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1.
SSRN; 2022.
Preprint in English | SSRN | ID: ppcovidwho-332348

ABSTRACT

Background: Access to RT-PCR testing, the gold standard for SARS-CoV-2 detection, is limited throughout the world, due to restricted resources, available infrastructure, and high costs. Antigen-detecting, rapid diagnostic tests (Ag-RDTs) overcome some of these barriers, but independent clinical validations in settings of intended use are scarce. To inform the World Health Organisation’s (WHO) emergency use listing (EUL) procedure and ensure affordable, high-quality Ag-RDTs, we assessed the performance and ease-of-use of the SureStatus for SARS-CoV-2. Methods: This prospective, multi-center diagnostic accuracy study recruited unvaccinated participants with presumed SARS-CoV-2 infection in India and Germany from Dec 2019 to Mar 2021 when predominantly alpha (B.1.1.7) variant was circulating. Paired swabs were performed for (i) routine clinical RT-PCR testing (sampling was either nasopharyngeal (NP), or NP/OP combined) and (ii) for Ag-RDT (sampling was nasopharyngeal (NP)). Performance of the Ag-RDT was compared to RT-PCR overall, and according to predefined subgroups e.g., cycle threshold (Ct)-value, symptoms, and days from symptom onset. To understand usability, a System Usability Scale (SUS) questionnaire and ease-of-use (EoU) assessment were performed. Findings: A total of 1119 participants were included in the analysis of whom 205 (18·3%) were RT-PCR positive. SureStatus detected 169 out of 205 RT-PCR positive participants, reporting a sensitivity of 82·4% (95% CI: 76·6%-87·1%) and a specificity of 98·5% (95% CI: 97·4%-99·1%). In the first 7 days post symptom onset sensitivity was 90·7% (95% CI: 83·5%-94·9%). The test was characterized as easy to use (SUS: 85/100) and considered suitable for point-of-care settings although quality concerns were raised due to visibly contaminated packaging of swabs included in the test kits. Interpretation: The SureStatus diagnostic test can be considered a reliable test in the first week of SARS-CoV-2 infection with high sensitivity in combination with excellent usability.

2.
EBioMedicine ; 75: 103774, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1587927

ABSTRACT

BACKGROUND: Antigen-detecting rapid diagnostic tests (Ag-RDTs) for SARS-CoV-2 are important diagnostic tools. We assessed clinical performance and ease-of-use of seven Ag-RDTs in a prospective, manufacturer-independent, multi-centre cross-sectional diagnostic accuracy study to inform global decision makers. METHODS: Unvaccinated participants suspected of a first SARS-CoV-2 infection were recruited at six sites (Germany, Brazil). Ag-RDTs were evaluated sequentially, with collection of paired swabs for routine reverse transcription polymerase chain reaction (RT-PCR) testing and Ag-RDT testing. Performance was compared to RT-PCR overall and in sub-group analyses (viral load, symptoms, symptoms duration). To understandusability a System Usability Scale (SUS) questionnaire and ease-of-use (EoU) assessment were performed. FINDINGS: 7471 participants were included in the analysis. Sensitivities across Ag-RDTs ranged from 70·4%-90·1%, specificities were above 97·2% for all Ag-RDTs but one (93·1%).Ag-RDTs, Mologic, Bionote, Standard Q, showed diagnostic accuracy in line with WHO targets (> 80% sensitivity, > 97% specificity). All tests showed high sensitivity in the first three days after symptom onset (≥87·1%) and in individuals with viral loads≥ 6 log10SARS-CoV2 RNA copies/mL (≥ 88·7%). Usability varied, with Rapigen, Bionote and Standard Q reaching very good scores; 90, 88 and 84/100, respectively. INTERPRETATION: Variability in test performance is partially explained by variable viral loads in population evaluated over the course of the pandemic. All Ag-RDTs reach high sensitivity early in the disease and in individuals with high viral loads, supporting their role in identifying transmission relevant infections. For easy-to-use tests, performance shown will likely be maintained in routine implementation. FUNDING: Ministry of Science, Research and Arts, State of Baden-Wuerttemberg, Germany, internal funds from Heidelberg University Hospital, University Hospital Charité - Universitätsmedizin Berlin, UK Department of International Development, WHO, Unitaid.


Subject(s)
Antigens, Viral/immunology , COVID-19 Serological Testing , COVID-19 , Point-of-Care Systems , SARS-CoV-2/immunology , Adult , COVID-19/diagnosis , COVID-19/immunology , Female , Humans , Male , Middle Aged , Sensitivity and Specificity
3.
PLoS One ; 16(5): e0247918, 2021.
Article in English | MEDLINE | ID: covidwho-1388903

ABSTRACT

OBJECTIVES: Diagnostics are essential for controlling the pandemic. Identifying a reliable and fast diagnostic device is needed for effective testing. We assessed performance and ease-of-use of the Abbott PanBio antigen-detecting rapid diagnostic test (Ag-RDT). METHODS: This prospective, multi-centre diagnostic accuracy study enrolled at two sites in Germany. Following routine testing with reverse-transcriptase polymerase chain reaction (RT-PCR), a second study-exclusive swab was performed for Ag-RDT testing. Routine swabs were nasopharyngeal (NP) or combined NP/oropharyngeal (OP) whereas the study-exclusive swabs were NP. To evaluate performance, sensitivity and specificity were assessed overall and in predefined sub-analyses accordingly to cycle-threshold values, days after symptom onset, disease severity and study site. Additionally, an ease-of-use assessment (EoU) and System Usability Scale (SUS) were performed. RESULTS: 1108 participants were enrolled between Sept 28 and Oct 30, 2020. Of these, 106 (9.6%) were PCR-positive. The Abbott PanBio detected 92/106 PCR-positive participants with a sensitivity of 86.8% (95% CI: 79.0% - 92.0%) and a specificity of 99.9% (95% CI: 99.4%-100%). The sub-analyses indicated that sensitivity was 95.8% in Ct-values <25 and within the first seven days from symptom onset. The test was characterized as easy to use (SUS: 86/100) and considered suitable for point-of-care settings. CONCLUSION: The Abbott PanBio Ag-RDT performs well for SARS-CoV-2 testing in this large manufacturer independent study, confirming its WHO recommendation for Emergency Use in settings with limited resources.


Subject(s)
COVID-19 Serological Testing , COVID-19 , Point-of-Care Testing , SARS-CoV-2/immunology , Adult , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/immunology , Female , Germany/epidemiology , Humans , Male , Middle Aged , Sensitivity and Specificity , World Health Organization
4.
Infection ; 50(2): 395-406, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1353740

ABSTRACT

PURPOSE: Rapid antigen-detecting tests (Ag-RDTs) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can transform pandemic control. Thus far, sensitivity (≤ 85%) of lateral-flow assays has limited scale-up. Conceivably, microfluidic immunofluorescence Ag-RDTs could increase sensitivity for SARS-CoV-2 detection. METHODS: This multi-centre diagnostic accuracy study investigated performance of the microfluidic immunofluorescence LumiraDx™ assay, enrolling symptomatic and asymptomatic participants with suspected SARS-CoV-2 infection. Participants collected a supervised nasal mid-turbinate (NMT) self-swab for Ag-RDT testing, in addition to a professionally collected nasopharyngeal (NP) swab for routine testing with reverse transcriptase polymerase chain reaction (RT-PCR). Results were compared to calculate sensitivity and specificity. Sub-analyses investigated the results by viral load, symptom presence and duration. An analytical study assessed exclusivity and limit-of-detection (LOD). In addition, we evaluated ease-of-use. RESULTS: The study was conducted between November 2nd 2020 and 4th of December 2020. 761 participants were enrolled, with 486 participants reporting symptoms on testing day. 120 out of 146 RT-PCR positive cases were detected positive by LumiraDx™, resulting in a sensitivity of 82.2% (95% CI 75.2-87.5%). Specificity was 99.3% (CI 98.3-99.7%). Sensitivity was increased in individuals with viral load ≥ 7 log10 SARS-CoV2 RNA copies/ml (93.8%; CI 86.2-97.3%). Testing against common respiratory commensals and pathogens showed no cross-reactivity and LOD was estimated to be 2-56 PFU/mL. The ease-of-use-assessment was favourable for lower throughput settings. CONCLUSION: The LumiraDx™ assay showed excellent analytical sensitivity, exclusivity and clinical specificity with good clinical sensitivity using supervised NMT self-sampling. TRIAL REGISTRATION NUMBER AND REGISTRATION DATE: DRKS00021220 and 01.04.2020.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , Humans , Pandemics , Point-of-Care Systems , RNA, Viral , Sensitivity and Specificity
5.
PLoS One ; 16(7): e0255513, 2021.
Article in English | MEDLINE | ID: covidwho-1334778

ABSTRACT

BACKGROUND: Most data on COVID-19 was collected in hospitalized cases. Much less is known about the spectrum of disease in entire populations. In this study, we examine a representative cohort of primarily symptomatic cases in an administrative district in Southern Germany. METHODS: We contacted all confirmed SARS-CoV-2 cases in the administrative district. Consenting participants answered a retrospective survey either via a telephone, electronically or via mail. Clinical and sociodemographic features were compared between hospitalized and non-hospitalized patients. Additionally, we assessed potential risk factors for hospitalization and time to hospitalization in a series of regression models. RESULTS: We included 897 participants in our study, 69% out of 1,305 total cases in the district with a mean age of 47 years (range 2-97), 51% of which were female and 47% had a pre-existing illness. The percentage of asymptomatic, mild, moderate (leading to hospital admission) and critical illness (requiring mechanical ventilation) was 54 patients (6%), 713 (79%), 97 (11%) and 16 (2%), respectively. Seventeen patients (2%) died. The most prevalent symptoms were fatigue (65%), cough (62%) and dysgeusia (60%). The risk factors for hospitalization included older age (OR 1.05 per year increase; 95% CI 1.04-1.07) preexisting lung conditions (OR 3.09; 95% CI 1.62-5.88). Female sex was a protective factor (OR 0.51; 95% CI 0.33-0.77). CONCLUSION: This representative analysis of primarily symptomatic COVID-19 cases confirms age, male sex and preexisting lung conditions but not cardiovascular disease as risk factors for severe illness. Almost 80% of infection take a mild course, whereas 13% of patients suffer moderate to severe illness. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00022926. URL: https://www.drks.de/drks_web/setLocale_EN.do.


Subject(s)
COVID-19 , Hospitalization , SARS-CoV-2 , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , COVID-19/mortality , COVID-19/pathology , COVID-19/therapy , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors , Severity of Illness Index , Sex Factors
6.
F1000Res ; 9: 232, 2020.
Article in English | MEDLINE | ID: covidwho-769909

ABSTRACT

Since the first identified case of COVID-19 in Wuhan, China, the disease has developed into a pandemic, imposing a major challenge for health authorities and hospitals worldwide. Mathematical transmission models can help hospitals to anticipate and prepare for an upcoming wave of patients by forecasting the time and severity of infections. Taking the city of Heidelberg as an example, we predict the ongoing spread of the disease for the next months including hospital and ventilator capacity and consider the possible impact of currently imposed countermeasures.


Subject(s)
Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Models, Theoretical , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Betacoronavirus , COVID-19 , Cities/epidemiology , Germany/epidemiology , Humans , Pandemics , SARS-CoV-2
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