Introduction. COVID-19 pandemic threatens global human health. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is a reference test for identification of acute SARS-CoV-2 infection, but it is associated with results delay. There is a need of fast and reliable tests which can improve the efforts of controlling the transmission of SARS-CoV-2. Aim. The aim of this study was to determine the analytical value of the rapid SARS-CoV-2 Ag-test in relation to the Ct values of the RT-qPCR. Methods. The study group comprised outpatients suspected for COVID-19, sampled twice, first for the routine RT-qPCR, and second for SARS-CoV-2 antigen testing. The results obtained by the rapid antigen test (Panbio™ COVID-19) were evaluated in relation to Ct values of the SARS-CoV-2 E-gene, obtained by RTqPCR Allplex 19-nCoV multiplex assay platform. Results. SARS-CoV-2 prevalence, based on RT-qPCR, was 50.8% (186/366). Specificity of the PanbioTM COVID- 19 Ag Rapid Test was 100%. Test sensitivity was 73.8%. Restricting RT-qPCR to Ct-values<30 increased test sensitivity to 91.2%. Conclusion. The findings underscored the epidemiological value of the rapid Ag-test since it reliably identifies contagious SARS-CoV-2 infected individuals who actively spread the virus in the community.

Abstract Rapid SARS-CoV-2 antigen testing compared with RT-qPCR in patients suspected for COVID-19 Introduction: COVID-19 pandemic threatens global human health. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is a reference test for identification of acute SARS-CoV-2 infection, but it is associated with results delay. There is a need of a fast and reliable tests which can improve the efforts of controlling the transmission of SARS-CoV-2. Aim: This work aims to determine the analytical value of the rapid SARS-CoV-2 Ag-test in relation to the Ct values of the RT-qPCR. Methods: Study group were outpatients suspected for COVID-19, sampled twice, first for the routine RT-qPCR, and second for SARS-CoV-2 antigen testing. The results obtained by the rapid antigen test (Panbio™ COVID-19) were evaluated in relation to the Ct values of the SARS-CoV-2 E-gene, obtained by RT-qPCR Allplex 19-nCoV multiplex assay platform. Results: SARS-CoV-2 prevalence, based on RT-qPCR, was 50.8% (186/366). Specificity of the PanbioTM COVID-19 Ag Rapid Test was 100%. Test sensitivity was 73.8%. Restricting RT-qPCR to Ct-values < 30 increased test sensitivities to 91.2%. Conclusion: The findings underscored the epidemiological value of the rapid Ag-test, since it reliably identifies contagious SARS-CoV-2 infected individuals who actively spread the virus in the community.

BACKGROUND: The clinical relevance of specimens from the lower airways is often debatable. However, they are most commonly examined for diagnosing lower respiratory tract infections (LRTIs). AIM: This study aimed to determine the diagnostic value of sputum quality assessment about sputum culture for diagnosing LRTIs in children. METHODS: In six months, a total of 1485 sputum samples were quality assessed by using Bartlett’s grading system. All samples, regardless of their quality, were cultured, identified, and antimicrobial susceptibility testing was performed by Kirby-Bauer disc-diffusion method. RESULTS: Among the acceptable category, defined by Bartlett’s grading system, 132 (63.2%) samples showed culture positivity of which Streptococcus pneumoniae 48 (36.4%) was most commonly isolated, followed by Moraxella catarrhalis 22 (16.7%) and Haemophilus influenza 21 (15.9%). Among the non-acceptable category, 185 (14.5%) samples were culture positive of which most commonly isolated were Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa with 64 (34.6%), 54 (29.2%) and 28 (15.1%), respectively. CONCLUSION: Sputum quality assessment is a useful tool for distinguishing the true respiratory pathogens from possible colonising flora for which antibiotic treatment should not be highly considered. Keywords: Sputum culture, Quality assessment, Streptococcus pneumoniae, Escherichia coli