scholarly journals Seroprevalence of three emerging arboviral infections in Kuwaiti nationals

2021 ◽  
Vol 9 (3) ◽  
pp. 266-273
Author(s):  
A. S. Pacsa ◽  
U. C. Chaturvedi ◽  
A. S. Mustafa
Keyword(s):  
High Risk ◽  
Health Risk ◽  
Dengue Virus ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Major Health ◽  
Specific Antibodies ◽  
Igm Antibodies ◽  
Hanta Viruses

Diseases caused by dengue, s and fly fever and hanta viruses pose a major health risk in many countries. We determined the threat of these arboviral infections through a serologic using enzyme linked immunosorbent assay [ELISA] based tests. Hantavirus-specific antibodies were also detected using immunofluorescence. Of 499 samples tested for dengue virus IgG antibodies l4% were as positive for dengue positive by all the ELISA tests. Among the 42 showing strong IgG reactivity, only 1 was positive for dengue virus IgM antibodies. All samples tested for IgG antibodies to s and fly fever virus were negative. Hantavirus antibodies were detected in 11% of the 46 samples from high-risk individuals. The low prevalences suggest that at present these infections are not a serious problem in Kuwait

scholarly journals Double-Antigen Enzyme-Linked Immunosorbent Assay for Detection of Hepatitis E Virus-Specific Antibodies in Human or Swine Sera

2008 ◽  
Vol 15 (8) ◽  
pp. 1151-1157 ◽  
Author(s):  
Wei Ping Hu ◽  
Yang Lu ◽  
Nestor Amadeo Precioso ◽  
Hsiao Ying Chen ◽  
Teresa Howard ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Predictive Value ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Specific Antibodies ◽  
Kappa Value ◽  
Healthy Control ◽  
The Individual

ABSTRACT A new double-antigen sandwich-based enzyme-linked immunosorbent assay (ELISA) for the detection of total antibodies (immunoglobulin G [IgG] and IgM) specific for hepatitis E virus (HEV) was developed by utilizing well-characterized recombinant protein ET2.1 and its peroxidase-labeled counterpart. Our study showed that the ELISA detected all the positive patient samples (n = 265) regardless of whether they contained IgM or IgG antibodies, or both, while it maintained an excellent specificity of 98.8% with samples from various patient or healthy control groups (total number of samples, 424). The test had a detection limit for anti-HEV IgG antibodies that was equivalent to 62 mIU/ml of the international reference. Compared with the serological status of the specimens determined on the basis of tests performed at the individual collection sites, the testing outcome generated by the new ELISA had a good agreement of 99.3%, with a kappa value of 0.985. The positive predictive value and the negative predictive value for the new test reached 98.1% and 100%, respectively. This ELISA had a positive delta value of 4.836 and a negative delta value of 3.314 (where delta is a measure of the number of standard deviations by which the cutoff is separated from the mean of the sample groups) (N. Crofts, W. Maskill, and I. D. Gust, J. Virol. Methods 22:51-59, 1988), indicating that it had an excellent ability to differentiate the infected and noninfected cohorts. Furthermore, the new design enables the detection of antibodies not only in human samples but also in pig samples. Our preliminary data showed that the ELISA could detect seroconversion in samples from pigs at as early as 14 days postinoculation. The potential utility of detecting specific antibodies in pigs will be an added advantage for managing the disease, with suggested zoonotic implications.

scholarly journals Bayesian Validation of the Indirect Immunofluorescence Assay and Its Superiority to the Enzyme-Linked Immunosorbent Assay and the Complement Fixation Test for Detecting Antibodies against Coxiella burnetii in Goat Serum

2016 ◽  
Vol 23 (6) ◽  
pp. 507-514 ◽  
Author(s):  
Michael Muleme ◽  
John Stenos ◽  
Gemma Vincent ◽  
Angus Campbell ◽  
Stephen Graves ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Coxiella Burnetii ◽  
Indirect Immunofluorescence ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Immunofluorescence Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Content Type ◽  
Igm Antibodies

ABSTRACTAlthough many studies have reported the indirect immunofluorescence assay (IFA) to be more sensitive in detection of antibodies toCoxiella burnetiithan the complement fixation test (CFT), the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the assay have not been previously established for use in ruminants. This study aimed to validate the IFA by describing the optimization, selection of cutoff titers, repeatability, and reliability as well as the DSe and DSp of the assay. Bayesian latent class analysis was used to estimate diagnostic specifications in comparison with the CFT and the enzyme-linked immunosorbent assay (ELISA). The optimal cutoff dilution for screening for IgG and IgM antibodies in goat serum using the IFA was estimated to be 1:160. The IFA had good repeatability (>96.9% for IgG, >78.0% for IgM), and there was almost perfect agreement (Cohen's kappa > 0.80 for IgG) between the readings reported by two technicians for samples tested for IgG antibodies. The IFA had a higher DSe (94.8%; 95% confidence interval [CI], 80.3, 99.6) for the detection of IgG antibodies againstC. burnetiithan the ELISA (70.1%; 95% CI, 52.7, 91.0) and the CFT (29.8%; 95% CI, 17.0, 44.8). All three tests were highly specific for goat IgG antibodies. The IFA also had a higher DSe (88.8%; 95% CI, 58.2, 99.5) for detection of IgM antibodies than the ELISA (71.7%; 95% CI, 46.3, 92.8). These results underscore the better suitability of the IFA than of the CFT and ELISA for detection of IgG and IgM antibodies in goat serum and possibly in serum from other ruminants.

scholarly journals AB0663 COMPARING METHODS FOR DETERMINING ANTIBODIES TO SARS-CoV-2 USING A RAPID TEST AND ENZYME-LINKED IMMUNOSORBENT ASSAY

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1363.3-1364
Author(s):  
G. Gridneva ◽  
E. Aronova ◽  
S. Glukhova ◽  
M. Cherkasova ◽  
B. Belov ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
False Negative ◽  
Connective Tissue Diseases ◽  
Rapid Test ◽  
Test Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Igm Antibodies ◽  
History Of

Background:An accessible and sensitive and sensitive method for determining antibodies to a new coronavirus infection is often the key to timely provision of the necessary medical care to patients with rheumatic diseasesObjectives:Compare methods for determining antibodies to SARS-CoV-2 using a rapid test and enzyme-linked immunosorbent assay (ELISA)Methods:Methods for determining antibodies to SARS-CoV-2 using an express test (Chromatographic express test SARS-CoV-2 IgG / IgM (Xiamen Biotime Biotechnology, China)) and by ELISA (Reagent kit for enzyme immunoassay of class G immunoglobulins and class M to SARS-CoV-2 (Vector-Best, Russia)) were compared.80 patients were included with a diagnosis of rheumatoid arthritis 26 (33%), psoriatic arthritis - 9 (11%), osteoarthritis - 15 (19%), rheumatic heart disease 1 (1%), SLE 2 (3%), deramtomyositis 3 (4%), systemic sclerosis 5 (6%), systemic connective tissue diseases 4 (5%), including Sjogren’s syndrome, spondyloarthritis 15 (19%).17 (21%) denied a history of COVID-19 symptoms. 63 (79%) noted any signs of COVID-19 3.095 ± 1.45 months before the test (Median 3 [2; 4] months). 63 (79%) noted any signs of COVID-19 109 ± 43 days before the test (Median 111 [78; 135] months). The ELISA method was considered the standard.Results:When comparing the results of the express test and the determination of IgG antibodies to SARS-CoV-2 in serum, the following was obtained: the sensitivity of the express test is 99%. When comparing the results of the express test and the determination of IgM antibodies to SARS-CoV-2 in serum, it was obtained: among 66 samples with a negative result by the express test method, IgM was detected in 6 cases by ELISA/ So, 7.5% of 80 samples were false negative. In 3 of 14 samples with a positive result by the express test, IgM by ELISA was not detected. So, 3.75% of 80 samples were false-positive. (Table 1). When comparing the results of the IgM express test and ELISA, the following was obtained: the sensitivity of the express test was 33%, the specificity was 85%.Table 1.Antibodies, express-testAntibodies (ELISA), absentAntibodies (ELISA), presentRowTotalsIgGabsent011Row %0.00%100.00%present37679Row %3.80%96.20%Totals37780IgМabsent60666Row %90.91%9.09%present11314Row %78.57%21.43%Totals71980Conclusion:When comparing the results of the express test and the determination of IgG antibodies to SARS-CoV-2 in serum, the sensitivity of the express test is 99%. Determination of IgM antibodies to SARS-CoV-2 using a rapid test is less reliable than determination using ELISA.Disclosure of Interests:None declared.

Quantitative measurement of anti-aquaporin-4 antibodies by enzyme-linked immunosorbent assay using purified recombinant human aquaporin-4

2011 ◽  
Vol 18 (5) ◽  
pp. 578-586 ◽  
Author(s):  
Woojun Kim ◽  
Ji-Eun Lee ◽  
Xue Feng Li ◽  
Su-Hyun Kim ◽  
Byeong-Gu Han ◽  
...  
Keyword(s):  
High Risk ◽  
Disease Activity ◽  
Immunosorbent Assay ◽  
Neurological Diseases ◽  
Aquaporin 4 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Marker ◽  
Longitudinal Measurement ◽  
Longitudinal Measurements ◽  
Baculovirus System

Background: Antibodies to aquaporin-4 (AQP4-Ab), known as NMO-IgG, are a sensitive and specific marker for neuromyelitis optica (NMO). Methods: To develop an enzyme-linked immunosorbent assay (ELISA) for AQP4-Ab, we expressed M23 isoform of human AQP4 in a baculovirus system, and used it as an antigen. We measured AQP4-Ab in the sera of 300 individuals: 64 with definite NMO, 31 with high-risk NMO, 105 with multiple sclerosis (MS), 57 with other neurological diseases (ONDs), and 43 healthy controls. We also performed longitudinal measurements of AQP4–Ab in 787 samples collected from 51 patients with definite or high-risk NMO. Results: AQP4-Abs were positive in 72% with definite NMO, 55% with high-risk NMO, and 4% with MS, but none of the OND patients and the healthy individuals. The longitudinal measurement showed AQP4-Ab levels correlating with disease activity. Out of 38 initially seropositive patients, 21 became seronegative under effective immunosuppressive therapy. During most relapses, the serum AQP4-Ab levels were either high or rising compared with the previous value, although rising AQP4-Ab levels did not always lead to acute exacerbation. Two of the 13 initially seronegative patients converted to seropositive following acute exacerbations. Conclusions: We established an AQP4-Ab ELISA, which could be a potential monitoring tool of disease activity.

scholarly journals Development and Validation of 13-plex Luminex-Based Assay for Measuring Human Serum Antibodies to Streptococcus pneumoniae Capsular Polysaccharides

mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. e00128-18 ◽  
Author(s):  
Danka Pavliakova ◽  
Peter C. Giardina ◽  
Soraya Moghazeh ◽  
Shite Sebastian ◽  
Maya Koster ◽  
...  
Keyword(s):  
Human Serum ◽  
Lower Limit ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Correlate Of Protection ◽  
Immune Correlate ◽  
Relative Standard ◽  
Limit Of Quantitation

ABSTRACT A Luminex-based direct immunoassay (dLIA) platform has been developed to replace the standardized pneumococcal enzyme-linked immunosorbent assay platform. The multiplex dLIA simultaneously measures the concentration of serum immunoglobulin G (IgG) antibodies specific for pneumococcal capsular polysaccharide (PnPS) serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F. The assay uses poly-l-lysine (PLL)-conjugated PnPS, chemically coupled to spectrally distinct Luminex microspheres. Assay validation experiments were performed using residual human serum samples obtained from 13-valent pneumococcal conjugate vaccine (13vPnC) clinical studies. Assay results are expressed as IgG antibody concentrations in micrograms per milliliter using the international reference serum, 007sp. The lower limit of quantitation (LLOQ) for all serotypes covered in the 13-plex dLIA fell within the range of 0.002 to 0.038 µg/ml serum IgG. The difference between the lower limit and upper limit of the assay range was >500-fold for all serotypes, and assay variability was <20% relative standard deviation (RSD) for all serotypes. IgG antibody measurements were shown to be serotype-specific (some cross-reactivity was observed only between the structurally related serotypes 6A and 6B as well as 19A and 19F), and no interference was observed between the serotypes when the assay was performed in the 13-plex format compared to the singleplex assays. The 13-plex dLIA platform developed by Pfizer Inc. generates up to 143 test results in a single 96-well plate and is a suitable replacement of the enzyme-linked immunosorbent assay (ELISA) platform for evaluating vaccine clinical trials. IMPORTANCE The pneumococcal enzyme-linked immunosorbent assay (ELISA) measures IgG antibodies in human serum, and it is an important assay that supports licensure of pneumococcal vaccines. The immune correlate of protection, 0.35 µg/ml of IgG antibodies, was determined by the ELISA method. Pfizer has developed a new Luminex-based assay platform to replace the ELISA. These papers describe the important work of (i) validating the Luminex-based assay and (ii) bridging the immune correlate of protection (0.35 µg/ml IgG) to equivalent values reported by the Luminex platform.

Measles antibodies and response to vaccination in children aged less than 14 months: implications for age of vaccination

2011 ◽  
Vol 140 (9) ◽  
pp. 1599-1606 ◽  
Author(s):  
E. BORRÀS ◽  
L. URBIZTONDO ◽  
J. COSTA ◽  
J. BATALLA ◽  
N. TORNER ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Maternal Antibodies ◽  
Passive Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Blood Samples ◽  
Measles Outbreak ◽  
Measles Antibodies ◽  
Measles Vaccination

SUMMARYPassive immunity against measles decreases during the first months of life. The objective of this study was to determine titres of measles antibodies in children aged 9–14 months and their mothers before vaccination, and the children's response to vaccination. Blood samples were collected by capillary puncture before and 28 days after vaccination. Samples were obtained between February and June 2007 during an ongoing measles outbreak. Titres of specific measles IgG antibodies were determined by enzyme-linked immunosorbent assay. Seroconversion was defined as the presence of antibodies after vaccination in subjects without antibodies before vaccination. Maternal antibodies were present in 37·7% of all 69 children included and in 45·1% of children aged 9 months. Of the 51 children in whom a second sample was obtained, 31 (60·8%) were seronegative before vaccination and 61·3% seroconverted. Interference of maternal antibodies was 30%. Advancing the first dose of measles vaccination from 15 to 12 months is a correct strategy, given the increase in the time of susceptibility of infants to measles.

scholarly journals Epidemiological Survey and Screening Strategy for Dengue Virus in Blood Donors from Yunnan Province

2020 ◽  
Author(s):  
LING LI ◽  
YING LI ◽  
Shaofang Lu ◽  
Jing Dong ◽  
Haixia Xu ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Prevalence Rate ◽  
Screening Strategy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Igm Antibodies ◽  
Blood Center ◽  
Nonstructural Protein 1 ◽  
Elisa Testing

Abstract BACKGROUND Dengue virus (DENV) can be transmitted through blood transfusion. DENV was not screened regularly in Xishuangbanna Blood Center. This study was conducted in Xishuangbanna Blood Center with an attempt to develop DENV screening strategies in one of China’s high-incidence areas.METHODS Blood samples were collected randomly between June 2019 and August 2019. These samples were first screened for dengue IgG and IgM antibodies using enzyme-linked immunosorbent assay (ELISA). All reactive samples and some randomly-chosen non-reactive samples were used to detect DENV RNAs using real time polymerase-chain-reaction (RT-PCR) assay. After RT-PCR assay, these samples were further tested for soluble nonstructural protein 1 (NS1) using colloidal gold method. The demographic data of DENV positive donors were collected.RESULTS A total of 2,254 donor samples were collected and tested for dengue IgG and IgM antibodies by ELISA between June 2019 and August 2019. ELISA testing revealed that 598 donor samples were anti-IgG and/or anti-IgM reactive, with a serological prevalence rate of 26.53%. Among all the donor samples, 26 were RT-PCR positive and/or NS1 positive. Moreover, there were significant differences in the prevalence rate of DENV in terms of occupation (P=0.001), education(P<0.001) and ethnicity (P=0.026). CONCLUSION The prevalence of DENV in Xishuangbanna Blood Center was higher than most other blood centers that have implemented DENV donor screening. Our study provides the first-hand data about the prevalence of DENV and allows development of a screening strategy for clinical use.

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