scholarly journals Tandem Use of OvMANE1 and Ov-16 ELISA Tests Increases the Sensitivity for the Diagnosis of Human Onchocerciasis

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1284
Author(s):  
Cabirou Mounchili Shintouo ◽  
Stephen Mbigha Ghogomu ◽  
Robert Adamu Shey ◽  
An Hotterbeekx ◽  
Emel Yagmur ◽  
...  
Keyword(s):  
Democratic Republic Of Congo ◽  
Serological Test ◽  
Antibody Test ◽  
Onchocerca Volvulus ◽  
Serum Samples ◽  
Positive Skin ◽  
Travel History ◽  
Control Programs ◽  
Potential Biomarker ◽  
Antibody Tests

The current serological test for human onchocerciasis relies on IgG4 reactivity against the parasite Ov-16 antigen, with reported sensitivities of only 60–80%. As control programs move from control to elimination, it is imperative to identify novel molecules that could improve the serodiagnosis reliability of this disease. In this study we compared the sensitivity of total IgG against OvMANE1—a chimeric antigen previously identified as a potential biomarker of human onchocerciasis—with that of an Ov-16 antibody test to detect an Onchocerca volvulus infection in persons presenting with microfilaria in skin snips. One hundred and ninety serum samples were obtained from persons with epilepsy in an onchocerciasis-endemic area at Ituri in the Democratic Republic of Congo where ivermectin has never been distributed. Fifty-nine (31.1%) samples were from individuals with a positive skin snip test; 41 (69.5%) of these 59 samples were positive with the OvMANE1 test and 41 (69.5%) with the Ov-16 test; 30 (50.8%) samples were positive for both tests and in 52 (88.1%) at least one of the tests was positive. Testing the 131 sera from persons with a negative skin snip result revealed that 63 (48.1%) were positive exclusively with the OvMANE1 test, 13 (9.9%) exclusively with the Ov-16 test and 25 (19.1%) with both tests. Nine European samples from individuals without past travel history in onchocerciasis endemic zones and 15 samples from Rwanda, a hypoendemic country for onchocerciasis were all negative for the OvMANE1 and Ov-16 tests. However, the specificity of both tests was difficult to determine due to the lack of a gold standard for antibody tests. In conclusion, the tandem use of OvMANE1 and Ov-16 tests improves the sensitivity of detecting Onchocerca volvulus seropositive individuals but, the OvMANE1 test needs to be further evaluated on samples from a population infected with other helminths to cautiously address its specificity.

scholarly journals Evaluation of Three Commercial SARS-CoV-2 Serologic Assays and Their Performance in Two-Test Algorithms

2020 ◽  
Vol 59 (1) ◽  
pp. e01892-20 ◽  
Author(s):  
Sarah E. Turbett ◽  
Melis Anahtar ◽  
Anand S. Dighe ◽  
Wilfredo Garcia Beltran ◽  
Tyler Miller ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Predictive Value ◽  
Antibody Test ◽  
Spike Protein ◽  
Serum Samples ◽  
Public Health Decision ◽  
Health Decision ◽  
Test Algorithm ◽  
The Individual ◽  
Antibody Tests

ABSTRACTSensitive and specific severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic assays are needed to inform diagnostic, therapeutic, and public health decision-making. We evaluated three commercial serologic assays as stand-alone tests and as components of two-test algorithms. Two nucleocapsid antibody tests (Abbott IgG and Roche total antibody) and one spike protein antibody test (DiaSorin IgG) were included. We assessed sensitivity using 128 serum samples from symptomatic PCR-confirmed coronavirus disease 2019 (COVID-19)-infected patients and specificity using 1,204 samples submitted for routine serology prior to COVID-19’s emergence, plus 64 pandemic-era samples from SARS-CoV-2 PCR-negative patients with respiratory symptoms. Assays were evaluated as stand-alone tests and as components of a two-test algorithm in which positive results obtained using one assay were verified using a second assay. The two nucleocapsid antibody tests were more sensitive than the spike protein antibody test overall (70% and 70% versus 57%; P ≤ 0.003), with pronounced differences observed using samples collected 7 to 14 days after symptom onset. All three assays were comparably sensitive (≥89%; P ≥ 0.13) using samples collected >14 days after symptom onset. Specificity was higher using the nucleocapsid antibody tests (99.3% and 99.7%) than using the spike protein antibody test (97.8%; P ≤ 0.002). When any two assays were paired in a two-test algorithm, the specificity was 99.9% (P < 0.0001 to 0.25 compared with the individual assays), and the positive predictive value (PPV) improved substantially, with a minimal effect on the negative predictive value (NPV). In conclusion, two nucleocapsid antibody tests outperformed a spike protein antibody test. Pairing two different serologic tests in a two-test algorithm improves the PPV, compared with the individual assays alone, while maintaining the NPV.

scholarly journals Ivermectin Treatment Response in Onchocerca Volvulus Infected Persons with Epilepsy: A Three-Country Short Cohort Study

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 617
Author(s):  
Alfred Dusabimana ◽  
Dan Bhwana ◽  
Stephen Raimon ◽  
Bruno P. Mmbando ◽  
An Hotterbeekx ◽  
...  
Keyword(s):  
Democratic Republic Of Congo ◽  
Geometric Mean ◽  
Infection Intensity ◽  
Post Treatment ◽  
Onchocerca Volvulus ◽  
Ivermectin Treatment ◽  
Positive Skin ◽  
History Of ◽  
Pre Treatment ◽  
Study Sites

Despite a long history of community-directed treatment with ivermectin (CDTI), a high ongoing Onchocerca volvulus transmission is observed in certain onchocerciasis-endemic regions in Africa with a high prevalence of epilepsy. We investigated factors associated with higher microfilarial (mf) density after ivermectin treatment. Skin snips were obtained from O. volvulus-infected persons with epilepsy before, and 3 to 5 months after ivermectin treatment. Participants were enrolled from 4 study sites: Maridi (South Sudan); Logo and Aketi (Democratic Republic of Congo); and Mahenge (Tanzania). Of the 329 participants, 105 (31.9%) had a post-treatment mf density >20% of the pre-treatment value. The percentage reduction in the geometric mean mf density ranged from 69.0% (5 months after treatment) to 89.4% (3 months after treatment). A higher pre-treatment mf density was associated with increased probability of a positive skin snip after ivermectin treatment (p = 0.016). For participants with persistent microfiladermia during follow-up, a higher number of previous CDTI rounds increased the odds of having a post-treatment mf density >20% of the pre-treatment value (p = 0.006). In conclusion, the high onchocerciasis transmission in the study sites may be due to initially high infection intensity in some individuals. Whether the decreasing effect of ivermectin with increasing years of CDTI results from sub-optimal response mechanisms warrants further research.

scholarly journals Evaluation of the Abbott Architect, Roche Elecsys and Virtus S1 SARS-CoV-2 antibody tests in community-managed COVID-19 cases

2020 ◽  
Author(s):  
Sebastian L. Johnston ◽  
Paul F McKay ◽  
Tatiana Kebadze ◽  
Kai Hu ◽  
Karnyart Samnuan ◽  
...  
Keyword(s):  
Antibody Test ◽  
Research Centre ◽  
Strong Positive Correlation ◽  
True Positive ◽  
Antibody Testing ◽  
Serum Samples ◽  
True Negative ◽  
Health And Social Care ◽  
Antibody Tests ◽  
Abbott Architect

AbstractBackgroundAntibody testing can help define how protective immunity to SARS-CoV-2 is and how long this immunity lasts. Many antibody tests have been evaluated in hospitalised rather than community based COVID-19 cases. Virtus Respiratory Research Ltd (Virtus) has developed its own quantitative IgM and IgG SARS CoV-2 antibody assay. We report its validation and performance characteristics and compare its performance with the Abbott Architect and Roche Elecsys assays in community COVID cases.MethodsWe developed a quantitative antibody test to detect IgM and IgG to the SARS-CoV-2 S1 spike protein (the Virtus test) and validated this test in 107 “true positive” sera from 106 community-managed and 1 hospitalised COVID-19 cases and 208 “true negative” serum samples. We validated the Virtus test against a neutralising antibody test. We determined sensitivities of the Abbott test in the 107 true positive samples and the Roche test in a subset of 75 true positive samples.ResultsThe Virtus quantitative test was positive in 93 of 107 (87%) community cases of COVID-19 and both IgM and IgG levels correlated strongly with neutralising antibody titres (r=0.75 for IgM, r=0.71 for IgG, P<0.0001 for both antibodies). The specificity of the Virtus test was 98.6% for low level antibody positives, 99.5% for moderate positives and 100% for high or very high positives. The Abbott test had a sensitivity of 68%. In the 75 sample subset, the Virtus test was positive in 91%, the Roche test in 69%.ConclusionsThe Abbott and Roche tests had sensitives of 68% and 69% respectively in this community set of COVID-19 sera, while the Virtus test had sensitivities of 87% and 91% in the same sample sets. The strong positive correlation with virus neutralization suggests a positive Virtus quantitative antibody test is likely predictive of protective against recurrent COVID-19.FundingThe development of the Virtus test and sample testing with all antibody tests was funded by Virtus Respiratory Research Ltd. The research studies providing 111 of the 208 of the “true negative” samples was supported by MRC Grant numbers MR/M025330/1 and G1100238 and by the National Institute of Health Research (NIHR) Imperial Biomedical Research Centre (BRC), SLJ is a NIHR Emeritus Senior Investigator and is funded in part by European Research Council Advanced Grant 788575 and the Asthma UK Clinical Chair (grant CH11SJ). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

scholarly journals EXPRESS: Evaluation of usability of various rapid antibody tests in diagnostic application for COVID-19

2020 ◽  
pp. 000456322098482
Author(s):  
Yoshifumi Uwamino ◽  
Masatoshi Wakui ◽  
Wataru Aoki ◽  
Toshinobu Kurafuji ◽  
Emmy Yanagita ◽  
...  
Keyword(s):  
Antibody Test ◽  
Antibody Detection ◽  
Rt Pcr ◽  
Serum Samples ◽  
Quantitative Test ◽  
Pcr Diagnosis ◽  
Rapid Tests ◽  
Chemiluminescent Immunoassay ◽  
Antibody Tests ◽  
Rapid Antibody

Background: The usability of laboratory tests related to SARS-CoV-2 is critically important for the world undergoing the COVID-19 pandemic. The present study aimed to assess diagnostic usability of rapid tests for detection of antibody against SARS-CoV-2 through comparison of their results with results of RT-PCR test for detection of SARS-CoV-2 genomic RNA and with results of a quantitative test for antibody detection. Methods: Serum samples were collected from eighteen patients undergoing RT-PCR testing for SARS-CoV-2. Twelve patients were RT-PCR positive while six were negative. A quantitative test based on chemiluminescent immunoassay and three rapid tests based on immunochromatography were performed to detect anti-SARS-CoV-2 IgG and IgM. Results: All the antibody tests exhibited poor sensitivity at the timing of initial RT-PCR diagnosis. IgG responses occurring prior to or simultaneously with IgM responses were observed through not only the quantitative test but also the three rapid tests. Based on concordance with the quantitative test results, the large variance among the three rapid tests was revealed. Conclusions: All antibody tests were unsatisfactory to replace RT-PCR for early diagnosis of COVID-19. Rapid antibody tests as well as a quantitative antibody test were useful in assessment of immune responses in COVID-19. The obvious variance among the three rapid tests suggested limited accuracy and difficult standardization. Diagnostic usability of rapid antibody tests for COVID-19 should be investigated rigorously.

scholarly journals Sphingolipid Analysis Indicate Lactosylceramide as a Potential Biomarker of Inflammatory Bowel Disease in Children

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1083
Author(s):  
Aleksandra Filimoniuk ◽  
Agnieszka Blachnio-Zabielska ◽  
Monika Imierska ◽  
Dariusz Marek Lebensztejn ◽  
Urszula Daniluk
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
High Performance ◽  
Area Under The Curve ◽  
Study Groups ◽  
Diagnostic Value ◽  
Serum Samples ◽  
Specificity And Sensitivity ◽  
Potential Biomarker ◽  
Inflammatory Bowel

An altered ceramide composition in patients with inflammatory bowel disease (IBD) has been reported recently. The aim of this study was to evaluate the concentrations of sphingolipids in the serum of treatment-naive children with newly diagnosed IBD and to determine the diagnostic value of the tested lipids in pediatric IBD. The concentrations of sphingolipids in serum samples were evaluated using a quantitative method, an ultra-high-performance liquid chromatography-tandem mass spectrometry in children with Crohn’s disease (CD) (n=34), ulcerative colitis (UC) (n = 39), and controls (Ctr) (n = 24). Among the study groups, the most significant differences in concentrations were noted for C16:0-LacCer, especially in children with CD compared to Ctr or even to UC. Additionally, the relevant increase in C20:0-Cer and C18:1-Cer concentrations were detected in both IBD groups compared to Ctr. The enhanced C24:0-Cer level was observed only in UC, while C18:0-Cer only in the CD group. The highest area under the curve (AUC), specificity, and sensitivity were determined for C16:0-LacCer in CD diagnosis. Our results suggest that the serum LacC16-Cer may be a potential biomarker that distinguishes children with IBD from healthy controls and differentiates IBD subtypes. In addition, C20:0-Cer and C18:0-Cer levels also seem to be closely connected with IBD.

scholarly journals Seropositivity to canine tick-borne pathogens in a population of sick dogs in Italy

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jairo Alfonso Mendoza-Roldan ◽  
Giovanni Benelli ◽  
Marcos Antonio Bezerra-Santos ◽  
Viet-Linh Nguyen ◽  
Giuseppe Conte ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Serological Test ◽  
Control Strategies ◽  
Central Italy ◽  
Rickettsia Conorii ◽  
High Seroprevalence ◽  
The South ◽  
Serum Samples ◽  
Serological Tests ◽  
Distribution Maps

Abstract Background Canine vector-borne diseases (CVBDs) associated to ticks are among the most important health issues affecting dogs. In Italy, Ehrlichia canis, Anaplasma spp., Rickettsia conorii and Borrelia burgdorferi (s.l.) have been studied in both healthy canine populations and those clinically ill with suspected CVBDs. However, little information is currently available on the overall prevalence and distribution of these pathogens in the country. The aim of this study was to assess the prevalence and distribution of tick-borne pathogens (TBPs) in clinically suspect dogs from three Italian macro areas during a 15-year period (2006–2020). Methods A large dataset (n = 21,992) of serological test results for selected TBPs in three macro areas in Italy was analysed using a Chi-square test to evaluate the associations between the categorical factors (i.e. macro area, region, year, sex and age) and a standard logistic regression model (significance set at P = 0.05). Serological data were presented as annual and cumulative prevalence, and distribution maps of cumulative positive cases for TBPs were generated. Results Of the tested serum samples, 86.9% originated from northern (43.9%) and central (43%) Italy. The majority of the tests was requested for the diagnosis of E. canis (47%; n = 10,334), followed by Rickettsia spp. (35.1%; n = 7725), B. burgdorferi (s.l.) (11.6%; n = 2560) and Anaplasma spp. (6.2%; n = 1373). The highest serological exposure was recorded for B. burgdorferi (s.l.) (83.5%), followed by Rickettsia spp. (64.9%), Anaplasma spp. (39.8%) and E. canis (28.7%). The highest number of cumulative cases of Borrelia burgdorferi (s.l.) was recorded in samples from Tuscany, central Italy. Rickettsia spp. was more prevalent in the south and on the islands, particularly in dogs on Sicily older than 6 years, whereas Anaplasma spp. was more prevalent in the north and E. canis more prevalent in the south and on the islands. Conclusions The results of this study highlight the high seroprevalence and wide distribution of the four TBPs in dogs with clinically suspected CVBDs from the studied regions of Italy. The very high seroprevalence of B. burgdorferi (s.l.) exemplifies a limitation of this study, given the use of clinically suspect dogs and the possibility of cross-reactions when using serological tests. The present research provides updated and illustrative information on the seroprevalence and distribution of four key TBPs, and advocates for integrative control strategies for their prevention. Grapic abstract

scholarly journals Antibodies anti-trypanosomatides in domestic cats in Paraná: who is at highest risk of infection?

2018 ◽  
Vol 27 (2) ◽  
pp. 232-236 ◽  
Author(s):  
Andressa Maria Rorato Nascimento de Matos ◽  
Eloiza Teles Caldart ◽  
Fernanda Pinto Ferreira ◽  
Keila Clarine Monteiro ◽  
Marielen de Souza ◽  
...  
Keyword(s):  
Antibody Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Domestic Cats ◽  
Serum Samples ◽  
Animal Group ◽  
Animal Protection ◽  
Leishmania Spp ◽  
In Series ◽  
Different Populations ◽  
Simple Logistic

Abstract The aim of this study were to detect antibodies anti-Leishmania spp. and anti-Trypanosoma cruzi in two different populations of domestic cats (Felis catus domesticus) from North Paraná referred for surgical castration and to determine which characteristics of the animals studied may be associated with seropositivity. Serum samples from 679 cats were analyzed using enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence antibody test (IFAT) in series. Associations between age, sex, race, year of care and animal group were verified using the simple logistic regression. Percentage of 8.5% (58/679) of cats were positive for Leishmania spp. and 7.6% (51/673) for T. cruzi by the tests ELISA and IFAT. Animals collected by non-governmental animal protection organizations presented more seropositivity for Leishmania spp. (p<0.0001). Results shown that Leishmania spp. and T. cruzi are present in domestic cats in the northern part of the state of Paraná, as well as, owners of non-governmental animal protection organizations may be more exposed to leishmaniasis when compared to other animal owners evaluated in the present study.

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

2020 ◽  
Author(s):  
RIn Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
Measurement System ◽  
False Positive ◽  
Laboratory Testing ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

scholarly journals Point-of-care serological assays for SARS-CoV-2 in a UK hospital population: potential for enhanced case finding

2020 ◽  
Author(s):  
Scott Pallett ◽  
Aatish Patel ◽  
Gary Davies ◽  
Luke Moore
Keyword(s):  
Test Performance ◽  
Serological Test ◽  
Point Of Care ◽  
Rapid Test ◽  
Antibody Test ◽  
Preliminary Evaluation ◽  
Hospital Inpatient ◽  
Case Identification ◽  
Global Pandemic ◽  
Population Potential

Abstract Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic, causing over 3,600,000 reported cases and 250,000 deaths worldwide.1 Case identification has predominantly been made by real-time polymerase chain reaction (PCR) during the acute phase and largely restricted to healthcare laboratories. Serological assays are emerging but independent validation is urgently required to assess their utility. Where a plurality of point-of-care (POC) SARS-CoV-2 antibody test kits have become available, we will therefore aim to evaluate a range of kits against the current available gold-standard diagnostic test of PCR in an initial, exploratory study. We will then proceed to carry out testing with 200 hospital inpatients using the OrientGene COVID-19 IgG/IgM Rapid Test Cassette against PCR in order to undergo a preliminary evaluation of POC serological test performance characteristics within a hospital inpatient cohort.

scholarly journals Assessment of the Field Utility of a Rapid Point-of-Care Test for SARS-CoV-2 Antibodies in a Household Cohort

2021 ◽  
Author(s):  
Mehal Churiwal ◽  
Kelly D. Lin ◽  
Salman Khan ◽  
Srijana Chhetri ◽  
Meredith S. Muller ◽  
...  
Keyword(s):  
Cohort Study ◽  
Confidence Interval ◽  
Point Of Care ◽  
Natural Infection ◽  
Field Performance ◽  
Antibody Test ◽  
Asymptomatic Infection ◽  
Point Of Care Test ◽  
Antibody Tests ◽  
Rapid Antibody

Point-of-care (POC) tests to detect SARS-CoV-2 antibodies offer quick assessment of serostatus after natural infection or vaccination. We compared the field performance of the BioMedomics COVID-19 IgM/IgG Rapid Antibody Test against an ELISA in 303 participants enrolled in a SARS-CoV-2 household cohort study. The rapid antibody test was easily implemented with consistent interpretation across 14 users in a variety of field settings. Compared with ELISA, detection of seroconversion lagged by 5 to 10 days. However, it retained a sensitivity of 90% (160/177, 95% confidence interval [CI] 85–94%) and specificity of 100% (43/43, 95% CI 92–100%) for those tested 3 to 5 weeks after symptom onset. Sensitivity was diminished among those with asymptomatic infection (74% [14/19], 95% CI 49–91%) and early in infection (45% [29/64], 95% CI 33–58%). When used appropriately, rapid antibody tests offer a convenient way to detect symptomatic infections during convalescence.

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