ABSTRACT
We evaluated the diagnostic performance of 4 commercially NAAT for detecting SARS-CoV-2 RNA, Influenza type A/B virus and RSV. Included tests were the Allplex™ SARS-CoV-2 fast PCR Assay (RNA extraction-free), Allplex™ RV Master Assay, Allplex™ SARS-CoV-2 fast MDx Assay (LAMP) and Aptima™ SARS-CoV-2/Flu Assay (RT-TMA). The assays' performance characteristics were determined using nasopharyngeal swabs from 270 patients with suspected SARS-CoV-2 infection. A total of 215 SARS-CoV-2 positive, 55 negative nasopharyngeal swabs and 19 bacteria strains were included. The sensitivities and specificities for detecting SARS-CoV-2, Influenza type A virus and RSV ranged between 81.8% and 100% with extremely good agreements (κ ≥ 86.8 %). The Aptima™ SARS-CoV-2/Flu Assay introduced a new result parameter, that is, TTime. Here, we showed that TTime may be used as a surrogate for Ct-value. We concluded that all assays assessed in this study can be used for routine detection of SARS-CoV-2, Influenza type A virus and RSV.
Subject(s)
COVID-19 , Herpesvirus 1, Cercopithecine , Influenza A virus , Influenza, Human , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Herpesvirus 1, Cercopithecine/genetics , Influenza, Human/diagnosis , RNA, Viral/genetics , Influenza A virus/genetics , Sensitivity and Specificity , Nasopharynx , COVID-19 TestingABSTRACT
OBJECTIVES: We assessed the performance of the Seegene Novaplex™ Dermatophyte Assay for diagnosis of dermatophytosis. METHODS: Sixty-one clinical samples from skin, nail, hair and culture were selected based on RT-PCR according to Wisselink et al. Of these samples, 26 samples were negative and 35 samples were positive with 39 dermatophytes strains. Emerging fungal strains harbouring terbinafine resistance (i.e. T. indotineae and T. mentagrophytes) were included. RESULTS: The specificities of the Novaplex™ Dermatophyte Assay ranged between 94.3% and 97.9%. The sensitivities for the detection of T. rubrum complex, T. mentagrophytes/T. interdigitale species complex and C. albicans were 94.1% (95% CI: 71.3-99.9), 78.6% (95% CI: 49.2-95.3) and 100% (95% CI: 69.2-100), respectively, with Cohen's kappa of at least 72.9%. CONCLUSIONS: The Seegene Novaplex™ Dermatophyte Assay can be used for reliable screening of dermatophytes, including emerging strains in a routine laboratory setting.
Subject(s)
Arthrodermataceae , Humans , Arthrodermataceae/genetics , Polymerase Chain Reaction , Sensitivity and Specificity , DNA, Fungal , Skin/microbiology , Candida albicansABSTRACT
BACKGROUND: Staphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads. METHODS: Therefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors. RESULTS: 195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001). Patients with exacerbations (n = 60), S. aureus small-colony variants (SCVs, n = 84) and co-infection with Stenotrophomonas maltophilia (n = 44) had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103). Patients with SCVs were older (p = 0.0066) and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078). IL-6 levels positively correlated with decreased lung function (p<0.001), S. aureus density in sputa (p = 0.0016), SCVs (p = 0.0209), exacerbations (p = 0.0041) and co-infections with S. maltophilia (p = 0.0195) or A. fumigatus (p = 0.0496). CONCLUSIONS: In CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia. TRIAL REGISTRATION: ClinicalTrials.gov NCT00669760.
