Evaluation of the performance of a rapid antigen test (Roche) for COVID-19 diagnosis in an emergency setting in Sweden.

During the ongoing COVID-19 pandemic, rapid and reliable detection of SARS-CoV-2 is important to enable proper care of patients and to prevent further transmission. The aim of this study was to evaluate the performance of the Roche SARS-CoV-2 Rapid Antigen Test (Ag-RDT) in an emergency care setting during a high pandemic period. The analytical performance of the Ag-RDT was compared to real-time reverse transcriptase polymerase chain reaction (rRT-PCR). A total of 132 patient samples, previously analyzed with rRT-PCR, were reanalyzed with the Ag-RDT. Tenfold serial dilutions of five different patient strains containing the pangolin variants BA.1, BA.2, B.1.1.7, B.1.160, and B.1.177 were analyzed in parallel with the Ag-RDT and rRT-PCR. A clinical evaluation was performed in which 1911 consecutive patients admitted to the emergency wards in Region Gävleborg, Sweden, were included. Paired samples were collected and analyzed with the Ag-RDT on-site and with rRT-PCR at the microbiology laboratory. The overall sensitivity and specificity of the Ag-RDT in the clinical evaluation were 71.3% and 99.7%, respectively. When samples with cycle threshold (Ct) values above 30 were excluded, the sensitivity was 86.5%. Eleven of the admitted patients who were positive for both the Ag-RDT and rRT-PCR (Ct-range 16.9-30.4) showed no symptoms of COVID-19. Using the Ag-RDT shortened the detection time by an average of 11 h. The Ag-RDT is a useful tool for preliminary screening of SARS-CoV-2 because it enables rapid detection in infectious individuals and therefore, can counteract unnecessary spread of infection at an early stage.

Changes in testing and incidence of Chlamydia trachomatis and Neisseria gonorrhoeae - the possible impact of the COVID-19 pandemic in the three Scandinavian countries.

BACKGROUND: This study aimed to investigate what impact the COVID-19 pandemic and its associated restrictions had on Chlamydia trachomatis and Neisseria gonorrhoeae infections in Sweden, Denmark and Norway, countries with very different governmental strategies for handling this pandemic. METHODS: Retrospective analysis of data collected via requests to Swedish regions and to health authorities in Denmark and Norway. The data were collected for the years 2018-2020 and the data from Sweden were more detailed. RESULTS: When the pandemic restrictions were installed in 2020, the number of reported chlamydia cases decreased. The decline was most pronounced in Norway 10.8% (2019: n = 28,446; 2020: n = 25,444) while it was only 3.1% in Denmark (2019: n = 35,688; 2020: n = 34,689) and 4.3% in Sweden (2019: n = 34,726; 2020: n = 33,339). Nucleic acid amplifications tests for chlamydia decreased in Sweden (10%) and Norway (18%) in 2020 compared to 2019, while in Denmark a 21% decrease was noted in April 2020 but thereafter increased to a higher level than 2019. The number of reported gonorrhoea cases decreased in Sweden (17%) and in Norway (39%) in 2020 compared to 2019, while a 21% increase was noted in Denmark. CONCLUSIONS: Pandemic restrictions had an impact on the number of reported chlamydia infections in all three countries, but only temporarily and did not seem to be correlated to the restriction levels. The number of reported gonorrhoea infections in Sweden and Norway significantly decreased but not in Denmark. Pandemic restrictions appear to have had a limited effect on the spread of chlamydia and gonorrhoea.