Multidrug-Resistant Shigella sonnei Bacteremia among Persons Experiencing Homelessness, Vancouver, British Columbia, Canada.

Increased invasive bloodstream infections caused by multidrug resistant Shigella sonnei were noted in Vancouver, British Columbia, Canada, during 2021-2023. Whole-genome sequencing revealed clonal transmission of genotype 3.6.1.1.2 (CipR.MSM5) among persons experiencing homelessness. Improvements in identifying Shigella species, expanding treatment options for multidrug resistant infections, and developing public health partnerships are needed.

Targeted management of influenza A/B outbreaks incorporating the cobas® Influenza A/B & RSV into the virology laboratory.

During the 2017/18 influenza season, the authors' virology laboratory implemented the cobas® Influenza A/B & RSV (Roche Molecular Diagnostics, Pleasanton, CA, USA) for influenza outbreak management in two scenarios: initial outbreak investigation or at outbreak conclusion to avoid prolonged measures. Twenty-seven investigations were conducted, including declaration of 11 influenza A/B outbreaks. Thirty percent of investigations would have missed the standard batched daily laboratory-developed respiratory polymerase chain reaction (PCR), and delayed outbreak confirmation until the following day. The average reduction in turnaround time for influenza A/B testing was 10.2 h. A rapid molecular PCR in specific outbreak scenarios improved timely management of influenza outbreaks.

Performance of the BacT/Alert Virtuo Microbial Detection System for the culture of sterile body fluids: prospective multicentre study.

OBJECTIVES: Continuous monitoring blood culture systems are commonly used for sterile body fluid cultures. In this multicentre study, we evaluated the performance of the new-generation BacT/Alert Virtuo system compared to the BacT/Alert 3D and conventional culture for the recovery of microorganisms from sterile body fluids. METHODS: Peritoneal, cerebrospinal, pericardial, pleural and synovial fluids from adult patients submitted for culture were collected from three different centres. Specimens were inoculated into two bottles of the same bottle type (SA, SN, FA Plus or FN Plus) in equal volumes for simultaneous incubation in the Virtuo and 3D instruments. Each specimen was also Gram stained and seeded to solid media. RESULTS: A total of 811 specimens were inoculated to 1257 bottle pairs. The Virtuo and 3D showed equivalent recovery of clinically significant microorganisms (127/155, 81.9%, vs. 126/155, 81.3%, respectively). Solid media cultures recovered fewer pathogens than either continuous monitoring system (95/155, 61.3%, p <0.001), including significantly fewer Enterobacteriaceae and enterococci. The Virtuo was significantly faster than the 3D in median time to detection of isolates from the same specimen (12.5 (range, 2.8-101.5) hours vs. 15.5 (range, 4.3-78.5) hours, p <0.001). Direct specimen Gram stain detected the eventual pathogen in 30 (26.1%) of 115 significant positive specimens. CONCLUSIONS: The BacT/Alert Virtuo system was equivalent to the 3D system in organism recovery from sterile body fluid culture but showed faster detection of growth as a result of design enhancements.

Shigella flexneri serotype 1 infections in men who have sex with men in Vancouver, Canada.

OBJECTIVES: Outbreaks of shigellosis have been documented in men who have sex with men (MSM), associated with interpersonal transmission and underlying HIV infection. We observed a rise in Shigella flexneri isolates identified in a downtown tertiary-care hospital laboratory located within the city centre community health area (CHA-1) of Vancouver, Canada. The objectives of this study were to evaluate clinical outcomes of shigellosis cases among MSM admitted to hospital and to evaluate trends in Shigella cases within Vancouver, Canada. METHODS: Adult rates of shigellosis were analysed by gender and health region, from 2005 to 2011, followed by retrospective chart review of all hospital laboratory-identified S. flexneri cases from 2008 to 2012. Serotyping and pulsed-field gel electrophoresis (PFGE) were performed on these isolates. RESULTS: Although shigellosis rates in men within CHA-1 did not change from 2005 to 2011 (range 33.4-68.5 per 100 000; P = 0.74), they were significantly higher than in other regions within the city of Vancouver (P ≤ 0.001) and the province of British Columbia (P ≤ 0.001). Shigella flexneri rates in men within CHA-1 increased significantly (range 2.3-51.4 per 100 000; P < 0.001), starting in 2008, and were higher than in other regions within Vancouver (P ≤ 0.01). Seventy-nine isolates of S. flexneri from 72 patients were identified by a single hospital laboratory. All patients were male and predominantly MSM (91.7%) and HIV-infected (86.1%), with most (92.6%) demonstrating CD4 counts ≥ 200 cells/µL. In total, 38.0% required hospitalization. Most (87.3%) had S. flexneri serotype 1 infection, with 72.9% of these representing a single PFGE pattern. CONCLUSIONS: We identified high levels of transmission of a primarily clonal strain of S. flexneri serotype 1 in our local MSM population, resulting in a substantial burden of illness and health care resource use secondary to hospital admissions.

Reduction in community-onset methicillin-resistant Staphylococcus aureus rates in an urban Canadian hospital setting.

Community-onset methicillin resistant Staphylococcus aureus (CO-MRSA) became a prominent cause of infection in North America in 2003, with a peak in the epidemic noted by multiple groups in the USA between 2005 and 2007. We reviewed rates of MRSA in two hospitals in Vancouver, Canada, to observe changes in epidemiology from 2003 to 2011. Episodes of emergency department (ED) MRSA bacteraemia and wounds were extracted from the laboratory database, with rates calculated per 10,000 ED visits. All cases were assumed to be community onset, as they were diagnosed in the ED. A peak in ED MRSA bacteraemias occurred in 2005, at 7·8/10,000 ED visits. By 2011, rates of ED bacteraemia declined significantly to 3·3/10,000 ED visits (P

Economic analysis of vancomycin-resistant enterococci at a Canadian hospital: assessing attributable cost and length of stay.

BACKGROUND: Competing resource demands have resulted in the de-escalation of vancomycin-resistant enterococcus (VRE) control programmes in some Canadian healthcare centres. AIM: To determine the attributable costs and length of stay (LOS) of VRE colonizations/infections in an acute care hospital in Canada. METHODS: Surveillance and financial hospital-based databases were used to conduct analyses with cases and controls from fiscal year 2008-2009 (1 April 2008 to 31 March 2009) at an acute care hospital in downtown Vancouver, Canada. A statistical analysis of attributable costs and LOS was conducted using a generalized linear model. In a secondary analysis, differences in costs and LOS were examined for VRE infections versus colonizations. FINDINGS: A total of 217 patients with VRE and a random sample of 1075 patients without VRE were examined. VRE has a positive and significant impact on patient hospitalization costs and LOS. Overall, the presence of VRE increased the estimated mean cost per patient by 61.9% (95% confidence interval: 42.3-84.3) in relative terms and $17,949 (13,949-21,464) in absolute Canadian dollars. For LOS, the attributable number of days associated with a VRE case mean was 68.0% (41.9-98.9) higher in relative terms and 13.8 days (10.0-16.9) in absolute days. In the secondary analysis comparing VRE infection and colonization costs, no statistically significant difference was found. CONCLUSIONS: Based on this analysis, the attributable cost and LOS of VRE are considerable. These factors should be considered before de-escalation of a hospital VRE control programme.

Polymerase chain reaction assay to detect Clostridium difficile tcdC variants is valuable in characterizing hospital epidemiology.

The epidemiology of nosocomial Clostridium difficile infection (CDI), acquired at two hospitals in Vancouver over a one-year period, was reviewed. Cases were analysed by tcdC polymerase chain reaction, with tcdC variants (18 base pair deletion) highly associated with the NAP1 strain. Of the 214 cases identified, 51.9% were caused by these tcdC variants; these cases occurred more frequently in older patients admitted to the community hospital where the strain was endemic. Overall, at least five out of 24 cases classified as recurrences by surveillance definitions were reinfections. Molecular testing allowed identification of major epidemiological differences between the hospitals studied and provided more accurate classification of CDI cases.

Screening for methicillin-resistant Staphylococcus aureus (MRSA) in community-recruited injection drug users: are throat swabs necessary?

We examined and described colonization of MRSA in the anterior nares and throat from 184 community-recruited injection drug users. Thirty-seven (20%) were positive for MRSA: most (34, 92%) were carriers in the nares; while only three (8%) were carriers detected by throat swabs alone. The majority (29, 78%) of MRSA isolates were PVL positive.

Cutaneous diphtheria in the urban poor population of Vancouver, British Columbia, Canada: a 10-year review.

Between 1998 and 2007, records from 33 patients with cutaneous diphtheria from Vancouver's inner city were reviewed. Cases were associated with injection drug use and poverty. Coinfections with Staphylococcus aureus, Streptococcus pyogenes, and Arcanobacterium haemolyticum occurred. Corynebacterium diphtheriae is endemic in Vancouver's urban core, with strains of multilocus sequence type (MLST) 76 predominating.

Mycobacterium heckeshornense peritonitis in a peritoneal dialysis patient: a case report and review of the literature.

We report the first case of peritonitis attributed to Mycobacterium heckeshornense. This is a rare, non-tuberculous mycobacterium that has been reported as an aetiological agent in a growing number and widening spectrum of infections.

Community-associated methicillin-resistant Staphylococcus aureus is prevalent in wounds of community-based injection drug users.

Injection drug users (IDUs) have an elevated risk for carriage of Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). Cutaneous injection-related infections are common in IDUs but detailed studies are few. Based on a subsample of 218 individuals from a community-recruited cohort of IDUs at a supervised injection facility, we investigated the microbiology and related antibiotic susceptibility profiles of isolates from 59 wounds. Twenty-seven percent of subjects had at least one wound and 25 (43%) were culture positive for S. aureus alone [14 MRSA and 11 (19%) methicillin-susceptible (MSSA) isolates]. Sixteen of 18 MRSA isolates were classified as community associated (CA) by the presence of genes encoding for PVL. MRSA and MSSA occurred in mixed infection with other organisms on three and six occasions, respectively. All CA-MRSA isolates were susceptible to tetracycline, vancomycin and linezolid but only 13% were susceptible to clindamycin compared to 63% of MSSA isolates. The frequency of CA-MRSA is a cause for concern in wound infection in the IDU setting.

Emergence of an invasive clone of nontoxigenic Corynebacterium diphtheriae in the urban poor population of Vancouver, Canada.

Invasive disease due to Corynebacterium diphtheriae is rare in North America. Here we describe the emergence of a predominant clone of a nontoxigenic strain of C. diphtheriae in the impoverished population of Vancouver's downtown core. This clone has caused significant morbidity and contributed to at least two deaths. Over a 5-year period, seven cases of bacteremia due to C. diphtheriae were detected in patients admitted to Vancouver hospitals. Injection drug use, diabetes mellitus, skin colonization/infection with C. diphtheriae, and homelessness all appeared to be related to the development of bacteremia with the organism. Ribotyping of isolates recovered from blood culture revealed a predominant ribotype pattern that has not previously been reported in North America.

Surgical face masks in the operating theatre: re-examining the evidence.

In most modern hospitals, no one is allowed to enter the operating theatre without wearing a surgical face mask. The practice of wearing masks is believed to minimize the transmission of oro- and nasopharyngeal bacteria from operating theatre staff to patients' wounds, thereby decreasing the likelihood of postoperative surgical site infections. In this era of cost-restraints, shrinking hospital budgets, and evidence-based medicine, many health care professionals have begun to re-examine traditional infection control practices. Over the past decade, studies challenging the accepted dogma of surgical face mask usage have been published. Masks that function as protective barriers are another emerging issue. Due to a greater awareness of HIV and other blood-borne viruses, masks are taking on a greater role in protecting health care workers from potentially infectious blood and body fluids. The purpose of this review is to evaluate the latest evidence for and against routine use of surgical face masks in the operating theatre.

Rapid identification of clinical yeast isolates using the colorimetric AUXACOLOR system.

The AUXACOLOR colorimetric system (Sanofi Diagnostics Pasteur, Marnes-la-Coquette, France) for the identification of clinical yeast isolates, was compared in its identification of 100 yeast strains to conventional identification methods. Of the 94 correctly identified isolates, 47% (n = 44) were identified by 24 h, and 100% (n = 94) were identified by 48 h. AUXACOLOR is a simple, rapid and accurate method for the identification of yeast pathogens.