scholarly journals Differential Performance of CoronaCHEK SARS-CoV-2 Lateral Flow Antibody Assay by Geographic Origin of Samples

2021 ◽  
Author(s):  
Owen R Baker ◽  
M. Kate Grabowski ◽  
Ronald M Galiwango ◽  
Aminah Nalumansi ◽  
Jennifer Serwanga ◽  
...  
Keyword(s):  
False Positive ◽  
Geographic Origin ◽  
Febrile Illness ◽  
Lateral Flow ◽  
Serum Samples ◽  
False Positive Test ◽  
Assay Performance ◽  
History Of ◽  
The Impact ◽  
Prevalence Ratios

Background: We assessed the performance of CoronaCHEK lateral flow assay on samples from Uganda and Baltimore to determine the impact of geographic origin on assay performance. Methods: Serum samples from SARS-CoV-2 PCR+ individuals (Uganda: 78 samples from 78 individuals and Baltimore: 266 samples from 38 individuals) and from pre-pandemic individuals (Uganda 1077 and Baltimore 532) were evaluated. Prevalence ratios (PR) were calculated to identify factors associated with a false-positive test. Results: After first positive PCR in Ugandan samples the sensitivity was: 45% (95% CI 24,68) at 0-7 days; 79% (95%CI 64,91) 8-14 days; and 76% (95%CI 50,93) >15 days. In samples from Baltimore, sensitivity was: 39% (95% CI 30, 49) 0-7 days; 86% (95% CI 79,92) 8-14 days; and 100% (95% CI 89,100) 15 days post positive PCR. The specificity of 96.5% (95% CI 97.5,95.2) in Ugandan samples was significantly lower than samples from Baltimore 99.3% (95% CI 98.1,99.8), p<0.01. In Ugandan samples, individuals with a false positive result were more likely to be male (PR 2.04, 95% CI 1.03,3.69) or individuals who had a fever more than a month prior to sample acquisition (PR 2.87, 95% CI 1.12,7.35). Conclusions: Sensitivity of the CoronaCHEK was similar in samples from Uganda and Baltimore. The specificity was significantly lower in Ugandan samples than in Baltimore samples. False positive results in Ugandan samples appear to correlate with a recent history of a febrile illness, potentially indicative of a cross-reactive immune response in individuals from East Africa.

scholarly journals Differential Performance of CoronaCHEK SARS-CoV-2 Lateral Flow Antibody Assay by Geographic Origin of Samples

2021 ◽  
Author(s):  
Owen R. Baker ◽  
M. Kate Grabowski ◽  
Ronald M. Galiwango ◽  
Aminah Nalumansi ◽  
Jennifer Serwanga ◽  
...  
Keyword(s):  
False Positive ◽  
Geographic Origin ◽  
Febrile Illness ◽  
Lateral Flow ◽  
False Positive Test ◽  
Assay Performance ◽  
History Of ◽  
The Impact ◽  
Prevalence Ratios ◽  
Positive Results

Background: We assessed the performance of CoronaCHEK lateral flow assay on samples from Uganda and Baltimore to determine the impact of geographic origin on assay performance. Methods: Plasma samples from SARS-CoV-2 PCR+ individuals (Uganda: 78 samples from 78 individuals and Baltimore: 266 samples from 38 individuals) and from pre-pandemic individuals (Uganda 1077 and Baltimore 532) were evaluated. Prevalence ratios (PR) were calculated to identify factors associated with a false-positive test. Results: After first positive PCR in Ugandan samples the sensitivity was: 45% (95% CI 24,68) at 0-7 days; 79% (95%CI 64,91) 8-14 days; and 76% (95%CI 50,93) >15 days. In samples from Baltimore, sensitivity was: 39% (95% CI 30, 49) 0-7 days; 86% (95% CI 79,92) 8-14 days; and 100% (95% CI 89,100) 15 days post positive PCR. The specificity of 96.5% (95% CI 97.5,95.2) in Ugandan samples was significantly lower than samples from Baltimore 99.3% (95% CI 98.1,99.8), p<0.01. In Ugandan samples, individuals with a false positive result were more likely to be male (PR 2.04, 95% CI 1.03,3.69) or individuals who had a fever more than a month prior to sample acquisition (PR 2.87, 95% CI 1.12,7.35). Conclusions: Sensitivity of the CoronaCHEK was similar in samples from Uganda and Baltimore. The specificity was significantly lower in Ugandan samples than in Baltimore samples. False positive results in Ugandan samples appear to correlate with a recent history of a febrile illness, potentially indicative of a cross-reactive immune response in individuals from East Africa.

scholarly journals SAT-192 Eletriptan (RelpaxaTm) Causing False Positive Elevations in Urinary Metanephrine

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Zachary Bloomer ◽  
Nath Priti ◽  
Thanh Duc Hoang ◽  
Mohamed K M Shakir
Keyword(s):  
Blood Pressure ◽  
False Positive ◽  
Arterial Blood Flow ◽  
Positive Test ◽  
Uncontrolled Hypertension ◽  
False Positive Test ◽  
Arterial Blood ◽  
History Of ◽  
Plasma Metanephrines ◽  
Urine Metanephrines

Abstract Background: The diagnosis of pheochromocytoma depends crucially on the demonstration of excessive production of catecholamines. This step, however, is fraught with several difficulties, in particular with false-positive test results. Drugs such as phenoxybenzamine and tricyclic antidepressants are the most frequently associated causes for false-positive results. Other medications are also known to cause a false positive elevation of urinary metanephrines. We are reporting a patient with markedly elevated urine metanephrines associated with the use of Eletriptan hydrobromide (RelpaxaTM), a drug commonly used for treating migraine. Clinical Case: A 29-year-old man with a history of migraine managed on ibuprofen and recently started Eletriptan presented to the emergency room complaining of a 24-hour history of progressively worsening headaches. At the time of initial evaluation his blood pressure was in the 220s/160s with a creatinine of 1.9 mg/dL with unknown baseline. He was managed on an IV nicardipine drip. Due to his young age he underwent an evaluation for secondary causes of his hypertension. Laboratory: normal aldosterone/renin level (ratio was 0.4), normal midnight salivary cortisol and normal thyroid function studies. Urine screening for drug abuse was also negative. A 24-hour urine metanephrine level, while the patient was taking Eletriptan, was markedly elevated (normetanephrine 1341mcg (ref 82–500) and metanephrine level of 2494 mcg (ref 45–290). In contrast, the plasma metanephrines were only mildly elevated (metanephrines level 27 pg/ml (ref 0–62) and normetanephrine level of 255 pg/ml (ref 0–145)). Adrenal CT did not reveal any evidence of adrenal nodules. Additionally a Gallium-68 PET/CT scan did not reveal any evidence of pheochromocytoma or paraganglioma. Eletriptan was discontinued and his blood pressure was controlled on oral medications. Within one week of stopping Eletriptan his urine metanephrines (metanephrine 76 mcg/ 24 hrs, normetanephrine 277 mcg/dL) and plasma metanephrines (metanephrine 39 pg/mL, normetanephrine 148 pg/mL) normalized. Conclusion: The discrepancy between plasma and urine metanephrines in our patient suggests the possibility of a false positive test. Eletriptan, a second generation triptan drug, is a selective 5-hydroxytryptamine 1B/1D receptor agonist and has been shown to reduce carotid arterial blood flow, with only a small increase in arterial blood pressure at high doses. However, Eletriptan has no significant affinity or pharmacological activity at adrenergic α1, α2, or β; dopaminergic D1 or D2; muscarinic; or opioid receptors. It is also interesting to note that Eletriptan use is contraindicated in uncontrolled hypertension. It is possible Eletriptan may affect the assay of urine metanephrines. However, the exact mechanism of Eletriptan causing elevated urine metanephrines in our patient is not clear.

scholarly journals Occurrence of Aujeszky’s disease virus single-reactor pigs in Poland

2015 ◽  
Vol 59 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Andrzej Lipowski ◽  
Zygmunt Pejsak
Keyword(s):  
Disease Virus ◽  
False Positive ◽  
Serum Samples ◽  
Eradication Programme ◽  
Glycoprotein E ◽  
Aujeszky's Disease ◽  
Aujeszky’S Disease ◽  
Aujeszky’S Disease Virus ◽  
Negative Findings ◽  
History Of

AbstractThe aim of the study was to analyse the prevalence of single-reactor (SR) pigs in Poland, to attempt an explanation for this phenomenon, and to assess whether the occurrence of SR pigs could create problems for a successful Aujeszky’s disease virus (ADV) eradication programme in Poland. A total of 6494 ADV gE antibody positive/doubtful sera were retested by gB ELISA and subsequently by virus neutralisation test (VNT) to confirm the results of the glycoprotein E (gE) ELISA. Amongst the serum samples tested, 5.9% could be classified as being taken from SR pigs, as was shown by gE ELISA positive/doubtful results, which were not confirmed by negative findings in gB ELISA and VNT. It means that the observed SR phenomenon was due to a false positive/doubtful reaction in gE ELISA. This finding was strongly supported by the fact that the serum samples were taken from the animals from herds without any previous or subsequent history of Aujeszky’s disease. The low percentage of SR pigs does not seem to create a big obstacle to a successful ADV eradication programme in Poland.

scholarly journals Evaluation of the Performance of the IMMY sona Aspergillus Galactomannan Lateral Flow Assay When Testing Serum To Aid in Diagnosis of Invasive Aspergillosis

2020 ◽  
Vol 58 (6) ◽  
Author(s):  
P. Lewis White ◽  
Jessica S. Price ◽  
Raquel Posso ◽  
Morgan Cutlan-Vaughan ◽  
Lorna Vale ◽  
...  
Keyword(s):  
Invasive Aspergillosis ◽  
Roc Analysis ◽  
False Negative ◽  
Area Under The Curve ◽  
Invasive Fungal Disease ◽  
Lateral Flow ◽  
Optimal Threshold ◽  
Serum Samples ◽  
Simple Method ◽  
The Impact

ABSTRACT Management of invasive aspergillosis has been improved by biomarker assays, but limited accessibility and batch testing limit the impact. Lateral flow assays (LFA) are a simple method for use outside specialist centers, provided performance is acceptable. The objective of this study was to determine the performance of the recently released IMMY sona Aspergillus LFA when testing serum samples. The study took the form of a retrospective, anonymous case/control study comprising 179 serum samples from 136 patients with invasive fungal disease, previously documented using recently revised internationally accepted definitions. The LFA was performed following the manufacturer’s instructions using a cube reader to generate a galactomannan index (GMI). Performance parameters were determined, and receiver operator characteristic (ROC) analysis was used to identify an optimal threshold. Concordance with the Bio-Rad Aspergillus Ag assay (GM-EIA) was performed. At the recommended positivity threshold (GMI ≥ 0.5), LFA sensitivity and specificity were 96.9% (31/32) and 98% (98/100), respectively. ROC analysis confirmed the optimal threshold and generated an area under the curve of 0.9919. Qualitative agreement between LFA and GM-EIA was 89.0%, generating a Kappa statistic of 0.698, representing good agreement, with most discordance arising due to false-negative GM-EIA samples that were positive by LFA. The median GMI generated by the LFA was significantly greater than that generated by the GM-EIA. The IMMY sona Aspergillus LFA, when used with a cube reader, provides a rapid alternative to the well-established GM-EIA, potentially detecting more GM epitopes and enhancing sensitivity.

scholarly journals Covert cases of Severe Acute Respiratory Syndrome Coronavirus 2: An obscure but present danger in regions endemic for Dengue and Chikungunya viruses

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244937
Author(s):  
Lorenzzo Lyrio Stringari ◽  
Michel Norbim de Souza ◽  
Nésio Fernandes de Medeiros Junior ◽  
Jaqueline Pegoretti Goulart ◽  
Camila Giuberti ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Clinical Symptoms ◽  
Previous History ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Igg Antibody ◽  
Acute Infections ◽  
History Of ◽  
Chemiluminescent Microparticle Immunoassay ◽  
The Impact

Background The impact of SARS-CoV-2 in regions endemic for both Dengue and Chikungunya is still not fully understood. Considering that symptoms/clinical features displayed during Dengue, Chikungunya and SARS-CoV-2 acute infections are similar, undiagnosed cases of SARS-CoV-2 in co-endemic areas may be more prevalent than expected. This study was conducted to assess the prevalence of covert cases of SARS-CoV-2 among samples from patients with clinical symptoms compatible with either Dengue or Chikungunya viral infection in the state of Espírito Santo, Brazil. Methods Presence of immunoglobulin G (IgG) antibody specific to SARS-CoV-2 nucleoprotein was detected using a chemiluminescent microparticle immunoassay in samples from 7,370 patients, without previous history of COVID-19 diagnosis, suspected of having either Dengue (n = 1,700) or Chikungunya (n = 7,349) from December 1st, 2019 to June 30th, 2020. Findings Covert cases of SARS-CoV-2 were detected in 210 (2.85%) out of the 7,370 serum samples tested. The earliest undiagnosed missed case of COVID-19 dated back to a sample collected on December 18, 2019, also positive for Dengue Virus. Cross-reactivity with either Dengue virus or other common coronaviruses were not observed. Interpretation Our findings demonstrate that concomitant Dengue or Chikungunya outbreaks may difficult the diagnosis of SARS-CoV-2 infections. To our knowledge, this is the first study to demonstrate, with a robust sample size (n = 7,370) and using highly specific and sensitive chemiluminescent microparticle immunoassay method, that covert SARS-CoV-2 infections are more frequent than previously expected in Dengue and Chikungunya hyperendemic regions. Moreover, our results suggest that SAR-CoV-2 cases were occurring prior to February, 2020, and that these undiagnosed missed cases may have contributed to the fast expansion of SARS-CoV-2 outbreak in Brazil. Data presented here demonstrate that in arboviral endemic regions, SARS-CoV-2 infection must be always considered, regardless of the existence of a previous positive diagnosis for Dengue or Chikungunya.

scholarly journals Archived dengue serum samples produced false-positive results in SARS-CoV-2 lateral flow-based rapid antibody tests

2021 ◽  
Vol 70 (6) ◽  
Author(s):  
Himadri Nath ◽  
Abinash Mallick ◽  
Subrata Roy ◽  
Soumi Sukla ◽  
Keya Basu ◽  
...  
Keyword(s):  
Dengue Virus ◽  
False Positive ◽  
Lateral Flow ◽  
Accurate Estimation ◽  
Serum Samples ◽  
Positive Serum ◽  
Rapid Tests ◽  
Antibody Tests ◽  
Positive Results ◽  
Rapid Antibody

Co-endemicity of SARS-CoV-2 and dengue virus (DV) infection is becoming a matter of serious concern as it has been already reported that antibodies (Ab) elicited by SARS-CoV-2 infection can produce false-positive results in dengue IgG and IgM rapid tests and vice versa. Here we communicate that five of thirteen DV antibody-positive serum samples from Kolkata, archived in 2017 (predating the COVID-19 outbreak), produced false-positive results in SARS-CoV-2 IgG/IgM lateral flow-based rapid tests. Our results emphasize the importance of implementing tests with higher specificity to conduct sero-surveillance for accurate estimation of SARS-CoV-2/DV prevalence in regions where both viruses now co-exist.

scholarly journals Evaluation of Serum Cryptococcal Antigen Testing Using Two Novel Semiquantitative Lateral Flow Assays in Persons with Cryptococcal Antigenemia

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Caleb Skipper ◽  
Kiiza Tadeo ◽  
Emily Martyn ◽  
Elizabeth Nalintya ◽  
Radha Rajasingham ◽  
...  
Keyword(s):  
False Positive ◽  
Diagnostic Performance ◽  
False Negative ◽  
Lateral Flow ◽  
Reference Standard ◽  
Serum Samples ◽  
Cryptococcal Antigen ◽  
Negative Results ◽  
Lateral Flow Assays ◽  
Positive Results

ABSTRACT Early cryptococcal disease can be detected via circulating antigen in blood before fulminant meningitis develops, when early antifungal therapy improves survival. Two semiquantitative cryptococcal antigen (CrAg) lateral flow assays (LFAs) have been developed, but their diagnostic performance has not been defined. Cryopreserved serum samples from HIV-infected Ugandans obtained as part of a prospective CrAg-screening cohort were tested in duplicate for CrAg by the CrAgSQ (IMMY) and CryptoPS (Biosynex) lateral flow assays. Case-controlled diagnostic performance was measured using the FDA-approved CrAg LFA (IMMY) as a reference standard via McNemar’s test. Of 99 serum samples tested, 57 were CrAg positive (CrAg+) by the CrAg LFA reference standard. By CrAgSQ, 57 were read as positive, with 98% sensitivity (56/57; 95% confidence interval [CI], 0.91 to 0.99) and 98% specificity (41/42; 95% CI, 0.88 to 0.99) (McNemar’s, P = 0.99). The sample with a false-negative result by CrAgSQ (n = 1) had a titer of <1:5, while the sample with a false-positive result (n = 1) yielded a 1+ result. By CryptoPS, 52 samples were read as positive, with 88% sensitivity (50/57; 95% CI, 0.76 to 0.95) and 95% specificity (40/42; 95% CI, 0.84 to 0.99) (McNemar’s, P = 0.18). The CryptoPS false-negative results included samples with titers of <1:5 (n = 1), 1:5 (n = 5), and 1:20 (n = 1), while samples with false-positive results by CryptoPS (n = 2) yielded Positive results. The CryptoPS assay missed 35% (7/20) of samples with CrAg LFA titers of ≤1:20. The new semiquantitative CrAg LFAs allow rapid estimation of titer levels in easy-to-perform platforms. The CrAgSQ demonstrated better qualitative sensitivity and specificity than the CryptoPS compared to the reference standard. The exact grading of the CrAgSQ results has some subjectivity, with interreader variability; however, qualitative reads were generally concordant for both assays.

scholarly journals Unexpected False-Positive Rates in Pediatric SARS-CoV-2 Serology Using the EUROIMMUN Anti-SARS-CoV-2 ELISA IgG Assay

2021 ◽  
Author(s):  
Daniel Geisler ◽  
Megan Culler Freeman ◽  
Glenn J Rapsinski ◽  
Sarah E Wheeler
Keyword(s):  
Performance Studies ◽  
False Positive ◽  
Pediatric Population ◽  
Serum Samples ◽  
Population Prevalence ◽  
False Positivity ◽  
Assay Performance ◽  
Improve Accuracy ◽  
Pediatric Populations ◽  
Serologic Assay

Abstract Objectives Serologic assay performance studies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-​2) in pediatric populations are lacking, and few seroprevalence studies have routinely incorporated orthogonal testing to improve accuracy. Methods Remnant serum samples for routine bloodwork from 2,338 pediatric patients at UPMC Children’s Hospital of Pittsburgh were assessed using the EUROIMMUN Anti-SARS-CoV-2 ELISA IgG (EuroIGG) assay. Reactive cases with sufficient volume were also tested using 3 additional commercial assays. Results Eighty-five specimens were reactive according to the EuroIGG, yielding 3.64% (95% confidence interval [CI], 2.91%-4.48%) seropositivity, of which 73 specimens had sufficient remaining volume for confirmation by orthogonal testing. Overall, 19.18% (95% CI, 10.18%-28.18%) of samples were positive on a second and/or third orthogonal assay. This 80.82% false positivity rate is disproportionate to the expected false positivity rate of 50% given our pediatric population prevalence and assay performance. Conclusions In pediatric populations, false-positive SARS-CoV-2 serology may be more common than assay and prevalence parameters would predict, and further studies are needed to establish the performance of SARS-CoV-2 serology in children.

Investigating the Relationship Between Self-Esteem and Stigma Among Young Adults With History of Suicide Attempts

Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder
Keyword(s):  
Young Adults ◽  
Suicide Attempts ◽  
Self Esteem ◽  
High Risk Population ◽  
High Functioning ◽  
People With Mental Illness ◽  
History Of ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.

The Film World’s Cooperative Store: Institutions and Films of the 1930s and 1940s

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
World War Ii ◽  
Meat Products ◽  
Public Information ◽  
Early History ◽  
World War ◽  
International Context ◽  
German Occupation ◽  
History Of ◽  
The Uk ◽  
The Impact

This chapter traces the early history of state-sponsored informational filmmaking in Denmark, emphasising its organisation as a ‘cooperative’ of organisations and government agencies. After an account of the establishment and early development of the agency Dansk Kulturfilm in the 1930s, the chapter considers two of its earliest productions, both process films documenting the manufacture of bricks and meat products. The broader context of documentary in Denmark is fleshed out with an account of the production and reception of Poul Henningsen’s seminal film Danmark (1935), and the international context is accounted for with an overview of the development of state-supported filmmaking in the UK, Italy and Germany. Developments in the funding and output of Dansk Kulturfilm up to World War II are outlined, followed by an account of the impact of the German Occupation of Denmark on domestic informational film. The establishment of the Danish Government Film Committee or Ministeriernes Filmudvalg kick-started aprofessionalisation of state-sponsored filmmaking, and two wartime public information films are briefly analysed as examples of its early output. The chapter concludes with an account of the relations between the Danish Resistance and an emerging generation of documentarists.

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