scholarly journals Age and clinical signs as predictors of COVID-19 symptoms and cycle threshold value

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Ismail Dergaa ◽  
Muneer Abubaker ◽  
Amine Souissi ◽  
Abdul Rafi Mohammed ◽  
Amit Varma ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Threshold Value ◽  
Cycle Threshold

scholarly journals Association of Cartridge Based Nucleic Acid Amplification Test (CBNAAT) Grading on the Basis of Cycle Threshold Value with Conventional Microbiological Diagnosis in Pediatric Tuberculosis

2021 ◽  
Vol 7 (2) ◽  
pp. 72-77
Author(s):  
Bineeta Kashyap ◽  
Neha Gupta ◽  
Pooja Dewan ◽  
NP Singh ◽  
Ashwani Khanna
Keyword(s):  
Nucleic Acid ◽  
Positive Association ◽  
Threshold Value ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Microbiological Diagnosis ◽  
Significant Positive Association ◽  
Cycle Threshold ◽  
Culture Positivity ◽  
Pediatric Tuberculosis

Background: Microbiological confirmation of tuberculosis disease in children remains difficult due to paucibacillary disease and inability to obtain optimal samples. Recently introduced Cartridge based nucleic acid amplification test (CBNAAT) has improved microbiological diagnosis in pediatric tuberculosis. Objectives: We aimed to study association of CBNAAT grading based on cycle threshold value with conventional microbiological diagnosis. Methodology: This prospective study was conducted over a period from November 2016 to October 2017 in the Departments of Microbiology and Pediatrics, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi. CBNAAT positive pediatric TB cases ≤12 years were recruited and subjected to Ziehl-Neelsen staining for acid fast bacilli (AFB) & culture on Lowenstein Jensen medium. CBNAAT positivity was graded based on cycle threshold value: very low, low, medium and high. Results: Smear and culture positivity was highest (100%) among specimens with high positive CBNAAT result based on CT value. Time to culture positivity was inversely related to CBNAAT grading (p=0.000). Conclusion: CBNAAT grading has significant positive association with smear and culture positivity. Bangladesh Journal of Infectious Diseases 2020;7(2):72-77

scholarly journals A Real-World Comparison of SARS-CoV-2 Rapid Antigen vs. Polymerase Chain Reaction Testing in Florida

2021 ◽  
Author(s):  
Lao-Tzu Allan-Blitz ◽  
Jeffrey D. Klausner
Keyword(s):  
Polymerase Chain Reaction ◽  
Real World ◽  
Threshold Value ◽  
Test Results ◽  
Chain Reaction ◽  
Cycle Threshold ◽  
Large Populations ◽  
Symptom Status ◽  
Polymerase Chain ◽  
Antigen Tests

Background The reported sensitivity of rapid, antigen-based diagnostics for SARS-CoV-2 infection varies. Few studies have evaluated rapid antigen tests in real-world settings or among large populations. Methods Beginning October 2020, Florida offered individuals presenting for SARS-CoV-2 testing polymerase chain reaction (PCR) testing if they tested positive by the Abbott BinaxNOW TM COVID-19 Ag Card, were symptomatic, or required or requested PCR testing. We compared test results among individuals who received both types of tests at four publicly-accessible testing sites across Florida. We calculated the positive percent agreement (PPA) between the two test types by symptom status. Subsequently, we evaluated the PPA among individuals regardless of symptoms with lower cycle threshold values (<30). Results Overall, 18,457 individuals were tested via both methods, of which 3,153 (17.1%) were positive by PCR. The PPA for the Abbott BinaxNOW TM COVID-19 Ag Card using the PCR comparator was 49.2% (95% CI 47.4%-50.9%). That performance was moderately improved among symptomatic individuals (51.9%; 95% CI 49.7%-54.0%). When restricted to positive PCR tests with a cycle threshold value <30, regardless of symptom status, the PPA was 75.3% (95% CI 72.8%-77.6%). Conclusion The PPA of the Abbott BinaxNOW TM COVID-19 Ag Card with PCR was lower than among previous reports. Our findings may reflect the performance of the BinaxNOW TM antigen test in real-world settings.

A CYCLE THRESHOLD VALUE-BASED EPIDEMIC PROGNOSTICATION TO MONITOR LONG-TERM EPIDEMIOLOGIC TRENDS OF SARS-COV-2 VIRUS

2021 ◽  
pp. 24-30
Author(s):  
Aditi Munmun Sengupta ◽  
Diptendu Chatterjee ◽  
Bibhuti Saha
Keyword(s):  
Meta Analysis ◽  
Threshold Value ◽  
High Viral Load ◽  
World Health ◽  
Rt Pcr ◽  
Cycle Threshold ◽  
Ct Value ◽  
Health Organization ◽  
The Impact

The real-time reverse transcription-polymerase chain reaction (RT-PCR) is considered as the sensitive proof for detecting the viral infection of the SARS-CoV-2 virus obtained from respiratory samples. The quantitative values for the analysis are benecial for estimating the transmissibility of people who test positive for SARS-CoV-2. This can be further achieved by analyzing the samples by semiquantitative means through the interpretation of the cycle threshold (Ct) values of RT-PCR that represent the rst cycle of PCR at which a detectable signal appears during the assays. The Ct value shows a correlation between high viral load and disease infectiousness, which is observed with other respiratory viruses, including the inuenza B infection and rhinovirus infection. Hence, the present study aims to analyze the surveillance of COVID-19 to monitor longer-term epidemiologic trends and trends in deaths due to COVID-19. In order to achieve this aim, the present review was reported to the preferred reporting items for systematic reviews and meta-analysis statements (PRISMA) for analyzing the Ct value-based epidemic predictions and to monitor long-term epidemiologic trends of SARS-CoV-2 virus. Total 33 studies have been nalized for nding out the results of the study. The epidemiologic parameter and a representative of the surveillance data for reporting to the World Health Organization were fullled by analyzing the systematic review and metaanalysis of the selected study. Moreover, the evaluation of the impact of the pandemic on the health care system and society was achieved by analyzing the studies mentioned here.

scholarly journals Low Cycle Threshold Value in Xpert MTB/RIF Assay May Herald False Detection of Tuberculosis and Rifampicin Resistance: A Study of Two Cases

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Jean Claude S Ngabonziza ◽  
Tom Decroo ◽  
Rodrigue Maniliho ◽  
Yves M Habimana ◽  
Armand Van Deun ◽  
...  
Keyword(s):  
Threshold Value ◽  
Rifampicin Resistance ◽  
False Detection ◽  
Cycle Threshold ◽  
Resistant Tuberculosis

Abstract We report 2 cases for whom Xpert MTB/RIF falsely signaled rifampicin-resistant tuberculosis, based on unusually low cycle threshold and 3 of 5 probes missing. Other mycobacterial tests were negative. Further optimization of the Xpert MTB/RIF algorithm is warranted.

scholarly journals Diagnostic SARS-CoV-2 Cycle Threshold Value Predicts Disease Severity, Survival, and Six-Month Sequelae in COVID-19 Symptomatic Patients

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 281
Author(s):  
Mattia Trunfio ◽  
Francesco Venuti ◽  
Francesca Alladio ◽  
Bianca Maria Longo ◽  
Elisa Burdino ◽  
...  
Keyword(s):  
Disease Severity ◽  
Clinical Manifestations ◽  
Signs And Symptoms ◽  
Predictive Marker ◽  
Threshold Value ◽  
Nasopharyngeal Swab ◽  
Cycle Threshold ◽  
Composite Scale ◽  
Group B ◽  
Novel Coronavirus

To date, there is no severe acute respiratory syndrome coronavirus 2-(SARS-CoV-2)-specific prognostic biomarker available. We assessed whether SARS-CoV-2 cycle threshold (Ct) value at diagnosis could predict novel CoronaVirus Disease 2019 (COVID-19) severity, clinical manifestations, and six-month sequelae. Hospitalized and outpatient cases were randomly sampled from the diagnoses of March 2020 and data collected at 6 months by interview and from the regional database for COVID-19 emergency. Patients were stratified according to their RNA-dependent-RNA-polymerase Ct in the nasopharyngeal swab at diagnosis as follows: Group A ≤ 20.0, 20.0 < group B ≤ 28.0, and Group C > 28.0. Disease severity was classified according to a composite scale evaluating hospital admission, worst oxygen support required, and survival. Two hundred patients were included, 27.5% in Groups A and B both, 45.0% in Group C; 90% of patients were symptomatic and 63.7% were hospitalized. The median time from COVID-19 onset to swab collection was five days. Lethality, disease severity, type, and number of signs and symptoms, as well as six-month sequelae distributed inversely among the groups with respect to SARS-CoV-2 Ct. After controlling for confounding, SARS-CoV-2 Ct at diagnosis was still associated with COVID-19-related death (p = 0.023), disease severity (p = 0.023), number of signs and symptoms (p < 0.01), and presence of six-month sequelae (p < 0.01). Early quantification of SARS-CoV-2 may be a useful predictive marker to inform differential strategies of clinical management and resource allocation.

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