A filtration-based rapid test using a partially purified third-stage larval antigen to detect specific antibodies for the diagnosis of gnathostomiasis

2017 ◽  
Vol 93 (1) ◽  
pp. 26-32 ◽  
Author(s):  
A. Ma ◽  
Y. Wang ◽  
X.L. Liu ◽  
H.M. Zhang ◽  
P. Eamsobhana ◽  
...  
Keyword(s):  
Rapid Test ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Serological Tests ◽  
Promising Tool ◽  
Diagnostic Potential ◽  
Food Borne ◽  
Third Stage ◽  
Diagnostic Sensitivity And Specificity ◽  
Purified Antigen

AbstractHuman gnathostomiasis is an emerging food-borne parasitic disease caused by nematodes of the genusGnathostoma. Currently, serological tests are commonly applied to support clinical diagnosis. In the present study, a simple and rapid filtration-based test, dot immune–gold filtration assay (DIGFA) was developed using a partially purified antigen ofGnathostomathird-stage larvae (L3). A total of 180 serum samples were tested to evaluate the diagnostic potential of DIGFA for gnathostomiasis. The diagnostic sensitivity and specificity were 96.7% (29/30) and 100% (25/25), respectively. The cross-reactivity with sera from other helminthiasis patients ranged from 0 to 4%, with an average of 1.6% (2/125). DIGFA using a partially purified L3 antigen was not only simple and rapid, but also more accurate than standard assays for the diagnosis of human gnathostomiasis. DIGFA may represent a promising tool for application in laboratories or in the field, without requiring any instrumentation.

scholarly journals Evaluation of Rapid IgG4 Test for Diagnosis of Gnathostomiasis

2021 ◽  
Vol 59 (3) ◽  
pp. 257-263
Author(s):  
Yue Wang ◽  
An Ma ◽  
Xiao-Long Liu ◽  
Praphathip Eamsobhana ◽  
Xiao-Xian Gan
Keyword(s):  
Cross Reactivity ◽  
Therapeutic Effects ◽  
Parasitic Disease ◽  
Serum Samples ◽  
Promising Tool ◽  
Specific Igg4 ◽  
Third Stage ◽  
Human Sera ◽  
Practical Tool ◽  
Negative Controls

Human gnathostomiasis is a parasitic disease caused by Gnathostoma nematode infection. A rapid, reliable, and practical immunoassay, named dot immuno-gold filtration assay (DIGFA), was developed to supporting clinical diagnosis of gnathostomiasis. The practical tool detected anti-Gnathostoma-specific IgG4 in human serum using crude extract of third-stage larvae as antigen. The result of the test was shown by anti-human IgG4 monoclonal antibody conjugated colloidal gold. The sensitivity and specificity of the test were both 100% for detection in human sera from patients with gnathostomiasis (13/13) and from healthy negative controls (50/50), respectively. Cross-reactivity with heterogonous serum samples from patients with other helminthiases ranged from 0 (trichinosis, paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis) to 25.0% (sparganosis), with an average of 6.3% (7/112). Moreover, specific IgG4 antibodies diminished at 6 months after treatment. This study showed that DIGFA for the detection of specific IgG4 in human sera could be a promising tool for the diagnosis of gnathostomiasis and useful for evaluating therapeutic effects.

scholarly journals Peptide arrays incubated with three collections of human sera from patients infected with mosquito-borne viruses

F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 1875
Author(s):  
Maria del Pilar Martinez Viedma ◽  
Nurgun Kose ◽  
Leda Parham ◽  
Angel Balmaseda ◽  
Guillermina Kuan ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Cell Epitope ◽  
Cross Reactivity ◽  
Human Pathogens ◽  
Peptide Arrays ◽  
Serological Tests ◽  
Array Data ◽  
Prevalence Studies ◽  
Diagnostic Potential ◽  
Human Sera

Background: Global outbreaks caused by emerging or re-emerging arthropod-borne viruses (arboviruses) are becoming increasingly more common. These pathogens include the mosquito-borne viruses belonging to the Flavivirus and Alphavirus genera. These viruses often cause non-specific or asymptomatic infection, which can confound viral prevalence studies. In addition, many acute phase diagnostic tests rely on the detection of viral components such as RNA or antigen. Standard serological tests are often not reliable for diagnosis after seroconversion and convalescence due to cross-reactivity among flaviviruses. Methods: In order to contribute to development efforts for mosquito-borne serodiagnostics, we incubated 137 human sera on individual custom peptide arrays that consisted of over 866 unique peptides in quadruplicate. Our bioinformatics workflow to analyze these data incorporated machine learning, statistics, and B-cell epitope prediction. Results: Here we report the results of our peptide array data analysis, which revealed sets of peptides that have diagnostic potential for detecting past exposure to a subset of the tested human pathogens including Zika virus. These peptides were then confirmed using the well-established ELISA method. Conclusions: These array data, and the resulting peptides can be useful in diverse efforts including the development of new pan-flavivirus antibodies, more accurate epitope mapping, and vaccine development against these viral pathogens.

Serum Adsorption Study to Validate the Specificity of a Rapid Test to Detect Strongyloides stercoralis Infection

2021 ◽  
Author(s):  
Rahmah Noordin ◽  
Emelia Osman ◽  
Nor Suhada Anuar ◽  
Nor Mustaiqazah Juri ◽  
Anizah Rahumatullah ◽  
...  
Keyword(s):  
Small Sample Size ◽  
Rapid Test ◽  
High Specificity ◽  
Strongyloides Stercoralis ◽  
Cross Reactivity ◽  
Small Sample ◽  
Polystyrene Microspheres ◽  
Diagnostic Specificity ◽  
Serum Samples ◽  
Rapid Tests

A lateral flow rapid test for strongyloidiasis will greatly facilitate the control and elimination of the disease. Previously SsRapid™ prototype rapid test showed high diagnostic specificity to detect Strongyloides infection, determined using non-Strongyloides sera negative by IgG-ELISAs. Since high specificity is crucial before a test is used for public health control activities, further validation of its specificity is needed. Also, it needs to be ascertained whether non-Strongyloides sera positive by IgG-ELISAs and SsRapid are truly positive for Strongyloides or are cases of cross-reactivity. We performed 84 rapid tests (two types of dipsticks and cassettes) using 34 serum samples. They were divided into four groups based on Strongyloides infection and coinfection with other parasites and the availability of recombinant proteins and rapid tests for the latter. Sera was adsorbed using polystyrene microspheres beads separately coated with four recombinant parasite proteins. The small sample size is a limitation of this study; however, the overall results showed that the sera adsorption procedure was successful, and the SsRapid test is specific.

scholarly journals Evaluation of the Serologic Cross-Reactivity between Transmissible Gastroenteritis Coronavirus and Porcine Respiratory Coronavirus Using Commercial Blocking Enzyme-Linked Immunosorbent Assay Kits

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Ronaldo Magtoto ◽  
Korakrit Poonsuk ◽  
David Baum ◽  
Jianqiang Zhang ◽  
Qi Chen ◽  
...  
Keyword(s):  
Culture Medium ◽  
Large Deletion ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transmissible Gastroenteritis Virus ◽  
Serum Samples ◽  
Serological Tests ◽  
Transmissible Gastroenteritis ◽  
Respiratory Coronavirus ◽  
Porcine Respiratory

ABSTRACTThis study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n= 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with “suspect” results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated.IMPORTANCECurrent measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.

scholarly journals Short Communication: Evaluation of a New Rapid Diagnostic Test for Quality Assurance by Kala Azar Elimination Programme in Bangladesh

2011 ◽  
Vol 2011 ◽  
pp. 1-3 ◽  
Author(s):  
Md Gulam Musawwir Khan ◽  
Mohammad Shafiul Alam ◽  
Abu Toha Bhuiyan ◽  
Maleka Arjumand Jamil ◽  
Bijoy Saha ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Serological Test ◽  
Rapid Test ◽  
Test Strip ◽  
Cross Reactivity ◽  
Serological Tests ◽  
Kala Azar ◽  
Asymptomatic Patients ◽  
Elimination Programme ◽  
The Government

In Bangladesh, serological tests have been widely used for the primary screening of visceral leishmaniasis (VL). Several serologic tests are available for the diagnosis of VL. Selection of the best test is important to permit diagnostic differentiation between symptomatic and asymptomatic patients and to reduce cross-reactivity. We evaluated the effectiveness of a new serological test “Onsite Leishmania Ab Rapid Test” as a part of “quality assurance” activities for the kala azar elimination programme of the Government of Bangladesh. Plasma samples of 100 parasitologically confirmed cases of VL along with 101 healthy controls were tested, and “Onsite Leishmania Ab Rapid Test” strip tests were positive in 94 out of 100 confirmed VL cases, whereas four out of 51 healthy subjects from the VL endemic areas also tested positive. All the 50 healthy volunteers tested negative. Thus, the sensitivity and specificity of “Onsite Leishmania Ab Rapid Test” strip test were found to be 94% (95% CI: 87–98) and 96% (95% CI: 90–99), respectively. This study showed that the performance of the “Onsite Leishmania Ab Rapid Test” strip tests was up to the recommended level.

scholarly journals Evaluation of the performance of three serological tests for diagnosis of Leishmania infantum infection in dogs using latent class analysis

2020 ◽  
Vol 29 (4) ◽  
Author(s):  
Asier Basurco ◽  
Alda Natale ◽  
Katia Capello ◽  
Antonio Fernández ◽  
María Teresa Verde ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Leishmania Infantum ◽  
Latent Class ◽  
Rapid Test ◽  
Antibody Test ◽  
Latent Class Models ◽  
Canine Leishmaniasis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests

Abstract Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum. Serological methods are the most common diagnostic techniques used for the diagnosis of the CanL. The objective of our study was to estimate the sensitivity and specificity of one in-house ELISA kit (ELISA UNIZAR) and three commercially available serological tests (MEGACOR Diagnostik GmbH) including an immunochromatographic rapid test (FASTest LEISH®), an immunofluorescent antibody test (MegaFLUO LEISH®) and an enzyme-linked immunosorbent assay (MegaELISA LEISH®), using latent class models in a Bayesian analysis. Two hundred fifteen serum samples were included. The highest sensitivity was achieved for FASTest LEISH® (99.38%), ELISA UNIZAR (99.37%), MegaFLUO LEISH® (99.36%) followed by MegaELISA LEISH® (98.49%). The best specificity was obtained by FASTest LEISH® (98.43%), followed by ELISA UNIZAR (97.50%), whilst MegaFLUO LEISH® and MegaELISA LEISH® obtained the lower specificity (91.94% and 91.93%, respectively). The results of present study indicate that the immunochromatographic rapid test evaluated FASTest LEISH® show similar levels of sensitivity and specificity to the quantitative commercial tests. Among quantitative serological tests, sensitivity and specificity were similar considering ELISA or IFAT techniques.

scholarly journals Utility of rapid diagnostic kit tests for diagnosis of suspected dengue fever

2019 ◽  
Vol 7 (5) ◽  
pp. 1670
Author(s):  
Sarita Otta ◽  
Bichitrananda Swain
Keyword(s):  
Platelet Count ◽  
Dengue Fever ◽  
Rapid Test ◽  
Febrile Illness ◽  
Serum Samples ◽  
Serological Tests ◽  
Ns1 Antigen ◽  
Elisa Technique ◽  
Low Platelet Count ◽  
Sensitivity Specificity

Background: Dengue fever often presents as an undifferentiated febrile illness requiring a laboratory test for identification. Serological tests particularly on rapid kits for the detection of NS1Antigen, IgG and IgM antibodies are the most commonly performed test across the country.Methods: The serum samples of suspected dengue cases were tested by Rapid test kits for assessing all the three parameters as well as by ELISA for NS1 antigen test. The platelet count of the patients was obtained from automated coulter counter. The results thus obtained were analyzed in Excel format.Results: The serum samples from 304 suspected Dengue fever cases were received in the lab, of which 190 samples were positive either by rapid or ELISA and 176 when rapid card test was considered alone Highest seropositivity of dengue cases were observed in the age group of ≥60 years (79.2%) followed by 45-59 years (70.7%). On rapid test, 78 cases were NS1 antigen positive of which 60 cases were positive only for NS1 antigen. When NS1 rapid and ELISA tests when compared, 16 kit negative tests were positive on ELISA while 34 kit positive tests were ELISA negative.  Sensitivity, specificity, PPV and NPV when only NS1 was considered on rapid test kits when compared with ELISA were 78.9%, 87.8%, 63.8% and 93.8%. 33.5% of serologically positive cases of Dengue had low platelet count on admission while only among negative cases 17.2% had a low platelet.Conclusions: Rapid kits often show variable results thus needing a validation of them from end user. As a positive dengue test result is an essential prerequisite for diagnosis thus it is essential that for serological tests ELISA technique should be used for reporting. Thus, it also mandates more efforts at decentralization of NVBDCP to include both government and non government institutions.

scholarly journals Rapid Serological Tests for SARS-COV-2: Diagnostic Performance of Four Commercial Assays

2020 ◽  
Author(s):  
Sérgio Monteiro de Almeida ◽  
Regiane Nogueira Spalanzani ◽  
Meri Bordignon Nogueira ◽  
Beatriz Sanada Spiri ◽  
Barbara Maria Cavalli ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Rapid Test ◽  
Nucleic Acid Amplification ◽  
Control Group ◽  
Serum Samples ◽  
Serological Tests ◽  
Test Kit ◽  
Healthy Control ◽  
One Step ◽  
Substantial Heterogeneity

Abstract Background. This study aimed to assess the diagnostic performance of lateral flow immunochromatographic assays (LFA) of four different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG or total), comparing them with the nucleic acid amplification test (NAAT) or clinical defined (definite or probable SARS-CoV-2 infection respectively). Methods. 119 serum samples were randomly selected by convenience and distributed in the groups: (1) Group with SARS-CoV-2 infection [n=82; RT-qPCR positive (definite, n=70), and probable (n=12)]; (2) other diseases [n= 27; other viruses identified (n=8), SARS of other etiologies (n=19)]; (3) healthy control group (n=10). LFA essays of four manufacturers were compared: MedTest Coronavírus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and one Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co, China).Results. The four tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95%CI, 77.26-93.11%); specificity (100%; 90.51-100%); DOR (257; 60-1008); LR+ (33.43; 4.82-231.85); LR− (0.13; 0.08 - 0.23); accuracy (90.76%; 84.06- 95.29%); Matthews Correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR-) cases, all the kits studied showed limited values.Conclusion. Our data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the manufacturers. LFA tests cannot replace molecular diagnostics, but should be used as additional screening tool.

scholarly journals Peptide arrays of three collections of human sera from patients infected with mosquito-borne viruses

F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 1875
Author(s):  
Maria del Pilar Martinez Viedma ◽  
Nurgun Kose ◽  
Leda Parham ◽  
Angel Balmaseda ◽  
Guillermina Kuan ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Cell Epitope ◽  
Cross Reactivity ◽  
Human Pathogens ◽  
Peptide Arrays ◽  
Serological Tests ◽  
Array Data ◽  
Prevalence Studies ◽  
Diagnostic Potential ◽  
Human Sera

Background: Global outbreaks caused by emerging or re-emerging arthropod-borne viruses (arboviruses) are becoming increasingly more common. These pathogens include the mosquito-borne viruses belonging to the Flavivirus and Alphavirus genera. These viruses often cause non-specific or asymptomatic infection, which can confound viral prevalence studies. In addition, many acute phase diagnostic tests rely on the detection of viral components such as RNA or antigen. Standard serological tests are often not reliable for diagnosis after seroconversion and convalescence due to cross-reactivity among flaviviruses. Methods: In order to contribute to development efforts for mosquito-borne serodiagnostics, we incubated 137 human sera on individual custom peptide arrays that consisted of over 866 unique peptides in quadruplicate. Our bioinformatics workflow to analyze these data incorporated machine learning, statistics, and B-cell epitope prediction. Results: Here we report the results of our peptide array data analysis, which revealed sets of peptides that have diagnostic potential for detecting past exposure to a subset of the tested human pathogens including Zika virus. These peptides were then confirmed using the well-established ELISA method. Conclusions: These array data, and the resulting peptides can be useful in diverse efforts including the development of new pan-flavivirus antibodies, more accurate epitope mapping, and vaccine development against these viral pathogens.

scholarly journals Rapid Serological Tests for SARS-COV-2: Diagnostic Performance of Four Commercial Assays

2020 ◽  
Author(s):  
Sérgio Monteiro de Almeida ◽  
Regiane Nogueira Spalanzani ◽  
Meri Bordignon Nogueira ◽  
Beatriz Sanada Spiri ◽  
Barbara Maria Cavalli ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Rapid Test ◽  
Nucleic Acid Amplification ◽  
Control Group ◽  
Serum Samples ◽  
Serological Tests ◽  
Test Kit ◽  
Healthy Control ◽  
One Step ◽  
Substantial Heterogeneity

Abstract Background. This study aimed to assess the diagnostic performance of lateral flow immunochromatographic assays (LFA) of four different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG or total), comparing them with the nucleic acid amplification test (NAAT) or clinical defined (definite or probable SARS-CoV-2 infection respectively). Methods. 119 serum samples were randomly selected by convenience and distributed in the groups: (1) Group with SARS-CoV-2 infection [n=82; RT-qPCR positive (definite, n=70), and probable (n=12)]; (2) other diseases [n= 27; other viruses identified (n=8), SARS of other etiologies (n=19)]; (3) healthy control group (n=10). LFA essays of four manufacturers were compared: MedTest Coronavírus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and one Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co, China).Results. The four tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95%CI, 77.26-93.11%); specificity (100%; 90.51-100%); DOR (257; 60-1008); LR+ (33.43; 4.82-231.85); LR− (0.13; 0.08 - 0.23); accuracy (90.76%; 84.06- 95.29%); Matthews Correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR-) cases, all the kits studied showed limited values.Conclusion. Our data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the manufacturers. LFA tests cannot replace molecular diagnostics, but should be used as additional screening tool.

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