scholarly journals Epidemiological Study of Thogoto and Dhori Virus Infection in People Bitten by Ticks, and in Sheep, in an Area of Northern Spain

2020 ◽  
Vol 17 (7) ◽  
pp. 2254
Author(s):  
Lourdes Lledó ◽  
Consuelo Giménez-Pardo ◽  
María Isabel Gegúndez
Keyword(s):  
Virus Infection ◽  
Epidemiological Study ◽  
Human Subjects ◽  
Acute Infection ◽  
Immunofluorescence Assay ◽  
Northern Spain ◽  
Serum Samples ◽  
Igm Antibodies

There is little information on Thogoto virus (THOV) and Dhori virus (DHOV)infection in Spain. A total of 283 serum samples from 150 human subjects (78 males, 72 females) bitten by ticks, as well as samples from 120 sheep (one per animal), were studied by immunofluorescence assay. All human and animal subjects were from the province of Palencia in northern Spain. Eight human subjects had antibodies against THOV (seroprevalence: 5.3%) and six had antibodies against DHOV (seroprevalence: 4%); titers ranged between 1/32–1/256 and 1/32–1/128, respectively. No significant differences were seen in seroprevalence in terms of gender or age, although people with antibodies were significantly more likely to have had contact with livestock for professional reasons. One subject with an acute infection had IgM antibodies to both viruses and seroconverted to IgG. For the sheep, 24 serum samples were positive for antibodies to THOV (seroprevalence: 20%) and 32 for antibodies to DHOV (seroprevalence: 26.8%); titers ranged between 1/16 and 1/128. The seroprevalence of both viruses was significantly higher in animals < 4 years of age. Together, these results reveal the circulation of DHOV and THOV in humans and sheep in the province of Palencia. Sheep might be used as indicators of the presence of these organisms.

scholarly journals Significance of IgG avidity test in diagnosis of west Nile virus infection

2017 ◽  
Vol 70 (11-12) ◽  
pp. 395-401
Author(s):  
Ivana Hrnjakovic-Cvjetkovic ◽  
Jelena Radovanov ◽  
Gordana Kovacevic ◽  
Aleksandra Patic ◽  
Natasa Nikolic ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
Acute Infection ◽  
Late Phase ◽  
West Nile Virus Infection ◽  
Igg Antibodies ◽  
Serum Samples ◽  
West Nile ◽  
Igm Antibodies ◽  
Igg Avidity

Introduction. Serological tests appear to be the method of choice for establishing the diagnosis in the late phase of West Nile virus infection. Long persistence of IgM antibodies against West Nile virus is described and may be a problem for determination of the time of acquisition of West Nile virus infection. The aim of the study was to estimate the significance of IgG avidity determination in establishing the diagnosis of West Nile virus infection. Material and Methods. In a study 56 serum samples seropositive against West Nile virus were included. 24 serum samples were collected in 2012 from healthy residents of South-Backa district and 32 serum samples were collected in 2014 from 124 patients suspected of having West Nile virus infection. Commercial enzyme-linked immunosorbent tests were used for the detection of West Nile virus-specific IgM and IgG antibodies and IgG avidity. Results. Out of 124 patients suspected of having West Nile virus infection, 32 (25.8%) were seropositive for West Nile virus antibodies. Acute infection was laboratory confirmed in 15 (46.9%) cases. All patients with acute infection were West Nile virus IgM positive, 13 (85%) were West Nile virus IgG positive, and 2 (15%) had a borderline result for West Nile virus IgG antibodies. Out of 32 seropositive patients the presence of IgM antibodies was determined in 22 (68.7%). In a group of samples with high IgG avidity values, 6 were IgM positive, while 8 were IgM negative. Conclusion. West Nile virus IgM and IgG antibody serological assays alone are not sufficient for the accurate and reliable diagnosis of WNV infection. West Nile virus IgG avidity testing is necessary to ensure the differential diagnosis of acute from past West Nile virus infection.

scholarly journals Evaluation of SARS-CoV-2 Neutralizing Antibodies Using a Vesicular Stomatitis Virus Possessing SARS-CoV-2 Spike Protein

2020 ◽  
Author(s):  
Hideki Tani ◽  
Long Tan ◽  
Miyuki Kimura ◽  
Yoshihiro Yoshida ◽  
Hiroshi Yamada ◽  
...  
Keyword(s):  
Virus Infection ◽  
Whole Blood ◽  
Neutralizing Antibodies ◽  
High Specificity ◽  
Immunofluorescence Assay ◽  
Hospitalized Patients ◽  
Pseudotyped Virus ◽  
Serum Samples ◽  
Live Virus ◽  
Specificity And Sensitivity

Abstract Background:SARS-CoV-2 is a novel coronavirus that emerged in 2019 and is now classified in the genus Coronavirus with closely related SARS-CoV. SARS-CoV-2 is highly pathogenic in humans and is classified as a biosafety level (BSL)-3 pathogen, which makes manipulating it relatively difficult due to its infectious nature. Methods:To circumvent the need for BSL-3 laboratories, an alternative assay was developed that avoids live virus and instead uses a recombinant VSV expressing luciferase and possesses the full length or truncated spike proteins of SARS-CoV-2. Furthermore, to measure SARS-CoV-2 neutralizing antibodies under BSL2 conditions, a chemiluminescence reduction neutralization test (CRNT) for SARS-CoV-2 was developed. The neutralization values of the serum samples collected from hospitalized patients with COVID-19 or SARS-CoV-2 PCR-negative donors against the pseudotyped virus infection evaluated by the CRNT were compared with antibody titers determined from an immunofluorescence assay (IFA). Results:The CRNT, which used whole blood collected from hospitalized patients with COVID-19, was also examined. As a result, the inhibition of pseudotyped virus infection was specifically observed in both serum and whole blood and was also correlated with the results of the IFA. Conclusions:In conclusion, the CRNT for COVID-19 is a convenient assay system that can be performed in a BSL-2 laboratory with high specificity and sensitivity for evaluating the occurrence of neutralizing antibodies against SARS-CoV-2.

scholarly journals Comparative Accuracy of the InBios Scrub Typhus Detect IgM Rapid Test for the Detection of IgM Antibodies by Using Conventional Serology

2015 ◽  
Vol 22 (10) ◽  
pp. 1130-1132 ◽  
Author(s):  
Hugh W. F. Kingston ◽  
Stuart D. Blacksell ◽  
Ampai Tanganuchitcharnchai ◽  
Achara Laongnualpanich ◽  
Buddha Basnyat ◽  
...  
Keyword(s):  
Rapid Diagnostic Test ◽  
Scrub Typhus ◽  
Specific Antigen ◽  
Rapid Test ◽  
Febrile Illness ◽  
High Specificity ◽  
Immunofluorescence Assay ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Comparative Accuracy

ABSTRACTThis study investigated the comparative accuracy of a recombinant 56-kDa type-specific antigen-based rapid diagnostic test (RDT) for scrub typhus for the detection of IgM antibodies by using conventional serology in well-characterized serum samples from undifferentiated febrile illness patients. The RDT showed high specificity and promising comparative accuracy, with 82% sensitivity and 98% specificity for samples defined positive at an IgM indirect immunofluorescence assay positivity cutoff titer of ≥1:1,600 versus 92% and 95% at ≥1:6,400, respectively.

scholarly journals Diagnosis of Dengue Virus Infection by the Visual and Simple AuBioDOT Immunoglobulin M Capture System

2003 ◽  
Vol 10 (6) ◽  
pp. 1074-1077 ◽  
Author(s):  
Susana Vázquez ◽  
Gilda Lemos ◽  
Maritza Pupo ◽  
Oscar Ganzón ◽  
Daniel Palenzuela ◽  
...  
Keyword(s):  
Virus Infection ◽  
Dengue Virus ◽  
Immunoglobulin M ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Dengue Virus Infection ◽  
Capture Elisa ◽  
Igm Antibodies ◽  
Health Organization

ABSTRACT The Dengue IgM Capture ELISA (MAC-ELISA) is the immunoenzymatic system recommended by the Pan American Health Organization and the World Health Organization for the serological diagnosis of dengue virus infection due to its high sensitivity, ease of performance, and use of a single acute-phase serum sample. However, tests with this enzyme-linked immunosorbent assay (ELISA) system are time-consuming and require equipment for washing, incubation, and reading of the results. AuBioDOT is a multistep visual diagnostic immunoassay that uses technology based on the immunoglobulin M (IgM) capture ELISA principle. This system uses white polyethylene opaque plates as the solid phase, colloidal gold as the marker, and silver ion amplification. It does not require special equipment, it is totally manually operated, and it can be performed in less than 1 h. The sensitivity and specificity of AuBioDOT for the detection of anti-dengue virus IgM antibodies were studied with a panel of 336 serum samples (150 serum samples from patients with suspected or serologically confirmed dengue virus infection, 186 serum samples from healthy blood donors and patients without dengue virus infection). The results were compared with those obtained by the MAC-ELISA. A sensitivity of 97.7% and a specificity of 97.1% were obtained. The concordance of the two tests was 97.3%, with a kappa index of 0.94. The application of AuBioDOT for the detection of anti-dengue virus IgM antibodies is recommended as an alternative method for the diagnosis of dengue virus infection, both for clinical diagnosis and for seroepidemiological surveillance. The system is useful under field conditions and in laboratories and requires little equipment.

scholarly journals Evaluation of SARS-CoV-2 neutralizing antibodies using a vesicular stomatitis virus possessing SARS-CoV-2 spike protein

2020 ◽  
Author(s):  
Hideki Tani ◽  
Long Tan ◽  
Miyuki Kimura ◽  
Yoshihiro Yoshida ◽  
Hiroshi Yamada ◽  
...  
Keyword(s):  
Virus Infection ◽  
Whole Blood ◽  
Neutralizing Antibodies ◽  
High Specificity ◽  
Immunofluorescence Assay ◽  
Hospitalized Patients ◽  
Pseudotyped Virus ◽  
Serum Samples ◽  
Live Virus ◽  
Specificity And Sensitivity

AbstractSARS-CoV-2 is a novel coronavirus that emerged in 2019 and is now classified in the genus Coronavirus with closely related SARS-CoV. SARS-CoV-2 is highly pathogenic in humans and is classified as a biosafety level (BSL)-3 pathogen, which makes manipulating it relatively difficult due to its infectious nature. To circumvent the need for BSL-3 laboratories, an alternative assay was developed that avoids live virus and instead uses a recombinant VSV expressing luciferase and possesses the full length or truncated spike proteins of SARS-CoV-2. Furthermore, to measure SARS-CoV-2 neutralizing antibodies under BSL2 conditions, a chemiluminescence reduction neutralization test (CRNT) for SARS-CoV-2 was developed. The neutralization values of the serum samples collected from hospitalized patients with COVID-19 or SARS-CoV-2 PCR-negative donors against the pseudotyped virus infection evaluated by the CRNT were compared with antibody titers determined from an immunofluorescence assay (IFA). The CRNT, which used whole blood collected from hospitalized patients with COVID-19, was also examined. As a result, the inhibition of pseudotyped virus infection was specifically observed in both serum and whole blood and was also correlated with the results of the IFA. In conclusion, the CRNT for COVID-19 is a convenient assay system that can be performed in a BSL-2 laboratory with high specificity and sensitivity for evaluating the occurrence of neutralizing antibodies against SARS-CoV-2.

scholarly journals Immunoglobulin-like Domain of HsFcμR as a Capture Molecule for Detection of Crimean-Congo Hemorrhagic Fever Virus- and Zika Virus-Specific IgM Antibodies

2019 ◽  
Vol 65 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Anne Rackow ◽  
Christa Ehmen ◽  
Ronald von Possel ◽  
Raquel Medialdea-Carrera ◽  
David Brown ◽  
...  
Keyword(s):  
Zika Virus ◽  
Specific Binding ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Size Exclusion ◽  
Animal Origin ◽  
Serum Samples ◽  
Crimean Congo Hemorrhagic Fever ◽  
Hemorrhagic Fever Virus ◽  
Igm Antibodies

Abstract BACKGROUND The cellular surface molecule HsTOSO/FAIM3/HsFcμR has been identified as an IgM-specific Fc receptor expressed on lymphocytes. Here, we show that its extracellular immunoglobulin-like domain (HsFcμR-Igl) specifically binds to IgM/antigen immune complexes (ICs) and exploit this property for the development of novel detection systems for IgM antibodies directed against Crimean-Congo hemorrhagic fever virus (CCHFV) and Zika virus (ZIKV). METHODS His-tagged HsFcμR-Igl was expressed in Escherichia coli and purified by affinity chromatography, oxidative refolding, and size-exclusion chromatography. Specific binding of HsFcμR-Igl to IgM/antigen ICs was confirmed, and 2 prototypic ELISAs for the detection of anti-CCHFV and anti-ZIKV IgM antibodies were developed. Thereby, patient sera and virus-specific recombinant antigens directly labeled with horseradish peroxidase (HRP) were coincubated on HsFcμR-Igl-coated ELISA plates. Bound ICs were quantified by measuring turnover of a chromogenic HRP substrate. RESULTS Assay validation was performed using paired serum samples from 15 Kosovar patients with a PCR-confirmed CCHFV infection and 28 Brazilian patients with a PCR-confirmed ZIKV infection, along with a panel of a priori CCHFV/ZIKV-IgM-negative serum samples. Both ELISAs were highly reproducible. Sensitivity and specificity were comparable with or even exceeded in-house gold standard testing and commercial kits. Furthermore, latex beads coated with HsFcμR-Igl aggregated upon coincubation with an IgM-positive serum and HRP-labeled antigen but not with either component alone, revealing a potential for use of HsFcμR-Igl as a capture molecule in aggregation-based rapid tests. CONCLUSIONS Recombinant HsFcμR-Igl is a versatile capture molecule for IgM/antigen ICs of human and animal origin and can be applied for the development of both plate- and bead-based serological tests.

Serological and molecular studies on subclinical hepatitis E virus infection using periodic serum samples obtained from healthy individuals

2005 ◽  
Vol 76 (4) ◽  
pp. 526-533 ◽  
Author(s):  
Takehiro Mitsui ◽  
Yukie Tsukamoto ◽  
Shigeru Suzuki ◽  
Chikao Yamazaki ◽  
Kazuo Masuko ◽  
...  
Keyword(s):  
Virus Infection ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Molecular Studies

scholarly journals IL-6 Receptor Blockade Increases Circulating Adiponectin Levels in People with Obesity: An Explanatory Analysis

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 79
Author(s):  
Stephan Wueest ◽  
Eleonora Seelig ◽  
Katharina Timper ◽  
Mark P. Lyngbaek ◽  
Kristian Karstoft ◽  
...  
Keyword(s):  
Exercise Training ◽  
Human Subjects ◽  
Receptor Blockade ◽  
Model Assessment ◽  
Serum Samples ◽  
Double Blind ◽  
Double Blind Clinical Trial ◽  
Homeostatic Model Assessment ◽  
Obese Human

Human obesity is associated with decreased circulating adiponectin and elevated leptin levels. In vitro experiments and studies in high fat diet (HFD)-fed mice suggest that interleukin-6 (IL-6) may regulate adiponectin and leptin release from white adipose tissue (WAT). Herein, we aimed to investigate whether IL-6 receptor blockade affects the levels of circulating adiponectin and leptin in obese human individuals. To this end, serum samples collected during a multicenter, double-blind clinical trial were analyzed. In the latter study, obese human subjects with or without type 2 diabetes were randomly assigned to recurrent placebo or intravenous tocilizumab (an IL-6 receptor antibody) administration during a 12-week exercise training intervention. Twelve weeks of tocilizumab administration (in combination with exercise training) trend wise enhanced the decrease in circulating leptin levels (−2.7 ± 8.2% in the placebo vs. −20.6 ± 5.6% in tocilizumab, p = 0.08) and significantly enhanced the increase in circulating adiponectin (3.4 ± 3.7% in the placebo vs. 27.0 ± 6.6% in tocilizumab, p = 0.01). In addition, circulating adiponectin levels were negatively correlated with the homeostatic model assessment of insulin resistance (HOMA-IR), indicating that increased adiponectin levels positively affect insulin sensitivity in people with obesity. In conclusion, IL-6 receptor blockade increases circulating adiponectin levels in people with obesity.

scholarly journals Etiology, clinical characteristics and coinfection status of bronchiolitis in Suzhou

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiahong Tan ◽  
Jinfeng Wu ◽  
Wujun Jiang ◽  
Li Huang ◽  
Wei Ji ◽  
...  
Keyword(s):  
Virus Infection ◽  
Clinical Characteristics ◽  
Immunofluorescence Assay ◽  
Clinical Syndrome ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Immunofluorescence ◽  
Increased Risk ◽  
Syncytial Virus ◽  
Direct Immunofluorescence Assay ◽  
Mixed Virus Infection

Abstract Background Bronchiolitis is a clinical syndrome commonly encountered in practice, particularly among infants and young children. To investigate the prevalence of pathogens in hospitalized children with bronchiolitis and study the clinical characteristics of bronchiolitis with or without coinfections. Methods We investigated the respiratory specimens and clinical data of 1012 children with bronchiolitis who were treated at the Children’s Hospital of Soochow University between November 2011 and December 2018. The nasopharyngeal aspirates were examined to detect viruses by direct immunofluorescence assay or polymerase chain reaction (PCR). Mycoplasma pneumoniae (MP) was tested by PCR and enzyme-linked immunosorbent assay. Results Of the 1134 children less than 2 years with bronchiolitis, 122 were excluded by exclusion criteria. Causative pathogen was detected in 83.2% (842 of 1012). The majority of these (614 [72.9%] of 842) were single virus infection. The most common pathogens detected were respiratory syncytial virus (RSV) (44.4%), MP (15.6%), and human rhinovirus (HRV) (14.4%). Coinfection was identified in 13.5% (137 of 1012) of the patients. Coinfection included mixed virus infection and virus infection with MP infection. Children with single virus infection had a higher rate of oxygen therapy compared with single MP infection. Conclusions The most common pathogen detected in children with bronchiolitis is RSV, followed by MP and HRV. Coinfection leads to a longer period of illness, increased severity of the symptoms and increased risk of hypoxemia.

scholarly journals Utility of the Cobas® Plasma Separation Card as a Sample Collection Device for Serological and Virological Diagnosis of Hepatitis C Virus Infection

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 473
Author(s):  
Fernando Velásquez-Orozco ◽  
Ariadna Rando-Segura ◽  
Joan Martínez-Camprecios ◽  
Paula Salmeron ◽  
Adrián Najarro-Centeno ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Viral Load ◽  
Hepatitis C ◽  
Virus Infection ◽  
Hepatitis C Virus Infection ◽  
Sample Collection ◽  
Serum Samples ◽  
Plasma Separation ◽  
Virological Diagnosis ◽  
A Prospective Study

Diagnosis and clinical management of people infected with hepatitis C virus (HCV) relies on results from a combination of serological and virological tests. The aim of this study was to compare the performance of dried plasma spots (DPS), prepared using the cobas® Plasma Separation Card (PSC), to plasma and serum from venipuncture, for HCV diagnosis. We carried out a prospective study using DPS and paired plasma or serum samples. Serum and DPS samples were analyzed by immunoassay using Elecsys® Anti-HCV II (Roche). Plasma and DPS samples were analyzed using the cobas® HCV viral load and cobas® HCV genotyping tests (Roche). All DPS samples that had high anti-HCV antibody titers in serum were also antibody-positive, as were five of eight samples with moderate titers. Eight samples with low titers in serum were negative with DPS. Among 80 samples with plasma HCV viral loads between 61.5 and 2.2 × 108 IU/mL, 74 were RNA-positive in DPS. The mean viral load difference between plasma and DPS was 2.65 log10 IU/mL. The performance of DPS for detection of serological and virological markers of hepatitis C virus infection was comparable to that of the conventional specimen types. However, the limits of detection were higher for DPS.

Sign in / Sign up

Export Citation Format

Share Document