scholarly journals Analytical Validation and Clinical Application of Rapid Serological Tests for SARS-CoV-2 Suitable for Large-Scale Screening

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 869
Author(s):  
Amedeo De Nicolò ◽  
Valeria Avataneo ◽  
Jessica Cusato ◽  
Alice Palermiti ◽  
Jacopo Mula ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Real Time Pcr ◽  
Large Scale ◽  
High Sensitivity ◽  
Analytical Validation ◽  
Pcr Assay ◽  
Serological Tests ◽  
Flow Test ◽  
Lateral Flow Test ◽  
Large Scale Screening

Recently, large-scale screening for COVID-19 has presented a major challenge, limiting timely countermeasures. Therefore, the application of suitable rapid serological tests could provide useful information, however, little evidence regarding their robustness is currently available. In this work, we evaluated and compared the analytical performance of a rapid lateral-flow test (LFA) and a fast semiquantitative fluorescent immunoassay (FIA) for anti-nucleocapsid (anti-NC) antibodies, with the reverse transcriptase real-time PCR assay as the reference. In 222 patients, LFA showed poor sensitivity (55.9%) within two weeks from PCR, while later testing was more reliable (sensitivity of 85.7% and specificity of 93.1%). Moreover, in a subset of 100 patients, FIA showed high sensitivity (89.1%) and specificity (94.1%) after two weeks from PCR. The coupled application for the screening of 183 patients showed satisfactory concordance (K = 0.858). In conclusion, rapid serological tests were largely not useful for early diagnosis, but they showed good performance in later stages of infection. These could be useful for back-tracing and/or to identify potentially immune subjects.

Impedance Screening for Preschool Children: State of the Art

1979 ◽  
Vol 88 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Jack L. Paradise ◽  
Clyde G. Smith
Keyword(s):  
Preschool Children ◽  
Middle Ear ◽  
Large Scale ◽  
High Sensitivity ◽  
Cutoff Point ◽  
Screening Programs ◽  
Large Numbers ◽  
Middle Ear Disease ◽  
High Degree ◽  
Large Scale Screening

As a test for detecting middle ear disease among preschool children, tympanometry — as opposed to audiometry — has three advantageous attributes: a high degree of sensitivity, minimal need for subject cooperation, and total objectivity. For these reasons interest has arisen in tympanometry as a method for screening, i.e., identifying children with previously undetected middle ear disease. However, uncertainty persists concerning the importance of detecting apparently asymptomatic middle ear effusions, and concerning optimal methods, or even the advisability, of treating them. Further, the sensitivity and specificity of tympanometry depend on how the pass-fail cutoff point is defined. Defining this cutoff point so as to achieve high sensitivity may result in excessively low specificity, with the production of large numbers of false-positives who then become overreferrals. Data are presented to show how the validity of the test may be increased to some extent by attention to the gradient of “negative-pressure” tympanograms. At the present time, given the various aforementioned uncertainties, and with adequate validation as to the presence or absence of disease often lacking in reported studies of impedance screening in preschool populations, the cumulative results of these studies do not warrant embarking on large-scale screening programs. What is needed instead is additional research to explore the issue further.

Exploring a phage-based real-time PCR assay for diagnosing Acinetobacter baumannii bloodstream infections with high sensitivity

2018 ◽  
Vol 1044 ◽  
pp. 147-153 ◽  
Author(s):  
Jun Luo ◽  
Mengwei Jiang ◽  
Jin Xiong ◽  
Junhua Li ◽  
Xiaoxu Zhang ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Real Time ◽  
Real Time Pcr ◽  
Bloodstream Infections ◽  
High Sensitivity ◽  
Pcr Assay

scholarly journals The Light and Shadow of Rapid Serological Tests for SARS-CoV-2 Infection: Results from a Study in a Large Emergency Department

2020 ◽  
Vol 17 (18) ◽  
pp. 6493
Author(s):  
Daniela Loconsole ◽  
Francesca Centrone ◽  
Caterina Morcavallo ◽  
Silvia Campanella ◽  
Anna Sallustio ◽  
...  
Keyword(s):  
Emergency Department ◽  
Real Time ◽  
Real Time Pcr ◽  
Respiratory Symptoms ◽  
Large Scale ◽  
Serological Test ◽  
Serological Tests ◽  
Serological Assay ◽  
Infected People ◽  
Screening Programs

A critical point in the management of the SARS-CoV-2 pandemic is the need to promptly identify the greatest number of infected people and to implement strict public health measures. In this study, the performance of a rapid serological test in a clinical setting was evaluated. Samples from 819 consecutive patients (with or without respiratory symptoms) admitted to a large Emergency Department were tested between 23 March and 21 April 2020. Patient samples were tested in a real-time PCR assay and a serological assay. In total, 148/819 patients (18.1%) tested positive for SARS-CoV-2 by real-time PCR. The serological test revealed that 70/819 patients (8.5%) had anti-SARS-CoV-2 IgM and/or IgG. The prevalence of anti-SARS-CoV-2 antibodies was significantly higher in patients with respiratory symptoms lasting for >7 days than in those with respiratory symptoms lasting for 0–7 days (p < 0.001). The serological assay had an overall sensitivity of 35.1% and an overall specificity of 97.3%. A high negative predictive value (96.7%) was reported for patients without respiratory symptoms. The results confirm that rapid serological assays alone are not sufficient for diagnosis of SARS-CoV-2 infection but can be incorporated into large-scale screening programs during periods in which the virus circulation is low.

Development and validation of a quantitative real-time PCR assay for the early diagnosis of coccidioidomycosis

2014 ◽  
Vol 79 (2) ◽  
pp. 214-221 ◽  
Author(s):  
Sara Gago ◽  
María José Buitrago ◽  
Karl V. Clemons ◽  
Manuel Cuenca-Estrella ◽  
Laurence F. Mirels ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Real Time ◽  
Real Time Pcr ◽  
Quantitative Real Time Pcr ◽  
Pcr Assay ◽  
Development And Validation

scholarly journals Real-time evaluation of an optimized real-time PCR assay versus Brilliance chromogenic MRSA agar for the detection of meticillin-resistant Staphylococcus aureus from clinical specimens

2011 ◽  
Vol 60 (3) ◽  
pp. 323-328 ◽  
Author(s):  
J. Danial ◽  
M. Noel ◽  
K. E. Templeton ◽  
F. Cameron ◽  
F. Mathewson ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Test Performance ◽  
High Sensitivity ◽  
Turnaround Time ◽  
Homology Search ◽  
Pcr Assay ◽  
Indirect Measure ◽  
The Mean

A total of 1204 meticillin-resistant Staphylococcus aureus (MRSA) screens (3340 individual swabs) were tested to evaluate a staphylococcal cassette chromosome mec (SCCmec) real-time PCR. In total, 148 (12.3 %) of the screens were MRSA-positive, where 146 (12.1 %) were MRSA-positive by the SCCmec real-time PCR assay. In contrast, 128 (10.6 %) screens were MRSA-positive by culture. One hundred and twenty-six (10.5 %) of the screens were positive by both culture and PCR. Twenty of the 1204 screens (1.66 %) were negative by culture but positive by PCR; these samples were sequenced. In 14 of the cases, a homology search confirmed the sequence as SCCmec, indicating that these samples could be considered true positives. Two of the 1204 (0.2 %) screens were positive by culture and negative by PCR. The mean turnaround time (TAT) for PCR-negative swabs was 6 h 12 min and for PCR-positive swabs was 6 h 48 min. In comparison, for culture-negative swabs the mean TAT was 29 h 30 min and for culture-positive swabs was 69 h. The cost per swab for routine culture was £0.41 (€0.48) and that of the real-time PCR assay was £2.35 (€2.75). This optimized, in-house, inexpensive, real-time PCR test maintained a very high sensitivity and specificity when evaluated under real-time laboratory conditions. The TAT of this real-time PCR assay was substantially lower than that of chromogenic culture. It was also maintained throughout the entire process, which can be taken as an indirect measure of test performance. This study showed that implementation of a molecular test can be achieved with limited resources in a standard microbiology laboratory.

scholarly journals Use of Multiplex Real-Time PCR To Diagnose Scrub Typhus

2017 ◽  
Vol 55 (5) ◽  
pp. 1377-1387 ◽  
Author(s):  
Wiwit Tantibhedhyangkul ◽  
Ekkarat Wongsawat ◽  
Saowaluk Silpasakorn ◽  
Duangdao Waywa ◽  
Nuttawut Saenyasiri ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Real Time ◽  
Real Time Pcr ◽  
Scrub Typhus ◽  
Febrile Illness ◽  
Asia Pacific ◽  
Diagnostic Tools ◽  
Pcr Assay ◽  
Content Type ◽  
Serologic Tests

ABSTRACTScrub typhus, caused byOrientia tsutsugamushi, is a common cause of acute undifferentiated febrile illness in the Asia-Pacific region. However, its nonspecific clinical manifestation often prevents early diagnosis. We propose the use of PCR and serologic tests as diagnostic tools. Here, we developed a multiplex real-time PCR assay using hydrolysis (TaqMan) probes targetingO. tsutsugamushi47-kDa,groEL, and human interferon beta (IFN-β gene) genes to improve early diagnosis of scrub typhus. The amplification efficiency was higher than 94%, and the lower detection limit was 10 copies per reaction. We used a human gene as an internal DNA quality and quantity control. To determine the sensitivity of this PCR assay, we selected patients with confirmed scrub typhus who exhibited a clear 4-fold increase in the level of IgG and/or IgM. The PCR assay result was positive in 45 of 52 patients, indicating a sensitivity of 86.5% (95% confidence interval [CI]: 74.2 to 94.4). The PCR assessment was negative for all 136 non-scrub typhus patients, indicating a specificity of 100% (95% CI: 97.3 to 100). In addition, this test helped diagnose patients with inconclusive immunofluorescence assay (IFA) results and using single blood samples. In conclusion, the real-time PCR assay proposed here is sensitive and specific in diagnosing scrub typhus. Combining PCR and serologic tests will improve the diagnosis of scrub typhus among patients presenting with acute febrile illness.

scholarly journals Quantification of Leishmania infantum DNA by a Real-Time PCR Assay with High Sensitivity

2004 ◽  
Vol 42 (11) ◽  
pp. 5249-5255 ◽  
Author(s):  
C. Mary ◽  
F. Faraut ◽  
L. Lascombe ◽  
H. Dumon
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Leishmania Infantum ◽  
High Sensitivity ◽  
Pcr Assay

scholarly journals Efficacy of Monocyte Distribution Width in the Early Diagnosis of Sepsis: A Diagnostic Meta-Analysis

2021 ◽  
Author(s):  
Jiahao Chen ◽  
Qiang Guo
Keyword(s):  
Early Diagnosis ◽  
Large Scale ◽  
Meta Analysis ◽  
Delayed Diagnosis ◽  
Area Under The Curve ◽  
High Sensitivity ◽  
Inexpensive Method ◽  
Diagnostic Efficacy ◽  
Distribution Width ◽  
Non Invasive

Abstract Background: Delayed diagnosis of sepsis urgently requires a fast, convenient, and inexpensive method to improve the early diagnosis of sepsis. Increasing evidence showed that monocyte distribution width (MDW) could be used as a non-invasive biomarker with high sensitivity and specificity for the early diagnosis of sepsis. However, the accuracy and reliability of its diagnosis are still controversial in different studies. Method: A meta-analysis of all available studies regarding the association between MDW and the diagnosis of sepsis was performed to systematically evaluate the diagnostic efficacy of MDW in the prediction of sepsis. Results: The estimated results of all eight studies are as follows: sensitivity, 0.84 (95% CI 0.77, 0.90); specificity, 0.68 (95% CI 0.54, 0.80); PLR, 2.7 (95% CI 1.8, 4.1); NLR, 0.23 (95% CI 0.15, 0.35); DOR is 12 (95% CI 5, 25). The corresponding overall area under the curve is 0.85 (95% CI 0.82, 0.88). Conclusion: In conclusion, this meta-analysis demonstrates that MDW has high accuracy in distinguishing patients with sepsis from healthy controls for early diagnosis of sepsis. However, large-scale prospective studies and joint diagnosis with other indicators are urgently required to confirm our findings and their utilization for routine clinical diagnosis in the future.

scholarly journals Toward point-of-care diagnostics of Candida auris

2020 ◽  
Author(s):  
Geoffrey Mulberry ◽  
Sudha Chaturvedi ◽  
Vishnu Chaturvedi ◽  
Brian N. Kim
Keyword(s):  
New York ◽  
Real Time ◽  
Real Time Pcr ◽  
Positive Impact ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Clinical Samples ◽  
Pcr Assay ◽  
Candida Auris

AbstractCandida auris is a multidrug-resistant yeast that presents global health threat for the hospitalized patients. Early diagnostic of C. auris is crucial in control, prevention, and treatment. Candida auris is difficult to identify with standard laboratory methods and often can be misidentified leading to inappropriate management. A newly-devised real-time PCR assay played an important role in the ongoing investigation of the C. auris outbreak in New York metropolitan area. The assay can rapidly detect C. auris DNA in surveillance and clinical samples with high sensitivity and specificity, and also useful for confirmation of C. auris cultures. Despite its positive impact, the real-time PCR assay is difficult to deploy at frontline laboratories due to high-complexity set-up and operation. Using a low-cost handheld real-time PCR device, we show that the C. auris can potentially be identified in a low-complexity assay without the need for high-cost equipment. An implementation of low-cost real-time PCR device in hospitals and healthcare facilities is likely to accelerate the diagnosis of C. auris and for control of the global epidemic.

scholarly journals A Novel Real-Time PCR-Based Screening Test with Pooled Fecal Samples for Bovine Johne’s Disease

2020 ◽  
Vol 58 (12) ◽  
Author(s):  
Satoko Kawaji ◽  
Reiko Nagata ◽  
Yasutaka Minegishi ◽  
Yumi Saruyama ◽  
Akiko Mita ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Pcr Assay ◽  
Serological Tests ◽  
Fecal Samples ◽  
Content Type ◽  
Cattle Herds

ABSTRACT Johne’s disease (JD) is an economically important infectious disease in livestock farming caused by Mycobacterium avium subsp. paratuberculosis. As an alternative to serological tests, which are used mainly for the screening of whole herds, we developed a novel ResoLight-based real-time PCR (RL-PCR) assay with pooled fecal samples for the detection of fecal shedders in cattle herds. The RL-PCR assay included an internal amplification control (IC) which was amplified using the same primer pair as the target molecule M. avium subsp. paratuberculosis IS900 and differentiated based on melting temperatures. Individual fecal suspensions were pooled and concentrated by centrifugation to avoid a loss of sensitivity by the dilution effect. Combined with a DNA extraction kit (Johne-PureSpin; FASMAC), no inhibition of PCR amplification was observed with up to 15 fecal samples in a pool. The detection limit of RL-PCR at a pool size of 10 was 10 M. avium subsp. paratuberculosis organisms per gram of feces, which was comparable to that of individual testing. A total of 2,654 animals in 12 infected herds were screened by individual antibody-enzyme-linked immunosorbent assay (ELISA) and the RL-PCR assay using pooled feces. Fifty animals were diagnosed with JD through the screening by RL-PCR, compared with only 5 by ELISA (which were also positive in RL-PCR). In 7 JD-free herds, the results of 4 out of 327 pools (1.2%) were invalid due to the lack of IC amplification, and then animals were confirmed negative individually. Our results suggest that implementation of herd screening by pooled RL-PCR would advance the monitoring and control of JD in cattle herds.

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