Timing and Predictors of Loss of Infectivity Among Healthcare Workers With Mild Primary and Recurrent COVID-19: A Prospective Observational Cohort Study.

BACKGROUND: There is a need to understand the duration of infectivity of primary and recurrent coronavirus disease 2019 (COVID-19) and identify predictors of loss of infectivity. METHODS: Prospective observational cohort study with serial viral culture, rapid antigen detection test (RADT) and reverse transcription polymerase chain reaction (RT-PCR) on nasopharyngeal specimens of healthcare workers with COVID-19. The primary outcome was viral culture positivity as indicative of infectivity. Predictors of loss of infectivity were determined using multivariate regression model. The performance of the US Centers for Disease Control and Prevention (CDC) criteria (fever resolution, symptom improvement, and negative RADT) to predict loss of infectivity was also investigated. RESULTS: In total, 121 participants (91 female [79.3%]; average age, 40 years) were enrolled. Most (n = 107, 88.4%) had received ≥3 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine doses, and 20 (16.5%) had COVID-19 previously. Viral culture positivity decreased from 71.9% (87/121) on day 5 of infection to 18.2% (22/121) on day 10. Participants with recurrent COVID-19 had a lower likelihood of infectivity than those with primary COVID-19 at each follow-up (day 5 odds ratio [OR], 0.14; P < .001]; day 7 OR, 0.04; P = .003]) and were all non-infective by day 10 (P = .02). Independent predictors of infectivity included prior COVID-19 (adjusted OR [aOR] on day 5, 0.005; P = .003), an RT-PCR cycle threshold [Ct] value <23 (aOR on day 5, 22.75; P < .001) but not symptom improvement or RADT result.The CDC criteria would identify 36% (24/67) of all non-infectious individuals on day 7. However, 17% (5/29) of those meeting all the criteria had a positive viral culture. CONCLUSIONS: Infectivity of recurrent COVID-19 is shorter than primary infections. Loss of infectivity algorithms could be optimized.

Persistence of infectivity in elderly individuals diagnosed with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection 10 days after onset of symptoms: A cross-sectional study.

We performed viral culture of nasopharyngeal specimens in individuals aged 79 and older, infected with severe acute respiratory coronavirus virus 2 (SARS-CoV-2), 10 days after symptom onset. A positive viral culture was obtained in 10 (45%) of 22 participants, including 4 (33%) of 12 individuals with improving symptoms. The results of this small study suggest that infectivity may be prolonged among older individuals.

Medical Masks Versus N95 Respirators for Preventing COVID-19 Among Health Care Workers : A Randomized Trial.

BACKGROUND: It is uncertain if medical masks offer similar protection against COVID-19 compared with N95 respirators. OBJECTIVE: To determine whether medical masks are noninferior to N95 respirators to prevent COVID-19 in health care workers providing routine care. DESIGN: Multicenter, randomized, noninferiority trial. (ClinicalTrials.gov: NCT04296643). SETTING: 29 health care facilities in Canada, Israel, Pakistan, and Egypt from 4 May 2020 to 29 March 2022. PARTICIPANTS: 1009 health care workers who provided direct care to patients with suspected or confirmed COVID-19. INTERVENTION: Use of medical masks versus fit-tested N95 respirators for 10 weeks, plus universal masking, which was the policy implemented at each site. MEASUREMENTS: The primary outcome was confirmed COVID-19 on reverse transcriptase polymerase chain reaction (RT-PCR) test. RESULTS: In the intention-to-treat analysis, RT-PCR-confirmed COVID-19 occurred in 52 of 497 (10.46%) participants in the medical mask group versus 47 of 507 (9.27%) in the N95 respirator group (hazard ratio [HR], 1.14 [95% CI, 0.77 to 1.69]). An unplanned subgroup analysis by country found that in the medical mask group versus the N95 respirator group RT-PCR-confirmed COVID-19 occurred in 8 of 131 (6.11%) versus 3 of 135 (2.22%) in Canada (HR, 2.83 [CI, 0.75 to 10.72]), 6 of 17 (35.29%) versus 4 of 17 (23.53%) in Israel (HR, 1.54 [CI, 0.43 to 5.49]), 3 of 92 (3.26%) versus 2 of 94 (2.13%) in Pakistan (HR, 1.50 [CI, 0.25 to 8.98]), and 35 of 257 (13.62%) versus 38 of 261 (14.56%) in Egypt (HR, 0.95 [CI, 0.60 to 1.50]). There were 47 (10.8%) adverse events related to the intervention reported in the medical mask group and 59 (13.6%) in the N95 respirator group. LIMITATION: Potential acquisition of SARS-CoV-2 through household and community exposure, heterogeneity between countries, uncertainty in the estimates of effect, differences in self-reported adherence, differences in baseline antibodies, and between-country differences in circulating variants and vaccination. CONCLUSION: Among health care workers who provided routine care to patients with COVID-19, the overall estimates rule out a doubling in hazard of RT-PCR-confirmed COVID-19 for medical masks when compared with HRs of RT-PCR-confirmed COVID-19 for N95 respirators. The subgroup results varied by country, and the overall estimates may not be applicable to individual countries because of treatment effect heterogeneity. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research, World Health Organization, and Juravinski Research Institute.

Low-dose trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia (LOW-TMP): protocol for a phase III randomised, placebo-controlled, dose-comparison trial.

INTRODUCTION: Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection of immunocompromised hosts with significant morbidity and mortality. The current standard of care, trimethoprim-sulfamethoxazole (TMP-SMX) at a dose of 15-20 mg/kg/day, is associated with serious adverse drug events (ADE) in 20%-60% of patients. ADEs include hypersensitivity reactions, drug-induced liver injury, cytopenias and renal failure, all of which can be treatment limiting. In a recent meta-analysis of observational studies, reduced dose TMP-SMX for the treatment of PJP was associated with fewer ADEs, without increased mortality. METHODS AND ANALYSIS: A phase III randomised, placebo-controlled, trial to directly compare the efficacy and safety of low-dose TMP-SMX (10 mg/kg/day of TMP) with the standard of care (15 mg/kg/day of TMP) among patients with PJP, for a composite primary outcome of change of treatment, new mechanical ventilation, or death. The trial will be undertaken at 16 Canadian hospitals. Data will be analysed as intention to treat. Primary and secondary outcomes will be compared using logistic regression adjusting for stratification and presented with 95% CI. ETHICS AND DISSEMINATION: This study has been conditionally approved by the McGill University Health Centre; Ethics approval will be obtained from all participating centres. Results will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT04851015.

Covid-19 vaccine acceptance, hesitancy, and refusal among Canadian healthcare workers: A multicenter survey.

BACKGROUND: Determinants of COVID-19 vaccine acceptance among healthcare workers (HCW) remains poorly understood. We assessed HCWs' willingness to be vaccinated and reasons underlying hesitancy. METHODS: Cross-sectional survey across 17 healthcare institutions. HCWs eligible for vaccination (Pfizer-BioNTech mRNA) in December 2020 were invited to receive immunization. Multivariate logistic regression was performed to identify predictors of acceptance. Reasons for refusal among those who never intended to be vaccinated (ie, firm refusers) and those who preferred delaying vaccination (ie, vaccine hesitants) were assessed. RESULTS: Among 2,761 respondents (72% female, average age, 44), 2,233 (80.9%) accepted the vaccine. Physicians, environmental services workers and healthcare managers were more likely to accept vaccination compared to nurses. Male sex, age over 50, rehabilitation center workers, and occupational COVID-19 exposure were independently associated with vaccine acceptance by multivariate analysis. Factors for refusal included vaccine novelty, wanting others to receive it first, and insufficient time for decision-making. Among those who declined, 74% reported they may accept future vaccination. Vaccine firm refusers were more likely than vaccine hesitants to distrust pharmaceutical companies and to prefer developing a natural immunity by getting COVID-19. CONCLUSIONS: Vaccine hesitancy exists among HCWs. Our findings provide useful information to plan future interventions and improve acceptance.

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.

Prevalence of Auto-antibodies in Pulmonary Tuberculosis.

The relationship between pulmonary tuberculosis and auto-antibodies remains undefined. In a study of 75 patients with pulmonary tuberculosis and 75 controls, the prevalence of auto-antibodies was assessed in a reference laboratory using a comprehensive panel with standardized methodology. No significant relationship was found between auto-antibody prevalence and pulmonary tuberculosis.

Switching from expectorated to induced sputum cultures for tuberculosis diagnosis reduces cost without increasing risk.

Active pulmonary tuberculosis testing with 3 expectorated sputa can increase isolation days and expenditures compared with 1 induced sputum. Six-month retrospective and prospective chart reviews were conducted, and a screening algorithm was phased into 2 hospital sites. With induced sputum testing, isolation decreased from 7 to 4 days (interquartile range, 4-3, P = .0135), and there was a cost savings of $7,275 per case, with no added harm.

The Efficacy of Computed Tomography-Guided Percutaneous Spine Biopsies in Determining a Causative Organism in Cases of Suspected Infection: A Systematic Review.

PURPOSE: In suspected spondylodiscitis and vertebral osteomyelitis, computed tomography (CT)-guided biopsies are often performed to determine a causative organism and guide antimicrobial therapy. The aim of this study is to determine the diagnostic culture yield of CT-guided biopsies performed in cases of suspected spinal infections. METHODS: A literature search of PubMed and MEDLINE up to April 2017 was performed for keywords "CT guided vertebral biopsy infection," "CT-guided spine biopsy infection," "CT guided spine biopsy yield," and "CT guided vertebral biopsy yield." Inclusion criteria primarily consisted of studies exclusively using CT-guided biopsies in cases of suspected infectious lesions only. After study selection, published articles were analysed to determine diagnostic culture yield. Descriptive statistics were applied. RESULTS: 220 search results were screened; 11 met our inclusion criteria and were reviewed. In total, 647 biopsies of suspected infectious spinal lesions were performed. Positive cultures were obtained in 241 cases. Upon excluding one paper's skewed results, the net pooled results culture yield was 33%. Several cultures grew multiple organisms, leading to a total of 244 species identified. Most common isolated organisms include Staphylococcus aureus (n = 83), coagulase-negative Staphylococcus (n = 45), and Mycobacteria (n = 38). CONCLUSIONS: The diagnostic culture yield of CT-guided biopsies in cases of suspected spinal infection is 33%. In the majority of cases, a causative organism is not identified. This suggests that improvements can be made in biopsy technique and specimen transfer to optimize culture yield and increase the clinical value of the procedure.

Sink-Related Outbreaks and Mitigation Strategies in Healthcare Facilities.

PURPOSE OF REVIEW: In this review, we summarize recent outbreaks attributed to hospital sinks and examine design features and behaviors that contributed to these outbreaks. The effectiveness of various risk mitigation strategies is presented. Finally, we examine investigational strategies targeted at reducing the risk of sink-related infections. RECENT FINDINGS: Outbreaks of hospital sink-related infections involve a diverse spectrum of microorganisms. They can be attributed to defects in sink design and hospital wastewater systems that promote the formation and dispersion of biofilm, as well as healthcare practitioner and patient behaviors. Risk mitigation strategies are often bundled; while they may reduce clinical cases, sink colonization may persist. Novel approaches targeting biofilms show promise but require more investigation. Emphasis should be placed on optimizing best practices in sink design and placement to prevent infections. Hospitals should consider developing a rational surveillance and prevention strategy based on the current design and state of their sinks.

A Cluster of Three Cases of Hantavirus Pulmonary Syndrome among Canadian Military Personnel.

Hantavirus pulmonary syndrome (HPS) is a rare illness in eastern Canada. We present three cases of HPS among military personnel in Quebec. The three cases shared a common exposure to mouse excreta while engaged in military training in Alberta, a western province of Canada.