ABSTRACT
IntroductionDuring the COVID-19 pandemic, SARS-CoV-2 antigen rapid detection tests (RDTs) emerged as point-of-care diagnostics in addition to the RT-qPCR as the gold standard for SARS-CoV-2 diagnostics. Facing the course of the COVID-19 pandemic to an endemic characterised by several SARS-CoV-2 virus variants of concern (VOC) and an increasing public COVID-19 vaccination rate the aim of the study was to investigate the long-term test performance of SARS-CoV-2 RDT in large-scale, clinical screening use during and its influencing factors, above all SARS-CoV-2 VOC and COVID-19 vaccination. MethodsIn a prospective performance assessment conducted at a single centre tertiary care hospital, RDTs from three manufacturers (NADAL(R), Panbio, MEDsan(R)) were compared to RT-qPCR among individuals aged [≥] 6 month. The evaluation involved the determination of standardised viral load from oropharyngeal swabs as well as the evaluation of their influencing factors, especially the COVID-19 vaccination, for detecting SARS-CoV-2 in a clinical point-of-care environment spanning from 12 November 2020 to 30 June 2023 among patients, staff, and visitors of the hospital. ResultsAmong the 78,798 RDT/RT-qPCR tandems analysed, 2,016 (2.6%) tandems tested positive for SARS-CoV-2, with an overall sensitivity of 34.5% (95% CI 32.4-36.6%). A logistic regression revealed that typical COVID-19 symptoms significantly declined over the course of the study and throughout the COVID-19 pandemic, and that among the vaccinated, significantly fewer presented with an infection exhibiting typical symptoms. The employed lasso regression model indicated that only higher viral load and typical COVID-19 symptoms significantly increase the likelihood of a positive RDT result in the case of a SARS-CoV-2 infection directly. ConclusionOur findings indicate that only viral load and COVID-19 symptoms directly influence RDT performance while the obtained effects of COVID-19 vaccination and Omicron VOC both reducing RDT performance were mediated by these two factors. RDTs remain an adequate diagnostic tool for detecting SARS-CoV-2 in individuals showing respiratory symptoms. RDTs show promise beyond SARS-CoV-2, proving adaptable for detecting other pathogens like Influenza and RSV, highlighting their ongoing importance in infection control and prevention efforts.
Subject(s)
COVID-19 , Severe Acute Respiratory SyndromeABSTRACT
The incidence has been widely used to assess the epidemiological situation during the COVID-19 pandemic and guide health policy. As testing requirements changed during the pandemic, more SARS-CoV-2 infections may have remained undetected. This study aims to evaluate the use of different indicators for estimating unreported SARS-CoV-2 infections. Monthly SARS-CoV-2 incidences in the general Bavarian population were compared with three indicators: incidence in healthcare workers (HCWs), incidence of patients, and incidence in visitors. Based on this, the number of unreported SARS-CoV-2 cases in the Bavarian population was estimated. The incidence from the visitors correlated moderately with the official incidences (r = 0.63). The general population incidence and the inpatient incidence are highly correlated (r = 0.91), as are the general population incidence and the HCWs incidence (r = 0.94). Between April 2020 and June 2023, the general population incidence was on average higher than the average incidence of the three indicators, after which the relationship reversed. The reversal of the relationship between the data series of the Bavarian population and the chosen indicators in June 2022 suggests that SARS-CoV-2 infections were underreported. Inpatient screening incidence and HCWs’ incidence in settings with low-threshold test accessibility are suitable indicators of current epidemiology in the general population.