Validity of a Serological Diagnostic Kit for SARS-CoV-2 Available in Iran

2020 ◽  
Vol 23 (9) ◽  
pp. 629-632
Author(s):  
Hamid Reza Shamsollahi ◽  
Mostafa Amini ◽  
Shaban Alizadeh ◽  
Saharnaz Nedjat ◽  
Ali Akbari-Sari ◽  
...  
Keyword(s):  
Diagnostic Techniques ◽  
Effective Control ◽  
Molecular Technique ◽  
Size Estimation ◽  
Medical Sciences ◽  
Serological Tests ◽  
Standard Case ◽  
Epidemic Size ◽  
Low Sensitivity ◽  
Negative Controls

Background: The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic broke out in December 2019 and is now characterized as a pandemic. Effective control of this infectious disease requires access to diagnostic techniques, for both case finding and epidemic size estimation. The molecular technique is routinely used worldwide. Although it is the "standard" case detection and management method, it has its own shortcomings. Thus, some easy-to-use rapid serological tests have been developed. Methods: One hundred and fourteen positive RT-PCR-diagnosed patients were tested by VivaDiag Kit, a brand of rapid serological kits available in hospitals affiliated to Tehran University of Medical Sciences (TUMS), Tehran, Iran. Frozen serum specimens taken from healthy people in summer and fall 2019 were also tested as negative controls. Results: Test sensitivity was 47.9% (95% confidence interval [CI]: 38.8-56.9) for IgM and 47.0% (95% CI: 38.0–56.0) for IgG. There was no difference between IgG and IgM seropositivity except in one case. Specificity was calculated as 99.0% (95% CI: 96.4–99.9) for IgM and of 100.0% (95% CI: 0.98.2–100.0) for IgG. Sensitivity was higher in men and older participants. Conclusion: This test can be used for epidemiological investigations, especially for the estimation of the level of infection in the community, after it is properly corrected for sensitivity and specificity. The low sensitivity could be attributed to the technical limitations of the kit or low levels of antibodies after infection. The different sensitivity in age and sex groups supports the hypothesis that different people show different immune responses to this virus.

scholarly journals Assessment of a serological diagnostic kit of SARS-CoV-2 availble in Iran

2020 ◽  
Author(s):  
Hamid Reza Shamsollahi ◽  
Mostafa Amini ◽  
Shaban Alizadeh ◽  
Saharnaz Nedjat ◽  
Ali Akbari-Sari ◽  
...  
Keyword(s):  
Diagnostic Techniques ◽  
Effective Control ◽  
Molecular Technique ◽  
Size Estimation ◽  
Serological Tests ◽  
Standard Case ◽  
Technical Limitation ◽  
Epidemic Size ◽  
Low Sensitivity ◽  
Negative Controls

AbstractBackgroundThe SARS-CoV-2 epidemic broke out in December 2019 and now is characterized as a pandemic. The effective control of this infectious disease requires access to diagnostic techniques, both for case finding and epidemic size estimation. The molecular technique is routinely being used worldwide. Although it is the “standard” case detection and management method, it has its own shortcomings. Thus, some easy-to-use rapid serological tests were developed.MethodsOne hundred and fourteen positive RT-PCR-diagnosed patients were tested by VivaDiag Kit, a brand of rapid serological kits available in hospitals affiliated to Tehran University of Medical Sciences (TUMS), Tehran, Iran. Frozen serum specimens taken from healthy people in summer and autumn 2019, were also tested as negative controls.ResultsThe test sensitivity was 47.9% (95% confidence interval [CI]: 38.8-56.9) for IgM and 47.0% (95% CI: 38.0-56.0) for IgG. There was no difference between IgG and IgM seropositivity except in one case. Specificity was calculated as 99.0% (95% CI: 96.4-99.9) for IgM and of 100.0% (95% CI: 0.98.2-100.0) for IgG. Sensitivity was higher in men and older participants.ConclusionThis test can be used for epidemiological investigations especially for the estimation of the level of infection in the community, after it is properly corrected for sensitivity and specificity. The low sensitivity could be attributed to the technical limitation of the kits or low levels of antibodies after infection. The different sensitivity in age and sex groups supports the hypothesis that different people show different immune responses to this virus.

scholarly journals Serological Diagnosis of Paracoccidioidomycosis through a Western Blot Technique

2012 ◽  
Vol 19 (4) ◽  
pp. 616-619 ◽  
Author(s):  
M. C. Z. Perenha-Viana ◽  
I. A. A. Gonzales ◽  
S. R. Brockelt ◽  
L. N. C. Machado ◽  
T. I. E. Svidzinski
Keyword(s):  
Western Blot ◽  
Positive Reaction ◽  
Paracoccidioides Brasiliensis ◽  
Double Immunodiffusion ◽  
Serological Tests ◽  
Content Type ◽  
Mycological Examination ◽  
Low Sensitivity ◽  
Effective Diagnosis ◽  
Negative Controls

ABSTRACTParacoccidioidomycosis (PCM) is a serious infectious disease that progresses toward death if untreated. Its confirmatory diagnosis is made by the detection of the fungusParacoccidioides brasiliensisin a direct mycological examination or by histopathology. However, these techniques are of low sensitivity. Serological tests seem to be more promising. The objective of this study was to test Western blot (WB) analysis using sera from patients suspected of PCM to determine whether it represents a safe and sensitive serological technique for a rapid and effective diagnosis for this disease. Sera from 517 patients were analyzed through WB analysis and double-immunodiffusion (DID) techniques using a crude exoantigen ofP. brasiliensis339. DID gave positive reactions for 140 sera (27%) and WB for 250 sera (48.4%). All sera that had a positive reaction by DID also had a positive result with a 43-kDa glycoprotein by WB analysis. Among the 377 samples that were negative by DID, 29.1% were reactive in WB analysis. For the cutoff dilution used (1:400), a positive reaction was not observed with any of the 102 sera from patients with other diseases in regions where such diseases are endemic and 30 healthy individuals tested as negative controls. These results prove WB analysis to be a sensitive technique and suggest its inclusion among routine laboratory assays as a safe method for PCM diagnosis.

scholarly journals Diagnosis of tuberculosis in wildlife: a systematic review

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Jobin Thomas ◽  
Ana Balseiro ◽  
Christian Gortázar ◽  
María A. Risalde
Keyword(s):  
Systematic Review ◽  
Test Performance ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Diagnostic Techniques ◽  
Review Literature ◽  
Meat Industry ◽  
Post Mortem ◽  
Serological Tests ◽  
Ongoing Research

AbstractAnimal tuberculosis (TB) is a multi-host disease caused by members of the Mycobacterium tuberculosis complex (MTC). Due to its impact on economy, sanitary standards of milk and meat industry, public health and conservation, TB control is an actively ongoing research subject. Several wildlife species are involved in the maintenance and transmission of TB, so that new approaches to wildlife TB diagnosis have gained relevance in recent years. Diagnosis is a paramount step for screening, epidemiological investigation, as well as for ensuring the success of control strategies such as vaccination trials. This is the first review that systematically addresses data available for the diagnosis of TB in wildlife following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The article also gives an overview of the factors related to host, environment, sampling, and diagnostic techniques which can affect test performance. After three screenings, 124 articles were considered for systematic review. Literature indicates that post-mortem examination and culture are useful methods for disease surveillance, but immunological diagnostic tests based on cellular and humoral immune response detection are gaining importance in wildlife TB diagnosis. Among them, serological tests are especially useful in wildlife because they are relatively inexpensive and easy to perform, facilitate large-scale surveillance and can be used both ante- and post-mortem. Currently available studies assessed test performance mostly in cervids, European badgers, wild suids and wild bovids. Research to improve diagnostic tests for wildlife TB diagnosis is still needed in order to reach accurate, rapid and cost-effective diagnostic techniques adequate to a broad range of target species and consistent over space and time to allow proper disease monitoring.

scholarly journals Human and animal cystic echinococcosis in Tataouine governorate: hypoendemic area in a hyperendemic country, myth or reality?

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Selim M’rad ◽  
Raja Chaâbane-Banaoues ◽  
Massaouda Ghrab ◽  
Hamouda Babba ◽  
Myriam Oudni-M’rad
Keyword(s):  
Environmental Contamination ◽  
Cystic Echinococcosis ◽  
Mediterranean Area ◽  
Control Programme ◽  
Effective Control ◽  
Contamination Rate ◽  
Hydatid Cysts ◽  
African Countries ◽  
Serological Tests ◽  
Sera Samples

Abstract Background Cystic echinococcosis (CE) has a worldwide distribution and is especially prevalent in North African countries. With a mean annual surgical incidence (ASI) of CE of 12.7 per 100,000 inhabitants, Tunisia is one of the most CE endemic countries in the Mediterranean area. Tataouine governorate is considered to be the most CE hypoendemic region in Tunisia (ASI = 0.92) despite favourable socioeconomic conditions that enable maintenance of the Echinococcus granulosussensu lato (s.l.) life-cycle and a significant environmental contamination with E. granulosuss.l. eggs. The aim of this study was to assess human CE seroprevalence, prevalence of CE in food animals and environmental contamination by E. granulosus s.l. eggs in different districts of Tataouine governorate. Methods This study was conducted from January to December 2018. A total of 374 human sera samples were tested for the presence of immunoglobulin G antibodies against E. granulosus using a commercial ELISA kit. Specimens were also collected from animals slaughtered at the Tataouine abattoir (n = 8609) and examined for the presence of hydatid cysts; 111 hydatid cysts were genotyped. Eggs of E. granulosuss.l. were identified by PCR and DNA sequencing from dog faecal samples (n = 288). Results Serological tests showed that 8.5% of the sera samples tested were positive for E. granulosus-specific antibodies. The average prevalence of hydatidosis in livestock was 1.6%, and CE infection was more prevalent in cattle than in sheep, goats and dromedaries. The contamination rate of dog faeces by E. granulosus sensu stricto eggs varied significantly from 0 to 23.5% depending on the collection area. Molecular analyses only revealed the presence of the G1 genotype for cysts and eggs. Conclusions Based on our findings, CE is likely to be more endemic in the Tataouine governorate than previously described. Thus, to implement an effective control programme against CE, a national survey should be carried out to determine human CE prevalence in the different Tunisian governorates. Graphic Abstract

scholarly journals A High-Performance Multiplex Immunoassay for Serodiagnosis of Flavivirus-Associated Neurological Diseases in Horses

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Cécile Beck ◽  
Philippe Desprès ◽  
Sylvie Paulous ◽  
Jessica Vanhomwegen ◽  
Steeve Lowenski ◽  
...  
Keyword(s):  
High Performance ◽  
Neurological Diseases ◽  
Expression System ◽  
Cross Reactivity ◽  
Encephalitis Virus ◽  
Serological Tests ◽  
Multiplex Immunoassay ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus ◽  
Negative Controls

West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) are flaviviruses responsible for severe neuroinvasive infections in humans and horses. The confirmation of flavivirus infections is mostly based on rapid serological tests such as enzyme-linked immunosorbent assays (ELISAs). These tests suffer from poor specificity, mainly due to antigenic cross-reactivity among flavivirus members. Robust diagnosis therefore needs to be validated through virus neutralisation tests (VNTs) which are time-consuming and require BSL3 facilities. The flavivirus envelope (E) glycoprotein ectodomain is composed of three domains (D) named DI, DII, and DIII, with EDIII containing virus-specific epitopes. In order to improve the serological differentiation of flavivirus infections, the recombinant soluble ectodomain of WNV E (WNV.sE) and EDIIIs (rEDIIIs) of WNV, JEV, and TBEV were synthesised using theDrosophilaS2 expression system. Purified antigens were covalently bonded to fluorescent beads. The microspheres coupled to WNV.sE or rEDIIIs were assayed with about 300 equine immune sera from natural and experimental flavivirus infections and 172 nonimmune equine sera as negative controls. rEDIII-coupled microspheres captured specific antibodies against WNV, TBEV, or JEV in positive horse sera. This innovative multiplex immunoassay is a powerful alternative to ELISAs and VNTs for veterinary diagnosis of flavivirus-related diseases.

scholarly journals Systematic Review into Diagnostics for Post-Kala-Azar Dermal Leishmaniasis (PKDL)

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Emily R. Adams ◽  
Inge Versteeg ◽  
Mariska M. G. Leeflang
Keyword(s):  
Diagnostic Accuracy ◽  
Clinical Symptoms ◽  
Statistical Modelling ◽  
Study Quality ◽  
Serological Tests ◽  
Molecular Tests ◽  
Kala Azar ◽  
Valid Estimate ◽  
Low Sensitivity ◽  
Control Designs

Identification of post-kala-azar dermal leishmaniasis (PKDL) is important due to the long and toxic treatment and the fact that PKDL patients may serve as a reservoir for visceral leishmaniasis (VL). We summarized the published literature about the accuracy of diagnostic tests for PKDL. We searched Medline for eligible studies investigating the diagnostic accuracy of any test for PKDL. Study quality was assessed using QUADAS-2. Data were extracted from 21 articles including 43 separate studies. Twenty-seven studies evaluated serological tests (rK39 dipstick, ELISA, DAT, and leishmanin tests), six studies molecular tests, eight microscopy, and two cultures. Only a few of these studies reported a valid estimate of diagnostic accuracy, as most were case-control designs or used a reference standard with low sensitivity. The included studies were very heterogeneous, for example, due to a large variety of reference standards used. Hence, no summary estimates of sensitivity or specificity could be made. We recommend well-designed diagnostic accuracy trials that evaluate, side-by-side, all currently available diagnostics, including clinical symptoms, serological, antigen, molecular, and parasitological tests and possible use of statistical modelling to evaluate diagnostics when there is no suitable gold standard.

scholarly journals Diagnosis and Treatment Algorythm in Lyme Neuroborreliosis

2016 ◽  
Vol 62 (1) ◽  
pp. 121-127
Author(s):  
Brîndușa Țilea ◽  
Rodica Bălașa ◽  
Andrea Fodor ◽  
Țilea Ioan
Keyword(s):  
Borrelia Burgdorferi ◽  
Bacterial Species ◽  
Correct Diagnosis ◽  
Clinical Manifestations ◽  
Lyme Neuroborreliosis ◽  
Early Administration ◽  
Serological Tests ◽  
Initiation Of Therapy ◽  
Low Sensitivity ◽  
Third Generation Cephalosporins

AbstractLyme neuroborreliosis is an infection of the nervous system caused by spirochetes of the Borrelia burgdorferi sensulato group. Neurological clinical manifestations usually present a steady evolution and are different in patients from Europe compared to those from America, possibly due to vector agents and different bacterial species. Various diagnostic markers were studied in consideration of a clear or possible diagnosis of the disease, because evolution and complications depend on early diagnosis and initiation of therapy. The isolation of the bacterium is difficult, microscopic examination and the bacterial dezoxiribonucleic acid amplification shows low sensitivity. However, the diagnosis of Lyme neuroborreliosis is mainly based on serological methods that have a satisfactory sensitivity and specificity. A correct diagnosis can be performed by strictly respecting clinical guidelines and protocols and carefully interpreting the serological tests. The presence of anti-borrelia burgdorferi antibodies in the cerebrospinal fluid with evidence of intrathecal antibody production is the gold standard diagnosis of Lyme neuroborreliosis. Early administration of antibiotic treatment (third generation cephalosporins, cyclins, aminopenicillins) can produce the remission of neurological symptoms, the eradication of spirochetes in acute phase of the disease, thus avoiding the development of the chronic disease.

scholarly journals Application of Volatilome Analysis to the Diagnosis of Mycobacteria Infection in Livestock

2021 ◽  
Vol 8 ◽  
Author(s):  
Pablo Rodríguez-Hernández ◽  
Vicente Rodríguez-Estévez ◽  
Lourdes Arce ◽  
Jaime Gómez-Laguna
Keyword(s):  
Analytical Techniques ◽  
Diagnostic Techniques ◽  
Diagnostic Tools ◽  
Future Research ◽  
Control Programs ◽  
Targeted Analysis ◽  
Low Sensitivity ◽  
And Control

Volatile organic compounds (VOCs) are small molecular mass metabolites which compose the volatilome, whose analysis has been widely employed in different areas. This innovative approach has emerged in research as a diagnostic alternative to different diseases in human and veterinary medicine, which still present constraints regarding analytical and diagnostic sensitivity. Such is the case of the infection by mycobacteria responsible for tuberculosis and paratuberculosis in livestock. Although eradication and control programs have been partly managed with success in many countries worldwide, the often low sensitivity of the current diagnostic techniques against Mycobacterium bovis (as well as other mycobacteria from Mycobacterium tuberculosis complex) and Mycobacterium avium subsp. paratuberculosis together with other hurdles such as low mycobacteria loads in samples, a tedious process of microbiological culture, inhibition by many variables, or intermittent shedding of the mycobacteria highlight the importance of evaluating new techniques that open different options and complement the diagnostic paradigm. In this sense, volatilome analysis stands as a potential option because it fulfills part of the mycobacterial diagnosis requirements. The aim of the present review is to compile the information related to the diagnosis of tuberculosis and paratuberculosis in livestock through the analysis of VOCs by using different biological matrices. The analytical techniques used for the evaluation of VOCs are discussed focusing on the advantages and drawbacks offered compared with the routine diagnostic tools. In addition, the differences described in the literature among in vivo and in vitro assays, natural and experimental infections, and the use of specific VOCs (targeted analysis) and complete VOC pattern (non-targeted analysis) are highlighted. This review emphasizes how this methodology could be useful in the problematic diagnosis of tuberculosis and paratuberculosis in livestock and poses challenges to be addressed in future research.

scholarly journals Expression Levels of Candidate Circulating microRNAs in Early-Onset Neonatal Sepsis Compared With Healthy Newborns

2018 ◽  
Vol 11 ◽  
pp. 117863101879707 ◽  
Author(s):  
Benet B Dhas ◽  
Vijaya R Dirisala ◽  
B Vishnu Bhat
Keyword(s):  
Neonatal Sepsis ◽  
Inflammatory Responses ◽  
Diagnostic Techniques ◽  
Diagnostic Methods ◽  
Large Sample Size ◽  
Case Control Studies ◽  
Circulating Micrornas ◽  
Expression Levels ◽  
Sepsis Diagnosis ◽  
Low Sensitivity

The high mortality rate of neonatal sepsis is directly connected with time-consuming diagnostic methods that have low sensitivity and specificity. The need of the hour is to develop novel diagnostic techniques that are rapid and more specific. In this study, we estimated the expression levels of circulating microRNAs (miRNAs) that are involved in regulating immune response genes and underlying inflammatory responses, which may be used for sepsis diagnosis. The total circulating miRNA was isolated and the candidate miRNAs (miR-132, miR-146a, miR-155, and miR-223) were quantified by real-time polymerase chain reaction technique. Statistical analysis revealed that miR-132 ( P < .01) and miR-223 ( P < .05) were downregulated in septic newborns compared with healthy babies. The decrease in expression of miR-132 and miR-223 may be associated with increased expression of immune-related genes involved in TLR (Toll-like receptor) signaling pathway. Further case-control studies with large sample size are required to identify the potential of miRNAs in neonatal sepsis diagnosis.

scholarly journals Evaluation of broad-range 16S rRNA PCR for the diagnosis of bloodstream infections: two years of experience

2014 ◽  
Vol 8 (10) ◽  
pp. 1252-1258 ◽  
Author(s):  
Reem Mostafa Hassan ◽  
Mervat G El Enany ◽  
Hussien H Rizk
Keyword(s):  
Blood Culture ◽  
16S Rrna ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Bloodstream Infections ◽  
Molecular Techniques ◽  
Molecular Technique ◽  
High Negative Predictive Value ◽  
Patient Groups ◽  
Low Sensitivity

Introduction: Diagnosis of bloodstream infections using bacteriological cultures suffers from low sensitivity and reporting delay. Advanced molecular techniques introduced in many laboratories provide rapid results and may show improvements in patient outcomes. This study aimed to evaluate the usefulness of a molecular technique, broad-range 16S rRNA PCR followed by sequencing for the diagnosis of bloodstream infections, compared to blood culture in different patient groups. Methodology: Conventional PCR was performed, using broad-range 16S rRNA primers, on blood cultures collected from different patients with suspected bloodstream infections; results were compared with those of blood culture. Results: Though blood culture is regarded as the gold standard, PCR evaluation showed sensitivity of 86.25%, specificity of 91.25%, positive predictive value of 76.67%, negative predictive value of 95.22%, and accuracy of 88.8%. Conclusions: Molecular assays seem not to be sufficient to replace microbial cultures in the diagnosis of bloodstream infections, but they can offer a rapid, good negative test to rule out infection due to their high negative predictive value.

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