Pitfalls of SARS-CoV-2 antigen testing at emergency department.

BACKGROUND: Current method for diagnosis of SARS-CoV-2 infection is an RT-PCR test on the nasopharyngeal or oropharyngeal swab. Rapid diagnosis is essential for containing viral spread and triage of symptomatic patients presenting to hospital ER departments. As a faster alternative to RT-PCR, we evaluated a SARS-Cov-2 Rapid Antigen test in symptomatic patients presenting to hospital ER departments. METHODS: We evaluated the diagnostic performance of the Roche SARS-CoV-2 Rapid Antigen test (SD Biosensor) for detection of SARS-CoV-2 compared to RT-PCR. RESULTS: Our study showed inferior performance of the SARS-CoV-2 Rapid Antigen test for detection of SARS-CoV-2. Firstly, because of the lack of specificity, which is potentially life-threatening due to the association of nosocomial-acquired SARS-CoV-2 infection. Secondly, with a sensitivity of 45.5%, it is impossible to rule out SARS-CoV-2 infection, resulting in reflex PCR-testing. Comparison of viral load in RT-PCR positive samples with corresponding antigen results showed a significant difference between antigen positive and negative samples. COVID-19 infection will not be detected in patients admitted to the hospital in an early or late phase, typically associated with low viral loads. Sensitivity increases when testing within 5-7 symptomatic days, but the implementation of this cut-off is impractical in ER settings. However, diagnostic performance is better to detect high viral load (> = 5 log10 copies/mL) linked with contagiousness. CONCLUSION: Our study showed inferior performance of the Roche SARS-CoV-2 Rapid Antigen test (SD Biosensor) for detection of SARS-CoV-2 which limits its use as a diagnostic gatekeeper in ER departments, but is able to differentiate contagious individuals.

First report of a prosthetic joint infection with Fannyhessea (Atopobium) vaginae.

This case describes a 77-year-old woman with dysregulated type II diabetes, presenting with a prosthetic joint infection and bacteremia. Computed tomography (CT) of the pelvis and sacrum revealed manifest periprosthetic collections, suggestive of a septic arthritis with loosening of the hip prosthesis. Synovial fluid grew Fannyhessea vaginae, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). To our knowledge, this is the first report of a prosthetic joint infection due to this organism.

Rat bite fever: a case report review.

CONTEXT: Rat bite fever is a rare disease with a challenging differential diagnosis. The zoonosis has a potentially lethal course in a vulnerable population (children and low socioeconomic class) and a commonly available standard therapy (penicillin). This case report review outlines common epidemiological and clinical factors to improve clinical awareness and timely response to therapeutic actions. METHODS: A systematic literature review was conducted in the PubMed database looking for English language European case reports of rat bite fever from 2000 to 2021. RESULTS: In 17 out of 20 selected cases, the condition of the index patient was identified as an infectious syndrome. Thanks to the almost omnisensitive susceptibility pattern of Streptobacillus moniliformis, timely antibiotic administration prevented an unfavorable outcome in all these cases. However, in the three remaining cases, the initial diagnoses were arthritis (on autoimmune basis and gout) and viral syndrome. Due to delayed antibiotic administration, one case suffered persistent harm, while the other two cases encountered prolonged illness. CONCLUSION AND RECOMMENDATIONS: Rat bite fever is a diagnosis that can be easily missed from both a clinical and a microbiological point of view. As such, rat bite fever becomes part of the differential diagnosis whenever a patient presents with a fever syndrome after being in contact with rodents. In the case of persistent fever, blood culture sampling should be performed even in the absence of a systemic inflammatory response. A bacterial 16S ribosomal RNA PCR on blood or joint aspiration (cultures) is an even more sensitive diagnostic test. Since most transmissions occurred in a domestic setting, keeping rats as pets cannot be recommended.

Comparison of Two Commercial Colorimetric Broth Microdilution Tests for Candida Susceptibility Testing: Sensititre YeastOne versus MICRONAUT-AM.

Two colorimetric broth microdilution antifungal susceptibility tests were compared, Sensititre YeastOne and MICRONAUT-AM for nine antifungal agents. One hundred clinical Candida isolates were tested, representing a realistic population for susceptibility testing in daily practice. The reproducibility characteristics were comparable. Only for fluconazole, caspofungin, 5-flucytosine and amphotericin B, an essential agreement of ≥90% could be demonstrated. Sensititre minimal inhibitory concentrations (MICs) were systematically higher than MICRONAUT MICs for all antifungals, except for itraconazole. CLSI clinical breakpoints (CBPs) and epidemiological cut-off values (ECVs) were used for Sensititre MICs while for MICRONAUT the EUCAST CBPs and ECVs were used. Only fluconazole, micafungin, and amphotericin B had a categorical agreement of ≥90%. For fluconazole, micafungin, and amphotericin B the susceptibility proportions were comparable. Susceptibility proportion of posaconazole and voriconazole was higher using the MICRONAUT system. For itraconazole and anidulafungin, the susceptibility proportion was higher using Sensititre. It was not possible to determine the true MIC values or the correctness of a S/I/R result since both commercial systems were validated against a different reference method. These findings show that there is a significant variability in susceptibility pattern and consequently on use of antifungals in daily practice, depending on the choice of commercial system.

Distribution of HCV genotypes in Belgium from 2008 to 2015.

BACKGROUND: The knowledge of circulating HCV genotypes and subtypes in a country is crucial to guide antiviral therapy and to understand local epidemiology. Studies investigating circulating HCV genotypes and their trends have been conducted in Belgium. However they are outdated, lack nationwide representativeness or were not conducted in the general population. METHODS: In order to determine the distribution of different circulating HCV genotypes in Belgium, we conducted a multicentre study with all the 19 Belgian laboratories performing reimbursed HCV genotyping assays. Available genotype and subtype data were collected for the period from 2008 till 2015. Furthermore, a limited number of other variables were collected: some demographic characteristics from the patients and the laboratory technique used for the determination of the HCV genotype. RESULTS: For the study period, 11,033 unique records collected by the participating laboratories were used for further investigation. HCV genotype 1 was the most prevalent (53.6%) genotype in Belgium, with G1a and G1b representing 19.7% and 31.6%, respectively. Genotype 3 was the next most prevalent (22.0%). Further, genotype 4, 2, and 5 were responsible for respectively 16.1%, 6.2%, and 1.9% of HCV infections. Genotype 6 and 7 comprise the remaining <1%. Throughout the years, a stable distribution was observed for most genotypes. Only for genotype 5, a decrease as a function of the year of analysis was observed, with respectively 3.6% for 2008, 2.3% for 2009 and 1.6% for the remaining years. The overall M:F ratio was 1.59 and was mainly driven by the high M:F ratio of 3.03 for patients infected with genotype 3. Patients infected with genotype 3 are also younger (mean age 41.7 years) than patients infected with other genotypes (mean age above 50 years for all genotypes). The patients for whom a genotyping assay was performed in 2008 were younger than those from 2015. Geographical distribution demonstrates that an important number of genotyped HCV patients live outside the Belgian metropolitan cities. CONCLUSION: This national monitoring study allowed a clear and objective view of the circulating HCV genotypes in Belgium and will help health authorities in the establishment of cost effectiveness determinations before implementation of new treatment strategies. This baseline characterization of the circulating genotypes is indispensable for a continuous surveillance, especially for the investigation of the possible impact of migration from endemic regions and prior to the increasing use of highly potent direct-acting antiviral (DAA) agents.

Antitumoral activity of tyrosine kinase inhibitors in patients with non-small cell lung cancer harbouring rare epidermal growth factor receptor mutations.

INTRODUCTION: Mutations in the epidermal growth factor receptor (EGFR) have been reported as predictive markers of tumour response to tyrosine kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). Although the "common" EGFR mutations have been associated with response to EGFR-TKIs, the correlation with response to treatment for many other rare mutations is still unclear. The aim of this study was to investigate the clinical significance of rare and complex mutations, and the efficacy of EGFR-TKIs in this selected group of patients. METHODS: Three hundred and thirty patients with stage IIIB/IV NSCLC (106 females aged 62.5 ± 1.1 years; 224 males aged 68.0 ± 0.6 years) were enrolled in the study. Formalin fixed paraffin embedded tissue samples were screened for mutations using a high resolution melting technique, followed by Sanger sequencing of exons 18-21 of the EGFR-gene. Mutation status was also tested using the Roche Cobas(®) EGFR mutation test. RESULTS: EGFR mutations were detected in 31 tumours (9.4 %). Eleven cases carried novel mutations, six of these patients were treated with erlotinib or gefitinib. A response rate (RR) of 50.0 % was obtained in the group with rare EGFR mutations, the PFS was 3.0 months [standard deviation (STD) = 5.4 months]. The RR to EGFR-TKIs in patients with conventional EGFR mutations was 85 % with a median PFS of 10.5 months (STD = 3.6 months). CONCLUSION: We reported six patients with rare EGFR mutations of unknown clinical significance and their association with EGFR-TKIs. Report of cases harbouring rare mutations can support the decision making progress in this subset of patients.

Epidemiology of invasive aspergillosis in critically ill patients: clinical presentation, underlying conditions, and outcomes.

INTRODUCTION: Invasive aspergillosis (IA) is a fungal infection that particularly affects immunocompromised hosts. Recently, several studies have indicated a high incidence of IA in intensive care unit (ICU) patients. However, few data are available on the epidemiology and outcome of patients with IA in this setting. METHODS: An observational study including all patients with a positive Aspergillus culture during ICU stay was performed in 30 ICUs in 8 countries. Cases were classified as proven IA, putative IA or Aspergillus colonization according to recently validated criteria. Demographic, microbiologic and diagnostic data were collected. Outcome was recorded 12 weeks after Aspergillus isolation. RESULTS: A total of 563 patients were included, of whom 266 were colonized (47%), 203 had putative IA (36%) and 94 had proven IA (17%). The lung was the most frequent site of infection (94%), and Aspergillus fumigatus the most commonly isolated species (92%). Patients with IA had higher incidences of cancer and organ transplantation than those with colonization. Compared with other patients, they were more frequently diagnosed with sepsis on ICU admission and more frequently received vasopressors and renal replacement therapy (RRT) during the ICU stay. Mortality was 38% among colonized patients, 67% in those with putative IA and 79% in those with proven IA (P < 0.001). Independent risk factors for death among patients with IA included older age, history of bone marrow transplantation, and mechanical ventilation, RRT and higher Sequential Organ Failure Assessment score at diagnosis. CONCLUSIONS: IA among critically ill patients is associated with high mortality. Patients diagnosed with proven or putative IA had greater severity of illness and more frequently needed organ support than those with Aspergillus spp colonization.

Atopobium deltae sp. nov., isolated from the blood of a patient with Fournier's gangrene.

A Gram-stain-positive, obligately anaerobic, short rod, designated strain HHRM1715(T), was isolated from the blood of a patient with Fournier's gangrene, complicated by sepsis. On the basis of 16S rRNA gene sequence analysis, strain HHRM1715(T) was shown to belong to the genus Atopobium and was most closely related to Atopobium minutum (95 % similarity). The results of 16S rRNA-gene-based phylogenetic analysis, cellular fatty acid analysis and differential biochemical tests, showed that strain HHRM1715(T) represented a novel species of the genus Atopobium. We therefore describe Atopobium deltae sp. nov. with HHRM1715(T) ( = LMG 27987(T) = CCUG 65171(T)) as the type strain and propose an emended description of the genus Atopobium with regard to the DNA G+C content.

Sepsis with an Atopobium-like species in a patient with Fournier's gangrene.

Atopobium species are Gram-positive, anaerobic, catalase-negative, fastidious bacteria belonging to the family Coriobacteriaceae. We report the isolation of an Atopobium-like species in a patient with Fournier's gangrene and highlight the role of 16S rRNA gene sequencing in the identification of fastidious organisms in the clinical laboratory.

First case of Pseudoclavibacter bifida bacteremia in an immunocompromised host with chronic obstructive pulmonary disease (COPD).

Pseudoclavibacter spp. are Gram-positive, aerobic, catalase-positive, coryneform bacteria belonging to the family of Microbacteriaceae. Identification of these species with conventional biochemical assays is difficult. This case report of a Pseudoclavibacter bifida bacteremia occurring in an immunocompromised host diagnosed with an acute exacerbation of chronic obstructive pulmonary disease, with a lethal outcome, confirms that this organism may be a human pathogen.

A case of Candida lambica fungemia misidentified as Candida krusei in an intravenous drug abuser.

Only a handful of cases of human Candida lambica infections have been published up to now. We report a Candida lambica fungemia in a young intravenous drug abuser. Using a popular chromogenic agar and a commercial phenotyping gallery, the fungus was initially misidentified as Candida krusei. Key tests to distinguish these closely related species are maximum growth temperature and assimilation of certain substrates present in more elaborate phenotyping assays. Definite confirmation is possible using molecular techniques. Susceptibility testing of the isolate demonstrated amphotericin B (MIC 0.125 microg/ml) susceptible, flucytosine (MIC 2 microg/ml) susceptible, itraconazole (MIC 0.064 microg/ml) susceptible, voriconazole (MIC 1 microg/ml) susceptible, and fluconazole (MIC >64 microg/ml, resistant).

Alternaria infectoria phaeohyphomycosis in a renal transplant patient.

A male renal transplant patient developed a tumor on the dorsum of his right hand. After excision, histological examination of the tumor showed hyphal structures, but growth developed very slowly. Therapy consisted of surgery alone. A definitive identification of Alternaria infectoria was only possible with molecular techniques.