Comparison of Serological Tests for the Detection of Natural Heartworm Infection in Cats

2004 ◽  
Vol 40 (5) ◽  
pp. 376-384 ◽  
Author(s):  
Paul Berdoulay ◽  
Julie K. Levy ◽  
Patti S. Snyder ◽  
Michael J. Pegelow ◽  
Jennifer L. Hooks ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Serological Tests ◽  
Male Worm ◽  
Single Male ◽  
Commercial Laboratory ◽  
Heartworm Infection ◽  
Antigen Tests ◽  
Antibody Tests ◽  
Positive Results

Serological tests were performed on 380 cats with necropsy-confirmed heartworm status to compare the performance of currently available commercial laboratory and point-of-care heart-worm serological tests in a heartworm-endemic area. Overall, antigen tests detected 79.3% to 86.2% of heartworm infections and were highly specific. Most cats with false-negative antigen tests had a single male worm. Antibody tests detected 62.1% to 72.4% of heartworm infections and had a wider range of false-positive results (1.4% to 19.1%) than antigen tests (0.3% to 2.0%). Serological tests for feline heartworm infection varied in diagnostic performance. Combining results from antigen and antibody tests achieved greater sensitivity than using either test alone.

scholarly journals Automated, flow-based chemiluminescence microarray immunoassay for the rapid multiplex detection of IgG antibodies to SARS-CoV-2 in human serum and plasma (CoVRapid CL-MIA)

2021 ◽  
Author(s):  
Julia Klüpfel ◽  
Rosa Carolina Koros ◽  
Kerstin Dehne ◽  
Martin Ungerer ◽  
Silvia Würstle ◽  
...  
Keyword(s):  
Human Serum ◽  
False Negative ◽  
Igg Antibodies ◽  
Serological Tests ◽  
The Face ◽  
Microarray Immunoassay ◽  
Sample Set ◽  
Individual Immunity ◽  
Antibody Tests ◽  
Positive Results

AbstractIn the face of the COVID-19 pandemic, the need for rapid serological tests that allow multiplexing emerged, as antibody seropositivity can instruct about individual immunity after an infection with SARS-CoV-2 or after vaccination. As many commercial antibody tests are either time-consuming or tend to produce false negative or false positive results when only one antigen is considered, we developed an automated, flow-based chemiluminescence microarray immunoassay (CL-MIA) that allows for the detection of IgG antibodies to SARS-CoV-2 receptor-binding domain (RBD), spike protein (S1 fragment), and nucleocapsid protein (N) in human serum and plasma in less than 8 min. The CoVRapid CL-MIA was tested with a set of 65 SARS-CoV-2 serology positive or negative samples, resulting in 100% diagnostic specificity and 100% diagnostic sensitivity, thus even outcompeting commercial tests run on the same sample set. Additionally, the prospect of future quantitative assessments (i.e., quantifying the level of antibodies) was demonstrated. Due to the fully automated process, the test can easily be operated in hospitals, medical practices, or vaccination centers, offering a valuable tool for COVID-19 serosurveillance.

scholarly journals False-Negative Results in Point-of-Care Qualitative Human Chorionic Gonadotropin (hCG) Devices Due to Excess hCGβ Core Fragment

2009 ◽  
Vol 55 (7) ◽  
pp. 1389-1394 ◽  
Author(s):  
Ann M Gronowski ◽  
Mark Cervinski ◽  
Ulf-Håkan Stenman ◽  
Alison Woodworth ◽  
Lori Ashby ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Point Of Care ◽  
False Negative ◽  
The Core ◽  
Core Fragment ◽  
Negative Results ◽  
False Negative Results ◽  
Positive Results ◽  
Urine Specimens

Abstract Background: During pregnancy, human chorionic gonadotropin (hCG) immunoreactivity in urine consists of intact hCG as well as a number of hCG variants including the core fragment of hCGβ (hCGβcf). We identified 3 urine specimens with apparent false-negative results using the OSOM® hCG Combo Test (Genzyme Diagnostics) qualitative hCG device and sought to determine whether an excess of 1 of the fragments or variants might be the cause of the interference. Methods: We measured concentrations of hCG variants in the urine from 3 patients with apparent false-negative hCG results. Purified hCG variants were added to urines positive for hCG and tested using the OSOM, ICON® 25 hCG (Beckman Coulter), and hCG Combo SP® Brand (Cardinal Health) devices. Results: Dilution of these 3 urine samples resulted in positive results on the OSOM device. Quantification of hCG variants in each of the 3 patient urine specimens demonstrated that hCGβcf occurred in molar excess of intact hCG. Addition of purified hCGβcf to hCG-positive urines caused false-negative hCG results using the OSOM and ICON qualitative urine hCG devices. Conclusions: Increased concentrations of hCGβcf can cause false-negative results on the OSOM and ICON qualitative urine hCG devices. .

scholarly journals Performance of SARS-CoV-2 Serology tests: Are they good enough?

2020 ◽  
Author(s):  
Isabelle Piec ◽  
Emma English ◽  
M Annette Thomas ◽  
Samir Dervisevic ◽  
William D Fraser ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Respiratory Infections ◽  
Point Of Care ◽  
False Negative ◽  
Rapid Test ◽  
Diagnostic Sensitivity ◽  
Medical Community ◽  
Antibody Detection ◽  
Serological Tests ◽  
Negative Results

AbstractBackgroundIn the emergency of the SARS-CoV-2 pandemic, great efforts were made to quickly provide serology testing to the medical community however, these methods have been introduced into clinical practice without the complete validation usually required by the regulatory organizations.MethodsSARS-CoV-2 patient samples (n=43) were analysed alongside pre-pandemic control specimen (n=50), confirmed respiratory infections (n=50), inflammatory polyarthritis (n=22) and positive for thyroid stimulating immunoglobulin (n=30). Imprecision, diagnostic sensitivity and specificity and concordance were evaluated on IgG serologic assays from EuroImmun, Epitope Diagnostics (EDI), Abbott Diagnostics and DiaSorin and a rapid IgG/IgM test from Healgen.ResultsEDI and EuroImmun imprecision was 0.02-14.0% CV. Abbott and DiaSorin imprecision (CV) ranged from 5.2% - 8.1% and 8.2% - 9.6% respectively. Diagnostic sensitivity of the assays were 100% (CI: 80-100%) for Abbott, EDI and EuroImmun and 95% (CI: 73-100%) for DiaSorin at ≥14 days post PCR. Only the Abbott assay had a diagnostic specificity of 100% (CI: 91-100%). EuroImmun cross-reacted in 3 non-SARS-CoV-2 respiratory infections and 2 controls. The DiaSorin displayed more false negative results and cross-reacted in six cases across all conditions tested. EDI had one cross-reactive sample. The Healgen rapid test showed excellent sensitivity and specificity. Overall, concordance of the assays ranged from 76.1% to 97.9%.ConclusionsSerological tests for SARS-CoV-2 showed good analytical performance. The head-to-head analysis of samples revealed differences in results that may be linked to the use of nucleocapsid or spike proteins. The point of care device tested demonstrated adequate performance for antibody detection.

scholarly journals Identification of etiological agents of selected bacterial and viral infections based on serological tests

2018 ◽  
Vol 72 ◽  
pp. 1162-1178
Author(s):  
Aleksandra Lewandowicz-Uszyńska ◽  
Piotr Naporowski ◽  
Gerard Pasternak ◽  
Danuta Witkowska
Keyword(s):  
False Positive ◽  
Cellular Response ◽  
Bacterial Infections ◽  
Viral Infections ◽  
False Negative ◽  
Main Role ◽  
Serological Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Positive Results

The human immune system’s response to infection is closely related with the type of pathogen. First, a rapid, metabolically inexpensive and non-specific innate immunity is induced, then a specific acquired immunity is activated. In bacterial infections caused by intracellular pathogens, the main role is played by cellular response. In infections caused by bacterial extracellular pathogens, a crucial role is played by antibodies. The clinical symptoms of bacterial and viral infections very often are similar, which is why diagnosing them based only on medical history and physical examination is insufficient. To identify the etiological factors of infections differentiating media, biochemical tests, molecular methods and serological tests are used. The detection of microorganisms or their genetic material can be performed within a short time after the occurrence of an infection. The detection of antibodies is possible only in the appropriate time called the serological window. In a serological diagnostic of infections there are problems with an appropriate interpretation of obtained results. Cross-reactivity can give false positive results for the diagnosis of Chlamydophila pneumonia infection. The problem with the detection of Borrelia burgdorferi infection can be caused by a simultaneous coinfection with different spirochetes, syphilis, mononucleosis or HIV. In serological diagnostics of bacterial infections, the administration of antibiotics to patients before taking serum samples can be responsible for false negative results. Another reason for such results can be a weak humoral response in infected patients. In viral infections, false positive results can be caused by a coinfection of different viruses, especially from the same family or by bacterial or protozoal coinfections or by autoimmune diseases. False-negative results in viral infections often are caused by the early phase of an infection. To properly recognize an etiological factor of infection it is necessary to use an appropriate method, precision of test and collect samples at the appropriate time.

scholarly journals Towards effective diagnostic assays for COVID-19: a review

2020 ◽  
Vol 73 (7) ◽  
pp. 370-377 ◽  
Author(s):  
Marietjie Venter ◽  
Karin Richter
Keyword(s):  
Point Of Care ◽  
Case Definition ◽  
Molecular Diagnostic ◽  
Public Health Response ◽  
Serological Tests ◽  
Diagnostic Assays ◽  
Laboratory Capacity ◽  
Health Response ◽  
The Usa ◽  
Antigen Tests

Countries globally are affected by the COVID-19 pandemic, with nearly two million cases and 120 000 deaths occurring within 4 months of the discovery of the severe acute respiratory syndrome coronavirus-2 in December 2019 in China. Accurate diagnoses of cases is key in managing the pandemic by identification, isolation and treatment of patients and defining the epidemiology of the virus. By mid-January 2020, a scientist from China published the full genome of the virus, which facilitated the development of accurate molecular diagnostic assays. By the end of January 2020, the WHO, in collaboration with laboratories in Asia, Europe and the USA, published several real-time reverse transcriptase PCR (rtRT-PCR) protocols that allowed identification of cases and development of commercial assays. Clinical investigations facilitated development of accurate case definition and guidance for laboratories on the optimum specimens and procedures for diagnoses. Currently, laboratory-based rtRT-PCR is the recommended test for diagnoses of acute cases to ensure patients can be identified and isolated and to facilitate the public health response. However, due to delays in diagnoses, severe shortage of tests and laboratory capacity, point-of-care molecular or antigen tests are becoming more attractive. Although serological tests are not suitable for diagnoses of acute cases, they are important to define epidemiological questions, including attack rate in the population, and to identify immune individuals. This review aimed to summarise the current available information for diagnoses of cases and to aid laboratories and healthcare workers to select the best assays and procedures.

scholarly journals SARS-CoV-2 laboratory diagnostic methods: a systematic review

2021 ◽  
Vol 31 (Supplement_2) ◽  
Author(s):  
Rúben Nunes ◽  
Carolina Melo ◽  
Diana Martins ◽  
Fernando Mendes
Keyword(s):  
Systematic Review ◽  
Point Of Care ◽  
False Negative ◽  
Culture Technique ◽  
Diagnostic Methods ◽  
Blood Collection ◽  
Medical Subject Headings ◽  
Serological Tests ◽  
Detection Rates ◽  
Specimen Handling

Abstract Background The new SARS-CoV-2 is a single-stranded RNA β-coronavirus, and it is comprising by structural proteins (N), (S), (E) and (M). Timely and accurate detection is necessary for spread control of SARS-CoV-2 infection, avoiding inaccurate outcomes. Therefore, in this systematic review, it is purpose to evaluate a set of laboratory diagnostic techniques and methods, analyse their specificity, sensitivity, contributing to improve detection rates and reduce false negative and false positive diagnostic results. Methods In this review, we used literature available on the indexed search database ‘PubMed’, concerning the following keywords: ‘SARS-CoV-2’, ‘Specimen handling’, ‘Cell Culture Technique’, ‘Viral Antigen’, ‘Immunoassay’, ‘NAAT’ according to Medical Subject Headings Mesh and applying the Prisma Diagram methodology. Results DD-PCR and CRISPER had more promising results, but they are unconventional and expensive NAAT methods, the usage of the target RdRp/He gene has exhibited very encouraging results improving sensitivity and specificity. After the onset of symptoms, the sensitivity of the immunoassay varies considering of blood collection day. The antigen detection test showed the highest specificity reached, however is sensitivity is lower compared to NAAT assays. Conclusions In summary, RT-PCR still considered the gold standard and precisely detects the presence of virus RNA, although with some flaws in sensitivity, while the serological tests identify a previous infection by the virus, detecting antibodies, allowing the kinetic and immunological studies, not being able to use as a diagnostic method. The molecular point of care testing equipment’s revelled be the future in the rapid and accurately diagnosis of SARS-CoV-2.

scholarly journals At-home self-testing of teachers with a SARS-CoV-2 rapid antigen test to reduce potential transmissions in schools

2020 ◽  
Author(s):  
Sebastian Hoehl ◽  
Barbara Schenk ◽  
Olga Rudych ◽  
Stephan Göttig ◽  
Ivo Foppa ◽  
...  
Keyword(s):  
False Positive ◽  
High Frequency ◽  
False Negative ◽  
Study Participant ◽  
Lower Sensitivity ◽  
Antigen Test ◽  
Rt Pcr ◽  
Antigen Tests ◽  
Positive Results ◽  
At Home

AbstractBackgroundRapid antigen tests for SARS-CoV-2 became available recently, offering an opportunity to vastly increase testing capacities. Antigen tests offer lower sensitivity than the gold standard, RT-PCR, but rapid sample-to-answer time. High-frequency testing with an antigen test may offset the lower sensitivity, and testing can be done with at-home collection of samples, offering potential benefit in screening efforts. In this study, we set out to evaluate the practical application of self-performed high-frequency antigen test in a school setting.MethodA total of 711 teachers from 86 schools were enrolled in a seven-week study. After instruction, participants tested themselves every 48 hours at home with a rapid antigen test for SARS-CoV-2 (target: nucleocapsid protein) in a self-collected anterior nasal swab. Positive results in the antigen test were confirmed via RT-PCR from the same sample that had been determined to be positive by the study participant. A questionnaire was given to all participants to evaluate whether the test failed to detect infection.Findings10 836 tests from 602 teachers were recorded and analyzed. A total of five confirmed cases of viral shedding of SARS-CoV-2 was detected by use of the antigen test. One study participant with a SARS-CoV-2 infection was presymptomatic and four were mildly symptomatic at the time of the antigen test. Sixteen false positive antigen tests (0.15% of all tests) were reported, predominantly when the local incidence in the general population was low. In four cases, the study participant reported that a PCR had detected a SARS-CoV-2 infection, but the antigen test was negative, indicating a false negative result.InterpretationHigh-frequency, self-performed rapid antigen tests can detect individuals with a SARS-CoV-2 infection, and therefore potentially reduce transmissions. Testing may be most beneficial when applied during high local incidence of SARS-CoV-2 infections and when mild or atypical symptoms are present. To avoid a high rate of false positive results, a test with optimized specificity should be used.FundingThe study was commissioned and funded by the Hessian Ministry of Education and the Hessian Ministry of Integration and Social Affairs.

scholarly journals The role of rapid diagnostic point of care IgG/IgM antibody tests in the diagnosis of SARS-CoV-2 infection

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Nishita Tripathi ◽  
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Clinical Importance ◽  
Antibody Test ◽  
High Specificity ◽  
Nucleic Acid Amplification ◽  
Serological Tests ◽  
Nucleic Acid Amplification Tests ◽  
Igm Antibody ◽  
Antibody Tests

Background: Current testing of symptomatic patients for SARS-CoV-2 involves the use of nucleic acid amplification tests, also known as genetic, RNA or PCR to detect viral RNA. The initial use of point-of-care (POC) antibody tests, also known as serological tests in the management of SARS-CoV-2 infection was limited. In this review, we determine the significance of POC antibody serological tests and explore their possible role in the diagnosis and management of patients infected with SARS-CoV-2 virus. Methods: A literature search was conducted in Google Scholar, PubMed, and Embase, and supplemented by searching the Center for Disease Control (CDC), and the Infectious Diseases Society of America (IDSA) websites. We identified 7 articles published in the last 6 months pertaining to the keywords. The sensitivity and specificity of the IgG/IgM antibody tests obtained from these studies were compared and used to determine the clinical importance of the rapid diagnostic antibody test in SARS-CoV-2 infection. Results: Through the literature review, it was found that POC diagnostic antibody tests can be used as an adjuvant with the nucleic acid amplification tests in determining both active and post-exposure antibodies. These rapid antibody IgG/IgM tests had high sensitivity, the ability of a test to correctly identify those with the disease, and high specificity, the ability of the test to correctly identify those without the disease. Conclusion: Emerging studies indicate the importance of POC antibody serological testing as an important diagnostic tool in the current SARS-CoV-2 pandemic. Considering the limitations of the molecular methods of testing, POC antibody tests can help reduce dependency on the molecular assays of testing when used in conjunction with them.

scholarly journals Celiac Disease and Immunoglobulin A Deficiency: How Effective Are the Serological Methods of Diagnosis?

2002 ◽  
Vol 9 (6) ◽  
pp. 1295-1300 ◽  
Author(s):  
V. Kumar ◽  
M. Jarzabek-Chorzelska ◽  
J. Sulej ◽  
Krystyna Karnewska ◽  
T. Farrell ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Pediatric Patients ◽  
Tissue Transglutaminase ◽  
False Negative ◽  
Immunoglobulin A ◽  
Iga Deficiency ◽  
Igg Antibodies ◽  
Serological Tests ◽  
Asymptomatic Patients ◽  
Antibody Tests

ABSTRACT Immunoglobulin A (IgA) deficiency is 10 to 15 times more common in patients with celiac disease (CD) than in healthy subjects. Serological tests have become the preferred methods of diagnosing CD in both symptomatic and asymptomatic patients. However, commercially available serological methods are limited in that they detect only the IgA isotype of antibodies (with the exception of IgG gliadin assays); hence, IgA-deficient patients with CD may yield false-negative serology. Fifteen pediatric patients with CD and 10 IgA-deficient pediatric patients without CD were examined for IgA and IgG antibodies to endomysium, gliadin, and tissue transglutaminase. Twenty-five specimens from patients with IgA deficiency were examined. Fifteen were from patients with CD, and 10 were patients without CD. All 15 IgA-deficient patients with CD were positive for endomysium antibodies of the IgG isotype and for IgG gliadin antibodies. All but one of the IgA-deficient patients with CD were also positive for IgG tissue transglutaminase antibodies. None of the IgA-deficient patients without CD were positive for any of the antibody markers. All the specimens examined were also negative for IgA-specific antibodies to endomysium, gliadin, and tissue transglutaminase. IgG-specific antibody tests for endomysium, gliadin, and tissue transglutaminase are useful for the identification of IgA-deficient patients with CD. IgG antibody tests along with tests routinely being used in clinical laboratories can reliably detect all active patients with CD. In addition, the levels of these CD-specific IgG antibodies could be used to monitor patient dietary compliance.

scholarly journals Evaluation of two rapid antigen tests to detect SARS-CoV-2 in a hospital setting

2021 ◽  
Author(s):  
Andreas Osterman ◽  
Hanna-Mari Baldauf ◽  
Marwa Eletreby ◽  
Jochen M. Wettengel ◽  
Suliman Q. Afridi ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Hospital Setting ◽  
Outcome Data ◽  
Large Set ◽  
Antigen Test ◽  
University Hospitals ◽  
Clinical Sensitivity ◽  
Antigen Tests ◽  
The Impact

AbstractSuccessful containment strategies for the SARS-CoV-2 pandemic will depend on reliable diagnostic assays. Point-of-care antigen tests (POCT) may provide an alternative to time-consuming PCR tests to rapidly screen for acute infections on site. Here, we evaluated two SARS-CoV-2 antigen tests: the STANDARD™ F COVID-19 Ag FIA (FIA) and the SARS-CoV-2 Rapid Antigen Test (RAT). For diagnostic assessment, we used a large set of PCR-positive and PCR-negative respiratory swabs from asymptomatic and symptomatic patients and health care workers in the setting of two University Hospitals in Munich, Germany, i.e. emergency rooms, patient care units or employee test centers. For FIA, overall clinical sensitivity and specificity were 45.4% (n = 381) and 97.8% (n = 360), respectively, and for RAT, 50.3% (n = 445) and 97.7% (n = 386), respectively. For primary diagnosis of asymptomatic and symptomatic individuals, diagnostic sensitivities were 60.9% (FIA) (n = 189) and 64.5% (RAT) (n = 256). This questions these tests’ utility for the reliable detection of acute SARS-CoV-2-infected individuals, in particular in high-risk settings. We support the proposal that convincing high-quality outcome data on the impact of false-negative and false-positive antigen test results need to be obtained in a POCT setting. Moreover, the efficacy of alternative testing strategies to complement PCR assays must be evaluated by independent laboratories, prior to widespread implementation in national and international test strategies.

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