Assay for Screening of Blood Donors for Hepatitis B Surface Antigen Seropositivity

Comparative Evaluation of Fast Check and Enzyme Linked Immunosorbent Assay for Screening of Blood Donors for Hepatitis B Floor Antigen Seropositivity

 

Background: The Hepatitis B floor Antigen (HBsAg) is essentially the most utilized indicator marker of hepatitis B an infection. This examine assesses the accuracy of the 2 commonest screening assays used to detect HBsAg amongst blood donors.

Supplies and strategies: A complete of 350 eligible blood donors had been screened for HBsAg utilizing each Bio-Examine HBsAg Fast screening equipment (BioCheck Inc, South San Francisco, USA) and a fourth-generation Enzyme-Linked Immunoassays (ELISA) equipment, MonolisaTM HBs Ag Extremely (Bio-Rad Laboratories, Marnes-la-Coquette-France). Questionnaires had been used to inquire about danger elements for HBV an infection amongst blood donors. The calculation of sensitivity, specificity, unfavorable predictive and optimistic predictive values had been carried out by evaluating the efficiency of the speedy equipment with ELISA check because the reference normal.

Outcomes: The prevalence of HBV an infection utilizing Fast Diagnostic Check (RDT) was 5.7% however was 14.6% by ELISA. Utilizing ELISA as a reference, the sensitivity and specificity of RDT had been 31.4% and 98.7% respectively. The optimistic predictive worth and unfavorable predictive worth for RDT had been 80.0% and 89.4% respectively. General non-compliance with transfusion-transmitted an infection (TTI) risk-related deferral standards was 38%.

Conclusion: The low sensitivity of RDT kits precludes its steady use in excessive HBV endemic areas the place many donors fail to reveal full and truthful details about their danger for TTI. It’s urged that blood banks ought to complement the usage of RDT with a extra delicate assay equivalent to ELISA.

immunocon2019
immunocon2019

Head-to-Head Comparability of Fast and Automated Antigen Detection Exams for the Prognosis of SARS-CoV-2 An infection

 

(1) Background: The detection of SARS-CoV-2 RNA in nasopharyngeal samples by means of real-time reverse transcription-polymerase chain response (RT-PCR) is taken into account the usual gold technique for the prognosis of SARS-CoV-2 an infection. Antigen detection (AD) assessments are extra speedy, much less laborious, and cheaper options however nonetheless require scientific validation.

(2) Strategies: This examine in contrast the scientific efficiency of 5 AD assessments, together with 4 speedy AD (RAD) assessments (biotical, Panbio, Healgen, and Roche) and one automated AD check (VITROS). For that function, 118 (62.8%) symptomatic sufferers and 70 (37.2%) asymptomatic topics had been examined, and outcomes had been in comparison with RT-PCR.

(3) Outcomes: The efficiency of the RAD assessments was modest and allowed us to determine RT-PCR optimistic sufferers with increased viral masses. For Ct values ≤25, the sensitivity ranged from 93.1% (95% CI: 83.3-98.1%) to 96.6% (95% CI: 88.1-99.6%), which means that some samples with excessive viral masses had been missed. Contemplating the Ct worth proposed by the CDC for contagiousness (i.e., Ct values ≤33) sensitivities ranged from 76.2% (95% CI: 65.4-85.1%) to 88.8% (95% CI: 79.7-94.7%) whereas the specificity ranged from 96.3% (95% CI: 90.8-99.0%) to 99.1% (95% CI: 95.0-100%). The VITROS automated assay confirmed a 100% (95% CI: 95.5-100%) sensitivity for Ct values ≤33, and had a specificity of 100% (95% CI: 96.6-100%);

(4) Conclusions: In comparison with RAD assessments, the VITROS assay absolutely aligned with RT-PCR for Ct values as much as 33, which could enable a quicker, simpler and cheaper identification of SARS-CoV-2 contagious sufferers.

 

Analysis of two speedy antigen assessments to detect SARS-CoV-2 in a hospital setting

 

Profitable containment methods for the SARS-CoV-2 pandemic will depend upon dependable diagnostic assays. Level-of-care antigen assessments (POCT) might present an alternative choice to time-consuming PCR assessments to quickly display for acute infections on web site. Right here, we evaluated two SARS-CoV-2 antigen assessments: the STANDARD™ F COVID-19 Ag FIA (FIA) and the SARS-CoV-2 Fast Antigen Check (RAT). For diagnostic evaluation, we used a big set of PCR-positive and PCR-negative respiratory swabs from asymptomatic and symptomatic sufferers and well being care staff within the setting of two College Hospitals in Munich, Germany, i.e. emergency rooms, affected person care models or worker check facilities.

For FIA, general scientific sensitivity and specificity had been 45.4% (n = 381) and 97.8% (n = 360), respectively, and for RAT, 50.3% (n = 445) and 97.7% (n = 386), respectively. For major prognosis of asymptomatic and symptomatic people, diagnostic sensitivities had been 60.9% (FIA) (n = 189) and 64.5% (RAT) (n = 256). This questions these assessments’ utility for the dependable detection of acute SARS-CoV-2-infected people, particularly in high-risk settings. We help the proposal that convincing high-quality end result knowledge on the affect of false-negative and false-positive antigen check outcomes have to be obtained in a POCT setting. Furthermore, the efficacy of different testing methods to enhance PCR assays have to be evaluated by unbiased laboratories, previous to widespread implementation in nationwide and worldwide check methods.

 

An Aggregation-Induced Emission Materials Labeling Antigen-Primarily based Lateral Circulation Immunoassay Strip for Fast Detection of Escherichia coli O157:H7

 

Escherichia coli O157:H7 (E. coli O157:H7) is a harmful foodborne pathogen, primarily present in beef, milk, fruits, and their merchandise, inflicting hurt to human well being and even loss of life. Subsequently, the detection of E. coli O157:H7 in meals is especially essential. On this paper, we report a lateral move immunoassay strip (LFIS) primarily based on aggregation-induced emission (AIE) materials labeling antigen as a fluorescent probe for the speedy detection of E. coli O157:H7. The detection sensitivity of the strip is 105 CFU/mL, which is 10 instances increased than that of the colloidal gold check strip. This technique has good specificity and stability and can be utilized to detect about 250 CFU of E. coli O157:H7 efficiently in 25 g or 25 mL of beef, jelly, and milk. AIE-LFIS may be worthwhile in monitoring meals pathogens for speedy detection

 

Analysis of a speedy antigen check (Panbio™ COVID-19 Ag speedy check gadget) for SARS-CoV-2 detection in asymptomatic shut contacts of COVID-19 sufferers

 

Goals: There may be restricted info on the efficiency of speedy antigen detection (RAD) assessments to determine SARS-CoV-2-infected asymptomatic people. On this area examine, we evaluated the Panbio™ COVID-19 Ag Fast Check Machine (Abbott Diagnostics, Jena, Germany) for this function.

Strategies: A complete of 634 people (355 feminine; median age, 37 years; vary, 9-87) had been enrolled. Two nasopharyngeal swabs had been collected from family (n=338) and non-household contacts (n=296) of COVID-19 instances. RAD testing was carried out on the level of care. The RT-PCR check used was the TaqPath COVID-19 Combo Package (Thermo Fisher Scientific, Massachusetts, USA).

Outcomes: Family contacts had been examined at a median of two days (vary, 1-7) after prognosis of the index case, whereas non-household contacts (n=296) had been examined at a median of 6 days (vary, 1-7) after publicity. In whole, 79 people (12.4%) examined optimistic by RT-PCR, of whom 38 (48.1%) yielded optimistic RAD outcomes. The general sensitivity and specificity of the RAD check was 48.1% (95% CI: 37.4-58.9) and 100% (95% CI: 99.3-100), respectively. Sensitivity was increased in family (50.8%; 95% CI: 38.9-62.5) than in non-household (35.7%; 95% CI:16.3-61.2%) contacts. People testing optimistic by RAD check had been extra probably (P<0.001) to turn into symptomatic than their unfavorable counterparts.

Conclusion: The Panbio check shows low sensitivity in asymptomatic shut contacts of COVID-19 sufferers, significantly in non-household contacts. Nonetheless, establishing the optimum timing for higher respiratory tract assortment on this group appears crucial to pinpoint check sensitivity.

 

Efficiency traits of a speedy SARS-CoV-2 antigen detection assay at a public plaza testing web site in San Francisco

We evaluated the efficiency of the Abbott BinaxNOW TM Covid-19 speedy antigen check (Binax-CoV2) to detect virus amongst individuals, no matter signs, at a public plaza web site of ongoing group transmission. Titration with cultured SARS-CoV-2 yielded a human observable threshold between 1.6×10 4-4.3×10 Four viral RNA copies (cycle threshold (Ct) of 30.3-28.8).

Amongst 878 topics examined, 3% (26/878) had been optimistic by RT-PCR, of which 15/26 had Ct<30, indicating excessive viral load. 40% (6/15) of Ct<30 had been asymptomatic. Utilizing this Ct<30 threshold for Binax-CoV2 analysis, the sensitivity of Binax-CoV2 was 93.3% (14/15), 95% CI: 68.1-99.8%, and the specificity was 99.9% (855/856), 95% CI: 99.4-99.9%.

 

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