The microbiological outcomes of culture-negative blood specimens using 16S rRNA broad-range PCR sequencing: a retrospective study in a Canadian province from 2018 to 2022.

Broad-range 16S rRNA PCR and sequencing of 1,183 blood specimens from 853 unique patients yielded an interpretable sequence and bacterial identification in 29%, 16S rRNA amplification with uninterpretable sequences in 53%, and no amplification in 18%. This study highlights the potential utility of this technique in identifying fastidious gram-negative and anaerobic bacteria but the frequent recovery of environmental and contaminant organisms argues for its judicious use. IMPORTANCE: The existing literature focuses on its performance compared to blood cultures in patients with sepsis, leaving a gap in the literature regarding other blood specimens in suspected infectious syndrome across the severity spectrum. We aimed to characterize its microbiological outcomes and provide insight into its potential clinical utility.

Microbiological characterization of Pneumocystis jirovecii pneumonia using quantitative PCR from nasopharyngeal specimens: a retrospective study in a Canadian province from 2019 to 2023.

Bronchoalveolar lavage is usually employed for molecular diagnosis of Pneumocystis jirovecii but requires a specialized procedure. By contrast, nasopharyngeal (NP) specimens are easily obtained. In this retrospective study of 35 patients with paired NP and bronchoscopy specimens, NP specimens had a 100% negative percent agreement (95% CI 80.5-100) but only 72.2% positive percent agreement (95% CI 46.5-90.3).

Microbiological Characterization of Actinotignum schaalii Strains Causing Invasive Infections during a Multiyear Period in a Large Canadian Health Care Region.

Actinotignum schaalii is an underrecognized Gram-positive bacillus that is associated with urinary tract infections and cutaneous abscesses. The role of A. schaalii in invasive infections continues to be unappreciated because the bacteria can be isolated from a diverse spectrum of clinical specimens, ranging from being a single pathogen in urine and blood cultures to being deemed a colonizer in polymicrobial anaerobic cultures of sterile fluids and tissues. We conducted a microbiological analysis of clinical isolates obtained from 2012 through 2019. A total of 86 isolates were analyzed; 37 (43%) were from blood cultures, 35 (41%) were from deep wounds and abscesses, 6 (7%) were from urine samples, and the rest were recovered from peritoneal, kidney, and scrotal fluid samples. Urinary tract infections were clinically identified as the source of most cases of bacteremia, although no simultaneous urine cultures yielded positive results. The 16S rRNA gene sequences were available for 32 isolates (37%). Phylogenetic analysis revealed that AS.1/AS.2 strains caused a larger proportion of bloodstream infections (BSIs) (100% versus 52% [P = 0.01]) and trended toward a higher rate of hospitalization (91% versus 76% [P = 0.18]) but had a lower clindamycin MIC90 (0.12 versus >256 µg/mL). Our study emphasizes the emergence of A. schaalii as a pathogen in human urine samples, BSIs, and skin and soft tissue infections. It highlights the pitfalls of current laboratory methods in recovering and identifying this organism from clinical specimens, particularly urine samples. Phylogenetic analysis showed unique genotypic sequences for A. schaalii AS.1/AS.2 strains causing urosepsis, which requires further study to identify potential virulence factors. IMPORTANCE Actinotignum schaalii is an underrecognized Gram-positive bacillus due to its special growth requirements and prior phenotypic identification methods, and it is often mistaken as a contaminant. It has been associated with various clinical syndromes, from urinary tract infections to cutaneous infections. The widespread use of molecular diagnostic methods allowed for improved detection. However, its role in invasive infections remains underappreciated. We conducted a detailed microbiological analysis to improve our understanding of this organism's genotypic and phenotypic characteristics. Our results highlight the pitfalls of clinical laboratory recovery, particularly from urine cultures. Although most BSIs were caused by urinary tract infections, no simultaneous urine cultures identified A. schaalii, largely due to the failure of phenotypic methods to reliably isolate and identify this organism. Additionally, this is the first study demonstrating A. schaalii strains with differences in clinical and microbiological characteristics, raising the possibility of potential bacterial virulence factors contributing to invasive infections.

Characterizing Actinotignum schaalii infections in a large Canadian healthcare region.

Aims: We characterize the epidemiology of Actinotignum schaalii within a large Canadian region after implementation of improved identification methods. Patients & methods: Positive cultures for A. schaalii from a centralized microbiology laboratory in Canada were analyzed. Clinical data were retrieved through administrative databases and chart reviews. Primary outcome was incidence of A. schaalii infections; secondary outcomes included mortality, hospital admission and length of stay. Results & conclusions: 86 unique isolates were studied, 37 bloodstream infections (BSI) and 49 non-BSIs. Patients with BSIs were older with more comorbidities, with urinary tract infections implicated as the most frequent source; skin abscesses caused the most non-BSIs. Hospitalization and 90-day mortality was higher in the BSI group. A. schaalii is an important community-acquired pathogen with the potential to cause invasive infections.

Actinotignum schaalii bacteria require special conditions and substances for their growth. Normally, A. schaalii reside in the urogenital tract without causing harm; however, they can be associated with urinary tract infections. Severe infections are increasingly identified with improved identification methods. This retrospective study included all positive cultures for A. schaalii from a centralized microbiology laboratory in Canada from 2012 to 2019. Eighty-six unique isolates were studied, including 37 bloodstream infections (BSIs) and 49 non-BSIs. The mean incidence rate of infections increased during the study. BSIs were seen in older men with other medical comorbidities and were associated with high hospitalization and mortality. Skin and soft-tissue infections comprised the majority of non-BSIs, occurring in younger patients and who had better clinical outcomes. Our population-based study of A. schaalii infections highlights the potential of this pathogen to cause severe infections.

A case of multisystem inflammatory syndrome in adults following natural infection and subsequent immunization.

Multisystem inflammatory syndrome in adults is a rare and life-threatening complication that follows natural COVID-19 infection and primarily affects young unvaccinated adults. This complication is seldom described following vaccination, which would have important implications for the vaccination timing and platform in this population. COVID-19 vaccines are extremely effective; however, the risk of rare adverse events needs to be balanced with the vaccination benefits.

Comparison of hospitalized patients with COVID-19 who did and did not live in residential care facilities in Montréal: a retrospective case series.

BACKGROUND: As in other jurisdictions, the demographics of people infected with SARS-CoV-2 changed in Quebec over the course of the first COVID-19 pandemic wave, and affected those living in residential care facilities (RCFs) disproportionately. We evaluated the association between clinical characteristics and outcomes of hospitalized patients with COVID-19, comparing those did or did not live in RCFs. METHODS: We conducted a retrospective case series of all consecutive adults (≥ 18 yr) admitted to the Jewish General Hospital in Montréal with laboratory-confirmed SARS-CoV-2 infection from Mar. 4 to June 30, 2020, with in-hospital follow-up until Aug. 6, 2020. We collected patient demographics, comorbidities and outcomes (i.e., admission to the intensive care unit, mechanical ventilation and death) from medical and laboratory records and compared patients who did or did not live in public and private RCFs. We evaluated factors associated with the risk of in-hospital death with a Cox proportional hazard model. RESULTS: In total, 656 patients were hospitalized between March and June 2020, including 303 patients who lived in RCFs and 353 patients who did not. The mean age was 72.9 (standard deviation 18.3) years (range 21 to 106 yr); 349 (53.2%) were female and 118 (18.0%) were admitted to the intensive care unit. The overall mortality rate was 23.8% (156/656), but was higher among patients living in RCFs (36.6% [111/303]) compared with those not living in RCFs (12.7% [45/353]). Increased risk of death was associated with age 80 years and older (hazard ratio [HR] 2.39, 95% confidence interval [CI] 1.35-4.24), male sex (HR 1.74, 95% CI 1.25-2.41), the presence of 4 or more comorbidities (HR 2.01, 95% CI 1.18-3.42) and living in an RCF (HR 1.62, 95% CI 1.09-2.39). INTERPRETATION: During the first wave of the COVID-19 epidemic in Montréal, more than one-third of RCF residents hospitalized with SARS-CoV-2 infection died during hospitalization. Policies and practices that prevent future outbreaks of SARS-CoV-2 infection in this setting must be implemented to prevent high mortality in this vulnerable population.

Impact of extended use and decontamination with vaporized hydrogen peroxide on N95 respirator fit.

BACKGROUND: To address the shortage of N95 respirators in the wake of the COVID-19 pandemic, some organizations have recommended the decontamination of respirators using vaporized hydrogen peroxide (VHP) sterilizer for up to 10 times. However, these recommendations are based on studies that did not take into account the extended use of respirators, which can degrade respirator fit. METHODS: We investigated the impact of extended use and decontamination with VHP on N95 Respirator Fit. We performed a prospective cohort study to determine the number of times respirators can be decontaminated before respirator fit test failure. The primary outcome was the overall number of cycles required for half of the respirators to fail (either mechanical failure or fit test failure). RESULTS: Thirty-six participants completed 360 hours of respirator usage across 90 cycles. The median number of cycles completed by participants before respirator failure was 2. The overall number of cycles required for half of respirators to fail was 1, 3, 5, and 4 for the 3M 1860(S), 3M 1870+, Moldex 151X and ProGear 88020 respirators, respectively. CONCLUSIONS: The combination of prolonged usage and VHP decontamination was associated with early failure. Decontamination and prolonged usage of respirators must be done cautiously.

Progressive disseminated histoplasmosis in an apparently immunocompetent patient with a bioprosthetic aortic valve.

Histoplasma capsulatum is an endemic fungus in eastern Canada. This organism has a wide spectrum of manifestations ranging from isolated pulmonary to disseminated disease. The latter usually occurs in immunocompromised hosts or those with substantial environmental exposure. In rare instances, disseminated histoplasmosis can present as an endovascular infection or chronic progressive disseminated histoplasmosis. If not recognized, these entities are almost uniformly fatal. We report a case of an immunocompetent man with a history of longstanding constitutional symptoms. An infectious cause was initially presumed to be unlikely given the chronic nature of his presentation and an extensive series of negative investigations. A diagnosis was only obtained post-mortem upon the unusual detection of both yeast and hyphal forms in blood culture bottles inoculated with a bone marrow aspirate.

L'Histoplasma capsulatum est une mycose endémique dans l'est du Canada. Cet organisme présente un vaste spectre de manifestations, de l'atteinte pulmonaire isolée à la maladie disséminée. En général, la forme disséminée s'observe chez des hôtes immunodéprimés ou qui y ont été largement exposés dans l'environnement. Dans de rares cas, l'histoplasmose disséminée peut prendre la forme d'une infection endovasculaire ou d'une histoplasmose disséminée progressive chronique. Non diagnostiquées, ces entités sont pratiquement toujours fatales. Les auteurs déclarent le cas d'un homme ayant une histoire de symptômes constitutionnels de longue date. Au départ, la cause infectieuse était considérée comme peu probable étant donné la présentation chronique et la longue série d'explorations négatives. Le diagnostic n'a été posé qu'après le décès, lors de la détection inhabituelle des formes à levures et à mycélium dans les flacons d'hémoculture inoculés d'un aspirat de moelle osseuse.

Retrospective Cohort Study of the Prevalence of Off-label Gabapentinoid Prescriptions in Hospitalized Medical Patients.

Gabapentinoid prescriptions are increasing in North America, with frequent off-label use despite limited proven efficacy. This retrospective cohort study describes prescribing trends among hospitalized patients with a focus on dosing and deprescribing. We examined consecutive inpatients between December 2013 and July 2017 on a 52-bed medical unit in Montréal, Canada. Prevalence of off-label use, median doses prescribed, and deprescribing trends were analyzed over time. Of 4,103 hospitalized patients, 550 (13.4%) were prescribed gabapentinoids preadmission, with two patients being coprescribed gabapentin and pregabalin (total 552 prescriptions). A minority (94/552, or 17%) were for approved indications. Although it was uncommon for gabapentinoids to be newly prescribed in hospital, preadmission gabapentinoids were also seldom deprescribed (65/495 patients discharged alive, or 13%). Given a high prevalence of use, limited efficacy, and potential harms, gabapentinoids may represent an ideal target for re-evaluation of indication and effectiveness in hospitalized adults, with consideration given to deprescribing.