SARS-CoV-2 viral load and shedding kinetics

Nature Reviews Microbiology, Journal Year: 2022, Volume and Issue: unknown

Published: Dec. 2, 2022

Language: Английский

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Performance of antigen lateral flow devices in the UK during the alpha, delta, and omicron waves of the SARS-CoV-2 pandemic: a diagnostic and observational study

The Lancet Infectious Diseases, Journal Year: 2023, Volume and Issue: 23(8), P. 922 - 932

Published: March 28, 2023

BackgroundAntigen lateral flow devices (LFDs) have been widely used to control SARS-CoV-2. We aimed improve understanding of LFD performance with changes in variant infections, vaccination, viral load, and use, the detection infectious individuals.MethodsIn this diagnostic study, paired RT-PCR test results were prospectively collected from asymptomatic symptomatic participants UK between Nov 4, 2020, March 21, 2022, support National Health Service (NHS) England's Test Trace programme. The LFDs evaluated Innova SARS-CoV-2 Antigen Rapid Qualitative Test, Orient Gene Covid-19 (Antigen) Self-Test, Acon Flowflex (Self-Testing). across various community testing settings, including predeployment sites, routine centres, homes, schools, universities, workplaces, targeted testing, health-care workers. multivariable logistic regression analyse sensitivity specificity using as a reference standard, adjusting for manufacturer, setting, age, sex, assistance, symptom status, vaccination variant. contact tracing data NHS (Jan 1, 2021, Jan 11, 2022) estimate proportion transmitting index patients (with ≥1 RT-PCR-positive or LFD-positive contact) potentially detectable by (specifically Innova, most LFD) time, accounting variant, status.FindingsWe assessed 75 382 pairs tests. Of these, 4131 (5·5%) RT-PCR-positive. versus was 63·2% (95% CI 61·7–64·6) 99·71% 99·66–99·74). Increased load independently associated being positive (adjusted odds ratio [aOR] 2·85 [95% 2·66–3·06] per 1 log10 copies mL increase; p<0·0001). There no evidence that differed delta (B.1.617.2) infections alpha (B.1.1.7) pre-alpha (B.1.177) (aOR 1·00 [0·69–1·45]; p=0·99), whereas omicron (BA.1 BA.2) appeared more likely be 1·63 [1·02–2·59]; p=0·042). Sensitivity higher (68·7% 66·9–70·4]) than (52·8% [50·1–55·4]). Among 347 374 unique probable onward transmission, 78·3% 75·3–81·2) estimated (Innova), mostly stable time successive variants. Overall, lower (57·6% [53·6–61·9]) (79·7% [76·7–82·5]).InterpretationLFDs remained able detect throughout vaccine roll-out different can transmit others reduce risk transmission. However, is individuals individuals.FundingUK Security Agency, Government Department Social Care, Institute Research (NIHR) Protection Unit Healthcare Associated Infections Antimicrobial Resistance, University Oxford NIHR Biomedical Centre.

Language: Английский

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Estimates of SARS-CoV-2 Omicron BA.2 Subvariant Severity in New England

JAMA Network Open, Journal Year: 2022, Volume and Issue: 5(10), P. e2238354 - e2238354

Published: Oct. 25, 2022

Importance The SARS-CoV-2 Omicron subvariant, BA.2, may be less severe than previous variants; however, confounding factors make interpreting the intrinsic severity challenging. Objective To compare adjusted risks of mortality, hospitalization, intensive care unit admission, and invasive ventilation between BA.2 subvariant Delta variants, after accounting for multiple confounders. Design, Setting, Participants This was a retrospective cohort study that applied an entropy balancing approach. Patients in multicenter inpatient outpatient system New England with COVID-19 March 3, 2020, June 20, 2022, were identified. Exposures Cases assigned as being exposed to (B.1.617.2) variant, (B.1.1.529) or lineage subvariants. Main Outcomes Measures primary outcome planned before analysis risk 30-day mortality. Secondary outcomes included ventilation, admissions. Results Of 102 315 confirmed cases (mean [SD] age, 44.2 [21.6] years; 63 482 women [62.0%]), 20 770 labeled 52 605 B.1.1.529 28 940 Patient excluded if they occurred outside prespecified temporal windows associated variants had minimal longitudinal data Mass General Brigham COVID-19. Mortality rates 0.7% (B.1.617.2), 0.4% (B.1.1.529), 0.3% (BA.2). odds ratio mortality from variant compared subvariants 2.07 (95% CI, 1.04-4.10) original 2.20 1.56-3.11). For all outcomes, significantly variants. Conclusions Relevance In this study, having accounted variety found intrinsically both With respect these profile appears diminishing taking into account various including therapeutics, vaccinations, prior infections.

Language: Английский

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Analytical Sensitivity of Eight Different SARS-CoV-2 Antigen-Detecting Rapid Tests for Omicron-BA.1 Variant

Microbiology Spectrum, Journal Year: 2022, Volume and Issue: 10(4)

Published: Aug. 8, 2022

Sensitivity for detecting Omicron-BA.1 shows high heterogenicity between Ag-RDTs, necessitating a careful consideration when using these tests to guide infection prevention measures. Analytical and retrospective testing is proxy timely solution generate rapid performance data, but it not replacement clinical evaluations, which are urgently needed. Biological technical reasons detection failure by some Ag-RDTs need be further investigated.

Language: Английский

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Diagnostic accuracy of covid-19 rapid antigen tests with unsupervised self-sampling in people with symptoms in the omicron period: cross sectional study

BMJ, Journal Year: 2022, Volume and Issue: unknown, P. e071215 - e071215

Published: Sept. 14, 2022

To assess the performance of rapid antigen tests with unsupervised nasal and combined oropharyngeal self-sampling during omicron period.Prospective cross sectional diagnostic test accuracy study.Three public health service covid-19 sites in Netherlands, 21 December 2021 to 10 February 2022.6497 people symptoms aged ≥16 years presenting for testing.Participants had a swab sample taken reverse transcription polymerase chain reaction (RT-PCR, reference test) received one perform using either (during emergence omicron, when accounted >90% infections, phase 1) or subsequent (phase 2; >99% infections). The evaluated were Flowflex (Acon Laboratories; 1 only), MPBio (MP Biomedicals), Clinitest (Siemens-Healthineers).The main outcomes sensitivity, specificity, positive negative predictive values each self-test, RT-PCR testing as standard.During 1, 45.0% (n=279) participants group, 29.1% (n=239) 35.4% ((n=257) group confirmatory testers (previously tested by self-test at own initiative). Overall sensitivities 79.0% (95% confidence interval 74.7% 82.8%) Flowflex, 69.9% (65.1% 74.4%) MPBio, 70.2% (65.6% 74.5%) Clinitest. Sensitivities substantially higher (93.6%, 83.6%, 85.7%, respectively) than those who other reasons (52.4%, 51.5%, 49.5%, respectively). decreased from 87.0% 80.9% (P=0.16 χ2 test), 80.0% 73.0% (P=0.60), 83.1% 70.3% (P=0.03), respectively, transitioning accounting 29% infections >95% infections. During 2, 53.0% (n=288) 44.4% (n=290) testers. 83.0% (78.8% 86.7%) 77.3% (72.9% 81.2%) When was compared self-sampling, found be slightly (87.4% 86.1%, (69.3% 59.9%, respectively).Sensitivities three but only statistically significant appeared influenced proportion improved after addition self-sampling. A result justifies prompt self-isolation without need testing. Individuals should adhere general preventive measures because false cannot ruled out. Manufacturers may consider extending their instructions use include manufacturers evaluating this well.

Language: Английский

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The Infectious Diseases Society of America Guidelines on the Diagnosis of COVID-19: Antigen Testing

Clinical Infectious Diseases, Journal Year: 2023, Volume and Issue: 78(7), P. e350 - e384

Published: Jan. 23, 2023

Immunoassays designed to detect SARS-CoV-2 protein antigens (Ag) are commonly used diagnose COVID-19. The most widely tests lateral flow assays that generate results in approximately 15 minutes for diagnosis at the point-of-care. Higher throughput, laboratory-based Ag have also been developed. number of commercially available detection has increased rapidly, as COVID-19 diagnostic literature. Infectious Diseases Society America (IDSA) convened an expert panel perform a systematic review literature and develop best-practice guidance related testing. This guideline is update third series frequently updated guidelines developed by IDSA. IDSA's goal was evidence-based recommendations or suggestions assist clinicians, clinical laboratories, patients, public health authorities, administrators, policymakers decisions optimal use both medical nonmedical settings. A multidisciplinary infectious diseases microbiologists, experts identified prioritized questions tests. relevant, peer-reviewed published conducted through 1 April 2022. Grading Recommendations Assessment, Development, Evaluation (GRADE) methodology assess certainty evidence make testing recommendations. made 10 address symptomatic asymptomatic individuals single versus repeat strategies. US Food Drug Administration (FDA) with Emergency Use Authorization (EUA) high specificity low moderate sensitivity compared nucleic acid amplification (NAAT). test dependent on presence absence symptoms and, timing after symptom onset. In cases, positive can be acted upon without confirmation. Results point-of-care comparable those testing, observed unobserved self-collection specimens yields similar results. Modeling suggests increases once, but no empirical data were inform this question. Based these observations, rapid RT-PCR NAAT remain methods choice diagnosing infection. However, when timely molecular not readily logistically infeasible, helps identify Data insufficient recommendation about utility guide release patients from isolation. overall quality supporting graded very moderate.

Language: Английский

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Clinical performance of rapid antigen tests in comparison to RT‐PCR for SARS‐COV‐2 diagnosis in Omicron variant: A systematic review and meta‐analysis

Reviews in Medical Virology, Journal Year: 2023, Volume and Issue: 33(2)

Published: Feb. 15, 2023

Abstract The Omicron variant of concern has a high level mutations in different genes that raised awareness about the performance immunological products such as vaccines and antigen detection kits. In this systematic review meta‐analysis, we investigated whether had significant influence on rapid test (RAT) comparison to PCR. We registered meta‐analysis PROSPERO with registration number CRD42022355510. searched PubMed, Scopus, Embase, Web Science databases systematically 1 August 2022. After article screening, assessed quality included studies based JBI checklist. Following data extraction, performed using R software. 18 qualified articles presenting sufficient RATs RT‐PCR infections. pooled specificity sensitivity were 1.000 (0.997–1.000) 0.671 (0.595–0.721), respectively. FDA‐approved kits showed better than WHO‐approved ones 0.728 (0.620–0.815). use nasal swabs higher compared nasopharyngeal swabs. for samples CT‐value >25 was 0.108 (0.048–0.227). Rapid tests show impaired COVID‐19 diagnosis when is circulating, particularly low viral loads.

Language: Английский

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Portable Breath-Based Volatile Organic Compound Monitoring for the Detection of COVID-19 During the Circulation of the SARS-CoV-2 Delta Variant and the Transition to the SARS-CoV-2 Omicron Variant

JAMA Network Open, Journal Year: 2023, Volume and Issue: 6(2), P. e230982 - e230982

Published: Feb. 28, 2023

Importance Breath analysis has been explored as a noninvasive means to detect COVID-19. However, the impact of emerging variants SARS-CoV-2, such Omicron, on exhaled breath profile and diagnostic accuracy is unknown. Objective To evaluate accuracies detecting patients with COVID-19 when SARS-CoV-2 Delta Omicron were most prevalent. Design, Setting, Participants This study included cohort who had positive negative test results for using reverse transcriptase polymerase chain reaction between April 2021 May 2022, which covers period variant was overtaken by major variant. Patients enrolled through intensive care units emergency department at University Michigan Health System. Patient analyzed portable gas chromatography. Main Outcomes Measures Different sets VOC biomarkers identified that distinguished (SARS-CoV-2 variants) non–COVID-19 illness. Results Overall, 205 samples from 167 adult analyzed. A total 77 (mean [SD] age, 58.5 [16.1] years; 41 [53.2%] male patients; 13 [16.9%] Black 59 [76.6%] White patients) COVID-19, 91 54.3 [17.1] 43 [47.3%] 11 [12.1%] 76 [83.5%] Several over multiple days. Among 94 samples, in infected or other variants, 53 2022 variant, based State US Centers Disease Control Prevention surveillance data. Four found distinguish (Delta illness an 94.7%. dropped substantially 82.1% these applied new (accuracy, 90.9%). earlier 91.5% (all vs 90.2% accuracy. Conclusions Relevance The findings this suggest promise detection. similar rapid antigen testing, emergence poses challenges. warrant additional evaluation how overcome challenges use improve diagnosis patients.

Language: Английский

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SARS-CoV-2 rapid antigen test sensitivity and viral load in newly symptomatic hospital employees in Berlin, Germany, December, 2020 to February, 2022: an observational study

The Lancet Microbe, Journal Year: 2024, Volume and Issue: 5(6), P. e538 - e546

Published: May 14, 2024

Evolving SARS-CoV-2 variants and changing levels of pre-existing immunity require re-evaluation antigen-detecting rapid diagnostic test (Ag-RDT) performance. We investigated possible associations between Ag-RDT sensitivity various potential influencing factors, such as immunisation status viral variant, in symptomatic hospital employees.

Language: Английский

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Virus variant–specific clinical performance of SARS coronavirus two rapid antigen tests in point-of-care use, from November 2020 to January 2022

Clinical Microbiology and Infection, Journal Year: 2022, Volume and Issue: 29(2), P. 225 - 232

Published: Aug. 24, 2022

Language: Английский

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