Duration of isolation and contagiousness in coronavirus disease 2019 (COVID-19) patients receiving tocilizumab and dexamethasone: A case series.

We describe 10 patients with severe coronavirus disease 2019 (COVID-19) who received tocilizumab and dexamethasone. We correlated isolation duration with cycle thresholds (Ct) values of nucleic acid amplification tests, clinical state and viral cultures. Isolation duration exceeded 21 days for 7 patients due to positive viral cultures or Ct values <30.

Arrival of the rare carbapenemase OXA-204 in Canada causing a multispecies outbreak over 3 years.

OBJECTIVES: To investigate a persistent multispecies OXA-204 outbreak occurring simultaneously in multiple distant hospitals in the province of Quebec, Canada. METHODS: OXA-204 carbapenemase-producing Enterobacterales (CPE) isolated from multiple hospitals between January 2016 and October 2018 were included in the study. An epidemiological inquiry was conducted in order to elucidate possible transmission routes and a putative source. Isolates were characterized by standardized antibiotic susceptibility testing and by WGS, using Illumina short-read data and MinION long-read data. RESULTS: The outbreak comprised 65 patients and 82 isolates from four hospital sites. Most patients were ≥65 years old, had multiple comorbidities and had received antibiotics recently. The infection to colonization ratio was 1:20. No persistent environmental reservoir was identified. The most frequent organism was Citrobacter freundii (n = 78), followed by Klebsiella spp. (n = 3) and Escherichia coli (n = 1). WGS analysis showed 77/78 C. freundii isolates differing by 0-26 single nucleotide variants (SNVs). Results of WGS analysis showed blaOXA-204 was present on three plasmids types (IncX1, IncA/C2 and IncFII/FIB/A/C2) and on a prophage. All C. freundii isolates harboured multiple copies of blaOXA-204, both on the chromosome and a plasmid. Plasmid IncFII/FIB/A/C2 was observed in all three species. CONCLUSIONS: Transfer of OXA-204 plasmids likely occurred between species within the same patient, highlighting the plasticity of these plasmids and potential for widespread dissemination. OXA-204 carbapenemase has been introduced into Quebec and has rapidly disseminated. Although the infection to colonization ratio was low in this outbreak, this carbapenemase has been associated with severe infection elsewhere.

Methicillin-resistant Staphylococcus aureus colonization among medical residents.

BACKGROUND: Medical residents may be at risk of becoming colonized by methicillin-resistant Staphylococcus aureus (MRSA) during their training. The occupational risk of this specific population is unknown. Furthermore, there are no data regarding MRSA colonization among health care professionals in Quebec. OBJECTIVE: To determine the MRSA colonization rate in Laval University (Quebec City, Quebec) medical residents and compare it with the MRSA colonization rate of a control group. METHODS: A controlled cross-sectional study of MRSA prevalence among medical residents of Laval University was performed. The control group consisted of Laval University undergraduate medical students without previous clinical rotations in their curriculum. After informed consent was obtained, participants were screened for MRSA with a nasal swab in both anterior nares. They also completed a questionnaire regarding relevant risk factors and demographic data. RESULTS: A total of 250 residents of all residency levels from medical and surgical specialties and 247 controls were recruited between February and April 2010. One case of MRSA colonization was detected among the residents and none in the control group (prevalence of 0.4% versus 0.0%; P=1.00). DISCUSSION: MRSA nasal carriage was very low among Laval University residents. This may reflect the decreasing rate of health care-associated MRSA in Quebec City. Young age and good health may also explain this low risk. The strict infection control policies for MRSA patients (including cohorting, use of gloves, gown and patient-dedicated equipment) may also contribute to prevent MRSA transmission. CONCLUSIONS: Medical residents in Quebec City appeared to be at very low risk of contracting MRSA through professional activities.

HISTORIQUE: Les résidents en médecine peuvent être à risque d'être colonisés par le Staphylococcus aureus résistant à la méthicilline (SARM) pendant leur formation. On ne connaît pas le risque professionnel de cette population. De plus, il n'existe pas de données sur la colonisation par le SARM des professionnels de la santé au Québec. OBJECTIF: Déterminer le taux de colonisation par le SARM des résidents en médecine de l'Université Laval (de Québec, au Québec) et le comparer à celui d'un groupe témoin. MÉTHODOLOGIE: Les chercheurs ont mené une étude transversale contrôlée de la prévalence du SARM chez les résidents en médecine de l'Université Laval. Le groupe témoin se composait d'étudiants en médecine non spécialisés de l'Université Laval qui n'avaient pas encore fait de rotations cliniques dans leur cursus. Après avoir donné leur consentement éclairé, les participants ont subi un test de dépistage du SARM au moyen d'un prélèvement dans les deux narines. Ils ont également rempli un questionnaire au sujet des facteurs de risque pertinents et des données démographiques. RÉSULTATS: Au total, les chercheurs ont recruté 250 résidents de toutes les années de résidence en spécialité de la médecine et de la chirurgie et 247 sujets témoins entre février et avril 2010. Ils ont dépisté un cas de colonisation par le SARM chez les résidents et n'en ont trouvé aucun dans le groupe témoin (prévalence de 0,4 % par rapport à 0,0 %; P=1,00). EXPOSÉ: Le portage nasal du SARM était très faible chez les résidents de l'Université Laval. Ce constat peut refléter le taux décroissant de SARM associés aux soins de santé dans la ville de Québec. Un jeune âge et une bonne santé peuvent également expliquer ce faible risque. Les politiques de contrôle des infections rigoureuses liées aux patients ayant un SARM (y compris le regroupement en cohortes, le port des gants et l'utilisation d'une blouse et de matériel réservés au patient) peuvent également contribuer à prévenir la transmission du SARM. CONCLUSIONS: Les résidents en médecine de la ville de Québec semblaient très peu à risque de contracter un SARM à cause de leurs activités professionnelles.

Genetic polymorphisms and drug susceptibility in four isolates of Leishmania tropica obtained from Canadian soldiers returning from Afghanistan.

BACKGROUND: Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease characterized by the presence of one or more lesions on the skin that usually heal spontaneously after a few months. Most cases of CL worldwide occur in Southwest Asia, Africa and South America, and a number of cases have been reported among troops deployed to Afghanistan. No vaccines are available against this disease, and its treatment relies on chemotherapy. The aim of this study was to characterize parasites isolated from Canadian soldiers at the molecular level and to determine their susceptibility profile against a panel of antileishmanials to identify appropriate therapies. METHODOLOGY/PRINCIPAL FINDINGS: Parasites were isolated from skin lesions and characterized as Leishmania tropica based on their pulsed field gel electrophoresis profiles and pteridine reductase 1 (PTR1) sequences. Unusually high allelic polymorphisms were observed at several genetic loci for the L. tropica isolates that were characterized. The drug susceptibility profile of intracellular amastigote parasites was determined using an established macrophage assay. All isolates were sensitive to miltefosine, amphotericin B, sodium stibogluconate (Pentostam) and paromomycin, but were not susceptible to fluconazole. Variable levels of susceptibility were observed for the antimalarial agent atovaquone/proguanil (Malarone). Three Canadian soldiers from this study were successfully treated with miltefosine. CONCLUSIONS/SIGNIFICANCE: This study shows high heterogeneity between the two L. tropica allelic versions of a gene but despite this, L. tropica isolated from Afghanistan are susceptible to several of the antileishmanial drugs available.

The value of pretest probability and modified clinical pulmonary infection score to diagnose ventilator-associated pneumonia.

PURPOSE: The aim of the study was to assess the utility of pretest probability and modified clinical pulmonary infection score CPIS in the diagnosis of late-onset ventilator-associated pneumonia (VAP). MATERIALS AND METHODS: In 740 adults enrolled in a multicenter randomized trial, intensivists prospectively rated the pretest probability of VAP as low, moderate, or high based on their clinical judgment. The modified CPIS was calculated without considering culture results. Ventilator-associated pneumonia diagnosis was determined by 2 adjudicators using standardized definitions. We analyzed the relationship between pretest likelihood, CPIS, and VAP diagnosis. RESULTS: Among the 739 patients analyzed, 14.5%, 39.6%, and 45.9% had low, moderate, and high pretest probability of VAP. Patients with high pretest probability had a lower PaO2/FiO2 ratio and a larger volume of secretions. High or moderate vs low pretest probability had high sensitivity (0.88; 95% confidence interval [CI], 0.87-0.89) and positive predictive value (0.87; 95% CI, 0.86-0.88) but low specificity (0.27; 95% CI, 0.21-0.35) and negative predictive value (0.29; 95% C,: 0.22-0.37) for the diagnosis of VAP. Therefore, 71% of patients who had a low pretest probability were actually infected (1 - negative predictive value). The area under the receiver operating characteristic curve for the modified CPIS was not significant (0.47; 95% CI, 0.42-0.53), meaning that no score threshold was clinically useful. CONCLUSIONS: Pretest probability and a modified CPIS, which excludes culture results, are of limited utility in the diagnosis of late-onset VAP.

Oral decontamination for prevention of pneumonia in mechanically ventilated adults: systematic review and meta-analysis.

OBJECTIVE: To evaluate the effect of oral decontamination on the incidence of ventilator associated pneumonia and mortality in mechanically ventilated adults. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline, Embase, CINAHL, the Cochrane Library, trials registers, reference lists, conference proceedings, and investigators in the specialty. REVIEW METHODS: Two independent reviewers screened studies for inclusion, assessed trial quality, and extracted data. Eligible trials were randomised controlled trials enrolling mechanically ventilated adults that compared the effects of daily oral application of antibiotics or antiseptics with no prophylaxis. RESULTS: 11 trials totalling 3242 patients met the inclusion criteria. Among four trials with 1098 patients, oral application of antibiotics did not significantly reduce the incidence of ventilator associated pneumonia (relative risk 0.69, 95% confidence interval 0.41 to 1.18). In seven trials with 2144 patients, however, oral application of antiseptics significantly reduced the incidence of ventilator associated pneumonia (0.56, 0.39 to 0.81). When the results of the 11 trials were pooled, rates of ventilator associated pneumonia were lower among patients receiving either method of oral decontamination (0.61, 0.45 to 0.82). Mortality was not influenced by prophylaxis with either antibiotics (0.94, 0.73 to 1.21) or antiseptics (0.96, 0.69 to 1.33) nor was duration of mechanical ventilation or stay in the intensive care unit. CONCLUSIONS: Oral decontamination of mechanically ventilated adults using antiseptics is associated with a lower risk of ventilator associated pneumonia. Neither antiseptic nor antibiotic oral decontamination reduced mortality or duration of mechanical ventilation or stay in the intensive care unit.

Comparison of the Directigen flu A+B test, the QuickVue influenza test, and clinical case definition to viral culture and reverse transcription-PCR for rapid diagnosis of influenza virus infection.

The diagnostic performances of the clinical case definition of influenza virus infection based on the combination of fever and cough and of two rapid influenza diagnostic tests, the Directigen Flu A+B test (Directigen; BD Diagnostic Systems, Sparks, Md.) and the QuickVue influenza test (QuickVue; Quidel, San Diego, Calif.), were compared to those of viral culture and an in-house reverse transcription (RT)-PCR during the 2000-2001 flu season. Two hundred consecutive nasopharyngeal aspirates were analyzed from 192 patients, including 122 adults and 70 children. Viral culture identified influenza virus A in 16 samples and influenza virus B in 55 samples, whereas RT-PCR identified influenza virus A in 21 samples and influenza virus B in 64 samples. When RT-PCR was used as the reference standard, the likelihood ratios for a positive test were 40.0 for Directigen, 8.6 for QuickVue, and 1.4 for the combination of fever and cough, whereas the likelihood ratios for a negative test were 0.22, 0.16, and 0.48, respectively. Our study suggests that (i). the poor specificity (35 to 58%) and the poor positive predictive value (41 to 60%) of the clinical case definition of influenza preclude its use for prediction of influenza virus infections during epidemics, especially when infection control decision making in the hospital setting is considered; (ii). Directigen has a higher diagnostic yield than QuickVue but is associated with a larger number of invalid results; (iii). the sensitivities of the rapid diagnostic tests are significantly lower with samples from adults than with samples from children, with the rates of false-negative results reaching up to 29%; and (iv). RT-PCR detects more cases of influenza than viral culture, and this greater accuracy makes it a more useful reference standard.