV (p<0.001), or have a history of invasive cancer (p<0.001). Although C. gattii is commonly believed to infect persons with apparently healthy immune systems, several immunosuppressive and pulmonary conditions seem to be risk factors

Research Article Genomic Analysis of a Serotype 5 Streptococcus pneumoniae Outbreak in British Columbia

Background. Streptococcus pneumoniae can cause a wide spectrum of disease, including invasive pneumococcal disease (IPD). From 2005 to 2009 an outbreak of IPD occurred in Western Canada, caused by a S. pneumoniae strain with multilocus sequence type (MLST) 289 and serotype 5. We sought to investigate the incidence of IPD due to this S. pneumoniae strain and to characterize the outbreak in British Columbia using whole-genome sequencing. Methods. IPD was defined according to Public Health Agency of Canada guidelines. Two isolates representing the beginning and end of the outbreak were whole-genome sequenced. The sequences were analyzed for single nucleotide variants (SNVs) and putative genomic islands. Results. The peak of the outbreak in British Columbia was in 2006, when 57% of invasive S. pneumoniae isolates were serotype 5. Comparison of two whole-genome sequenced strains showed only 10 SNVs between them. A 15.5 kb genomic island was identified in outbreak strains, allowing the design of a PCR assay to track the spread of the outbreak strain. Discussion. We show that the serotype 5 MLST 289 strain contains a distinguishing genomic island, which remained genetically consistent over time. Whole-genome sequencing holds great promise for real-time characterization of outbreaks in the future and may allow responses tailored to characteristics identified in the genome

Erysipelothrix rhusiopathiae endocarditis and presumed osteomyelitis

Erysipelothrix rhusiopathiae is known to cause infections in humans following exposure to decaying organic matter or animals colonized with the organism, such as swine and fish. Invasive infections with this organism are unusual and are manifested primarily as infective endocarditis. The present report is believed to be the first to report a case of E rhusiopathiae endocarditis and presumptive osteomyelitis. E rhusiopathiae appears to have intrinsic resistance to vancomycin. Because vancomycin is often used empirically for the treatment of endocarditis, rapid differentiation of E rhusiopathiae from other Gram-positive organisms is critical. In patients with endocarditis caused by a Gram-positive bacillus and epidemiological risk factors for E rhusiopathiae exposure, empirical treatment with vancomycin should be reconsidered

Human Clinical Isolates of Corynebacterium diphtheriae and Corynebacterium ulcerans Collected in Canada from 1999 to 2003 but Not Fitting Reporting Criteria for Cases of Diphtheria

A 5-year collection of Corynebacterium diphtheriae and Corynebacterium ulcerans human clinical isolates yielded nine isolates from blood cultures of patients with invasive infections, stressing the importance of C. diphtheriae as a serious blood-borne pathogen. Seven percent of C. diphtheriae and 100% of C. ulcerans isolates produced diphtheria toxin, demonstrating that toxigenic corynebacteria continue to circulate

Comparison of outcomes in patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia who are treated with β-lactam vs vancomycin empiric therapy: a retrospective cohort study

Background: Prior studies suggested that vancomycin may be inferior to β-lactams for the empiric treatment of methicillin-susceptible S. aureus (MSSA) bacteremia. We assessed whether empiric therapy with β-lactams compared to vancomycin was associated with differences in clinical outcomes in patients with MSSA bacteremia. Methods We conducted a retrospective cohort study of adult inpatients with their first episode of MSSA bacteremia at two tertiary care hospitals in Vancouver, Canada, between 2007 and 2014. Exposure was either empiric β-lactam or vancomycin therapy. All patients received definitive treatment with cloxacillin or cefazolin. The primary outcome was 28-day mortality. Secondary outcomes were 90-day mortality, recurrent infection at 6 months, duration of bacteremia and hospital length-of-stay. Outcomes were adjusted using multivariable logistic regression. Results Of 814 patients identified, 400 met inclusion criteria (β-lactam = 200, vancomycin = 200). Overall 28-day mortality was 8.5 % (n=34). There were more cases of infective endocarditis in the β-lactam than in the vancomycin group [45 (22.5 %) vs 23 (11.5 %), p < 0.01]. Adjusted mortality at 28 days was similar between the two groups (OR: 1.14; 95 % CI: 0.49–2.64). No differences in secondary outcomes were observed. Transition to cloxacillin or cefazolin occurred within a median of 67.8 h in the vancomycin group. Conclusions Empiric therapy with β-lactams was not associated with differences in all-cause mortality, recurrent infection, microbiological cure or hospital length-of-stay compared to vancomycin. Vancomycin monotherapy may be appropriate for the empiric treatment of MSSA bacteremia if definitive therapy with cloxacillin or cefazolin can be initiated within 3 days.Medicine, Faculty ofPathology and Laboratory Medicine, Department ofReviewedFacult

Editorial Expression of Concern: Comparative effectiveness of β-lactam versus vancomycin empiric therapy in patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia

An amendment to this paper has been published and can be accessed via the original article.Medicine, Faculty ofNon UBCPathology and Laboratory Medicine, Department ofReviewedFacult

Comparative effectiveness of β-lactam versus vancomycin empiric therapy in patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia

Background: Vancomycin may be inferior to β-lactams for the empiric treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. We compared empiric β-lactams to vancomycin to assess clinical outcomes in patients with MSSA bacteremia. Methods: We conducted a retrospective cohort study of adult inpatients with their first episode of MSSA bacteremia at two tertiary care hospitals in Vancouver, Canada, between 2007 and 2014. Exposure was either empiric β-lactam with or without vancomycin or vancomycin monotherapy. All patients received definitive treatment with cloxacillin or cefazolin. The primary outcome was 28-day mortality. Secondary outcomes were 90-day mortality, duration of bacteremia, and hospital length-of-stay. Outcomes were adjusted using multivariable logistic regression. Results: Of 669 patients identified, 255 met inclusion criteria (β-lactam = 131, vancomycin = 124). Overall 28-day mortality was 7.06 % (n = 18). There were more cases of infective endocarditis in the β-lactam than in the vancomycin group [24 (18.3 %) vs 12 (9.7 %), p = 0.05]. Adjusted mortality at 28 days was similar between the two groups (OR 0.85; 95 % CI 0.27–2.67). The duration of bacteremia was longer in the vancomycin group (97.1 vs 70.7 h, p = 0.007). Transition to cloxacillin or cefazolin occurred within a median of 68.3 h in the vancomycin group. Conclusions: Empiric β-lactams was associated with earlier clearance of bacteremia by a median of 1 day compared to vancomycin. Future prospective studies are needed to confirm our findings.Medicine, Faculty ofOther UBCNon UBCPathology and Laboratory Medicine, Department ofReviewedFacult