scholarly journals Diagnosis of Norwalk Virus Infection by Indirect Enzyme Immunoassay Detection of Salivary Antibodies to Recombinant Norwalk Virus Antigen

2004 ◽  
Vol 11 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Christine L. Moe ◽  
Arnie Sair ◽  
Lisa Lindesmith ◽  
Mary K. Estes ◽  
Lee-Ann Jaykus
Keyword(s):  
Enzyme Immunoassay ◽  
Fold Increase ◽  
Virus Antigen ◽  
Attractive Alternative ◽  
Norwalk Virus ◽  
Serum Samples ◽  
Salivary Iga ◽  
Mucosal Antibody ◽  
Antibody Assays ◽  
Stool Samples

ABSTRACT Simple diagnostic tests are needed for the detection of norovirus (NoV) outbreaks. Salivary antibody assays provide an attractive alternative to collecting and testing serum or stool samples. Antibodies to Norwalk virus (NV) in oral fluid samples were compared with NV antibodies in serum collected from 38 volunteers challenged with NV inoculum. Pre- and postchallenge (day 4, 8, 14, and 21) saliva and serum samples were examined by enzyme immunoassay (EIA) using recombinant NV antigen. Of 18 infected subjects (those who shed NV in stool or who demonstrated immunoglobulin G [IgG] seroconversion), 15 (83%) had ≥4-fold increases in NV-specific salivary IgA and 15 (83%) had ≥4-fold increases in NV-specific salivary IgG when prechallenge and postchallenge saliva samples were compared. When the results of the IgA and IgG assays were combined, all 18 infected subjects showed ≥4-fold increases in NV-specific salivary IgG or IgA postchallenge titers compared to their prechallenge titers. One of 19 uninfected subjects had a ≥4-fold increase in NV-specific salivary IgG. The sensitivity of the combined assay results was 100%, and the specificity was 95%. NV-specific salivary IgA titers peaked around 14 days postchallenge. NV-specific salivary IgG and serum IgG titers continued to rise through 21 days postchallenge. The application of this EIA to an elementary school outbreak indicated that 67% of the subjects with confirmed infections had >4-fold rises in anti-NoV IgA when an antigen in the same genetic cluster as the outbreak virus was used. This is the first documented mucosal antibody response to NoV in children. This EIA provides a useful approach for diagnosing NoV outbreaks.

scholarly journals Characteristics of acute diarrhea adult cases with samples positive for Norwalk virus

2019 ◽  
Vol 9 (2) ◽  
pp. 375-380
Author(s):  
E. A. Kozhukhova ◽  
I. V. Gorbova
Keyword(s):  
Acute Diarrhea ◽  
Laboratory Data ◽  
Fold Increase ◽  
Enteric Pathogens ◽  
Adult Patients ◽  
Clinical Samples ◽  
Enteric Infection ◽  
Norwalk Virus ◽  
Serum Samples ◽  
Salmonella Spp

Remaining unmanageable,Norwalkvirus infection is clearly tended to be recorded at higher rate, including adult patients. In many cases, clinical picture of adult acute diarrhea in patients positive for Norwalk virus in clinical samples vs. pathogenetically-caused norovirus infection differs, thereby justifying comparison of clinical and laboratory data. A cohort retrospective study with 146 hospitalized adult patients suffering from acute moderate diarrhea positive for fecalNorwalkvirus was performed. Along with standard laboratory tests (culturing, serologic for detecting 4-fold increase in titer between paired serum samples, ELISA), detection of diarrhea-linked agents included PCR kit Amplisens® AII-bacto-screen-FL Lab (Interlabservice). The data obtained demonstrated that in adult patients with acute diarrhea 54.1% of cases were positive forNorwalkvirus as well as for other enteric pathogens, including bacteria found in 36.3% of cases. Moreover, clinical samples of patients with acute diarrhea hospitalized at least on day 4 vs. day 3 after the onset were significantly more often (by 1.5-fold) positive for association between Norwalk virus and other acute enteric infection agents mainly due to astrovirus (р = 0.03; PCR data) and Shigella spp. (culture-based and serologic methods; р = 0.03). In addition,Norwalkvirus was associated with rotavirus, but not other enteric pathogens, at 2.1-fold higher rate in clinical samples from patients treated vs. untreated with antimicrobials before hospitalization. Finally, clinical samples positive for Norwalk virus from patients with vs. without developed colitis syndrome were at higher risk of developing virus-bacterial enteric infection detecting Salmonella spp. at 7.6and 3-fold higher rate verified by culture-based and PCR assay, respectively. Importantly, patients with vs. without hemorrhagic colitis Salmonella spp. verified primarily a culture-based method was detected by 11-fold more frequently (p = 0.01). 

scholarly journals Screening of blood serum for markers of infection with measles, rubella, cytomegalovirus and Dengue Fever in Russian tourists

2014 ◽  
Vol 19 (6) ◽  
pp. 16-20
Author(s):  
S. A Pyankov ◽  
E. V Ivanova ◽  
V. A Ternovoy ◽  
A. P Agafonov
Keyword(s):  
Dengue Virus ◽  
Southeast Asia ◽  
Enzyme Immunoassay ◽  
Dengue Fever ◽  
Rubella Virus ◽  
Measles Virus ◽  
Virus Antigen ◽  
Unknown Etiology ◽  
Specific Class ◽  
Serum Samples

The aim of the study was in the differential specific diagnosis of viral infections of unknown etiology in patients who have recently returned from a trip to the countries of Southeast Asia and India. In 2013, SRC VB "Vector" examined single serum samples from 131 patients with suspected Dengue Fever. Dengue viral RNA was detected by means of polymerase chain reaction, NS dengue virus antigen and antibody classes M and G to Dengue virus - with the use of immunochromatographic methods and enzyme immunoassay. In the same sera the presence of specific IgM to measles, rubella and cytomegalovirus virus antigen was revealed by enzyme immunoassay and enzyme-enhanced chemiluminescence. As a result of examination 87 (66.4%) ofsamples were diagnosed as "Dengue fever". In seven out of the 87 samples there were detected specific class-M antibodies to cytomegalovirus. 44 sera (33.6%) out of 131 did not contain markers for Dengue fever. But 4 out of them contained IgM to measles virus, the other 5 sera contained IgM to rubella virus. Regional Centre of WHO laboratory confirmed three cases of measles, the one positive result for the content of IgM to rubella virus antigens results was interpreted as "equivalent." Identified in 2013 cases of importation ofmeasles and rubella by tourists from Southeast Asia and India have not resulted in the transmission of the disease through contact with others persons in Russia. In seven detected Dengue Fever cases opportunistic cytomegalovirus infection was revealed.

scholarly journals Detection of Norwalk Virus and Other Genogroup 1 Human Caliciviruses by a Monoclonal Antibody, RecombinantAntigen-Based Immunoglobulin M Capture Enzyme Immunoassay

1998 ◽  
Vol 36 (4) ◽  
pp. 1064-1069 ◽  
Author(s):  
James P. Brinker ◽  
Neil R. Blacklow ◽  
Mary K. Estes ◽  
Christine L. Moe ◽  
Kellogg J. Schwab ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Enzyme Immunoassay ◽  
Acute Phase ◽  
Recombinant Antigen ◽  
Immunoglobulin M ◽  
Norwalk Virus ◽  
Healthy Individuals ◽  
Test Specificity ◽  
Stool Samples ◽  
Adult Volunteers

Sera obtained from two groups of adult volunteers infected with Norwalk virus (NV) and two groups of patients involved in two natural outbreaks were tested for NV-reactive immunoglobulin M (IgM) by use of a monoclonal antibody, recombinant-antigen-based IgM capture enzyme immunoassay (EIA). No NV-reactive IgM was detected in the preinoculation sera of 15 volunteers, and 14 of 15 showed NV-reactive antibodies postinfection with NV. All of the volunteers showed IgG seroconversion to NV. In the outbreak studies, all 9 persons in one outbreak and 19 of 24 in another outbreak had NV-reactive IgM. In the first outbreak, only three of nine seroconverted to NV, which was likely due to late collection of acute-phase sera. In the second outbreak, 21 of 24 showed IgG seroconversion to NV. Sequencing of viruses isolated from five stool samples selected from those in the second outbreak showed that they were human calicivirus (HuCV) genogroup 1 viruses related, but not identical, to NV. In the volunteer studies, NV-reactive IgM was first detected 8 days postinoculation. The time of development of NV-reactive IgM antibodies in natural outbreaks was estimated to be similar to that found in the volunteer studies. Sera from three Hawaii virus-infected volunteers, four Snow Mountain virus patients, and 80 healthy individuals were negative for NV-reactive IgM, indicating test specificity for HuCV genogroup I infections. This capture IgM EIA is suitable for diagnosis of NV and other HuCV genogroup I infections and is especially useful when sera and fecal samples have not been collected early in the course of an outbreak.

scholarly journals Cellular and Humoral Immunity following Snow Mountain Virus Challenge

2005 ◽  
Vol 79 (5) ◽  
pp. 2900-2909 ◽  
Author(s):  
Lisa Lindesmith ◽  
Christine Moe ◽  
Jacques LePendu ◽  
Jeffrey A. Frelinger ◽  
John Treanor ◽  
...  
Keyword(s):  
Immune Response ◽  
Fold Increase ◽  
Norwalk Virus ◽  
Activated T Cells ◽  
Peripheral Blood Mononuclear ◽  
Salivary Iga ◽  
Virus Challenge ◽  
Humoral Immune ◽  
Serum Igg ◽  
Ifn Γ

ABSTRACT Little is known about the immune response to noroviruses. To elucidate the immunobiology of norovirus infection in humans, 15 volunteers were challenged with Snow Mountain virus (SMV), a genogroup 2 norovirus. We assessed the cellular and humoral immune response and infection by analyzing stool, serum, saliva, and peripheral blood mononuclear cell (PBMC) responses pre- and postchallenge. In contrast to Norwalk virus (NV), SMV infection was not dependent upon blood group secretor status. Nine of 15 volunteers were infected and showed a ≥4-fold increase over the prechallenge anti-SMV serum immunoglobulin G (IgG) titer, mostly subclass IgG1. Although serum IgG elicited by SMV infection was cross-reactive with Hawaii virus (HV), another genogroup 2 norovirus, salivary IgA was less cross-reactive. Neither SMV-elicited serum IgG nor salivary IgA cross-reacted with NV, a genogroup 1 norovirus. Significant increases in serum gamma interferon (IFN-γ) and IL-2, but not IL-6 or IL-10, were noted on day 2 postchallenge. For the majority of volunteers, both infected and uninfected, PBMCs stimulated with norovirus virus-like particles secreted IFN-γ and other Th1 cytokines, suggesting previous norovirus exposure in most volunteers. Like the IgG antibodies, the SMV-activated T cells were cross-reactive with HV but not NV. IFN-γ production was dependent upon CD4+ cells, consistent with a predominant, but not exclusive, Th1 response. To our knowledge, this is the first report characterizing T-cell and cytokine responses following live norovirus challenge.

scholarly journals Prevalence of Human Calicivirus Infections in Kenya as Determined by Enzyme Immunoassays for Three Genogroups of the Virus

1998 ◽  
Vol 36 (11) ◽  
pp. 3160-3163 ◽  
Author(s):  
Shuji Nakata ◽  
Shinjiro Honma ◽  
Kazuko Numata ◽  
Keiko Kogawa ◽  
Susumu Ukae ◽  
...  
Keyword(s):  
Serum Antibody ◽  
Epidemiological Survey ◽  
Outpatient Clinics ◽  
Norwalk Virus ◽  
Serum Samples ◽  
Enzyme Immunoassays ◽  
Immunological Responses ◽  
Age Related ◽  
Severe Infections ◽  
Stool Samples

An epidemiological survey on human calicivirus (HuCV) infections and associated gastroenteritis in infants was conducted to clarify the prevalence of HuCV infections in infants and adults in Kenya. Enzyme immunoassays (EIAs) for three genogroups of HuCVs, Norwalk virus (NV), Mexico virus (MXV), and Sapporo virus (SV), were used to detect antigen or antibody. We tested 1,431 stool samples obtained from children younger than 6 years old with acute gastroenteritis who visited outpatient clinics in three districts in Kenya from August 1991 to July 1994. Thirty-two (2.2%) of these stool samples were positive for SV antigen. Only one (0.1%) of 1,186 samples was positive for NV antigen and none of 246 samples was positive for MXV antigen. One hundred ninety-three serum samples were tested for antibodies to NV and MXV, and 64 of them were examined for antibody to SV. The pattern of the age-related prevalence of serum antibody to NV was different from that of antibodies to MXV and SV. The acquisition of serum antibodies to HuCVs in the three genogroups appeared in early childhood, at about 1 to 2 years of age. The prevalence of serum antibody to NV was low (about 60%) throughout adulthood compared with a high prevalence of antibody (∼80 to 90%) to MXV and SV. These data indicate that infections with viruses in the three genogroups of HuCVs are common in Kenya, and immunological responses to NV may be different from those to MXV and SV. The EIAs for the detection of NV and MXV antigens appear to be quite specific for prototype NV and MXV strains, respectively, so that they can detect only a few strains of HuCVs related to them. Alternatively, NV and MXV caused less severe infections that did not bring children to the outpatient clinics for gastroenteritis in Kenya.

scholarly journals Comparing Five SARS-CoV-2 Antibody Assay Results Before and After the First and Second ChAdOx1 nCoV-19 Vaccination Among Health Care Workers: A Prospective Multicenter Study

2021 ◽  
Author(s):  
Seri Jeong ◽  
Nuri Lee ◽  
Su Kyung Lee ◽  
Eun-Jung Cho ◽  
Jungwon Hyun ◽  
...  
Keyword(s):  
Health Care Workers ◽  
Adverse Reactions ◽  
Neutralizing Antibody ◽  
Fold Increase ◽  
Serum Samples ◽  
Prospective Multicenter Study ◽  
Care Workers ◽  
Before And After ◽  
Antibody Assays ◽  
Antibody Titers

Reliable results for serologic positivity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody after the second dose of AstraZeneca (AZ) vaccination are important to estimate the real efficacy of vaccination. We evaluated the positivity rates and the changes of semi-quantitative antibody titers before and after the first and second ChAdOx1 nCoV-19 Vaccinations using five SARS-CoV-2 antibody assays, including two surrogate virus neutralization tests. A total of 674 serum samples were obtained from 228 participants during three blood sampling periods. A questionnaire on symptoms, severity and adverse reactions duration was completed after the second vaccination. The overall positive rates for all assays were 0.0-0.9% before vaccination, 66.2-92.5% after the first vaccination, and 98.2-100.0% after the second vaccination. Median antibody titers in five assays after the second dose of vaccination were increased compared to those after the first dose (106.4-fold increase for Roche total antibody, 3.6-fold for Abbott IgG, 3.6-fold for Siemens, 1.2-fold for SD Biosensor V1 neutralizing antibody, and 2.2-fold for GenScript neutralizing antibody). Adverse reactions reduced after the second dose in 89.9% of participants compared to after the first dose. Overall, the second vaccination led to almost 100% positivity rates based on these SARS-CoV-2 antibody assays. The results should be interpreted with caution, considering the characteristics of applied assays. Our findings could inform decisions regarding vaccination and the use of immunoassays, thus, contributing to the SARS-CoV-2 pandemic control.

Autoantibodies to Thrombomodulin: Development of an Enzyme Immunoassay and a Survey of their Frequency in Patients with the Lupus Anticoagulant

1992 ◽  
Vol 67 (05) ◽  
pp. 507-509 ◽  
Author(s):  
John Gibson ◽  
Margaret Nelson ◽  
Ross Brown ◽  
Hatem Salem ◽  
Harry Kronenberg
Keyword(s):  
Enzyme Immunoassay ◽  
Lupus Anticoagulant ◽  
Specific Binding ◽  
Technical Problem ◽  
Serum Samples ◽  
Citrate Buffer ◽  
The Mean ◽  
Sample Dilution ◽  
Negative Population ◽  
Serum Components

SummaryIn order to investigate the possibility that autoantibodies to thrombomodulin (TM) may exist in patients with the lupus anticoagulant (LA) and perhaps be implicated in the pathogenesis of recurrent thrombosis seen in such patients, we developed an enzyme-immunoassay to screen serum samples for anti-human TM activity. The major technical problem encountered in developing this assay was to reduce the non-specific binding of serum components from both the LA positive and the negative population. Considerable reduction of non-specific binding was achieved by use of a phosphate/citrate buffer at pH 8.0 and the use of an optimal sample dilution of 1/40. In addition, samples were always tested in parallel in blank wells and results are expressed as an OD ratio. Samples from 113 patients with the LA were assayed and compared to 78 patients referred for LA testing but found to be negative. The mean OD values for the LA positive patients (± SD) was 1.36 (0.44) with a range of 0.78-2.57. This was virtually identical to the values for the LA negative population (1.38 ± 0.40, range 0.76-2.77). The results of this study indicate that there is no evidence for the presence of a significant autoantibody activity to TM in patients with the LA when compared to LA negative patients. If such autoantibodies do exist their frequency must be quite low.

MONITORING STUDIES OF ARBOVIRUS INFECTIONS TRANSMITTED BY MOSQUITOES ON THE TERRITORY OF THE VOLGOGRAD REGION

2019 ◽  
pp. 60-66
Author(s):  
E.V. Molchanova ◽  
D.N. Luchinin ◽  
A.O. Negodenko ◽  
D.R. Prilepskaya ◽  
N.V. Boroday ◽  
...  
Keyword(s):  
Virus Antigen ◽  
Elisa Test ◽  
Serum Samples ◽  
Blood Sucking ◽  
Tick Borne Encephalitis ◽  
Volgograd Region ◽  
Two Samples ◽  
Probable Presence ◽  
California Serogroup ◽  
Tick Borne Encephalitis Virus

The paper presents data from the monitoring studies’ results of arbovirus infections transmitted by mosquitoes in the Volgograd region. West Nile virus antigen (WNV) in 9 samples, Tahyna virus in one sample, Batai virus in two samples were detected in the study of 110 samples of field material (blood-sucking mosquitoes) by ELISA test. Antibodies to WNV in 16.58 percent of the samples, to tick-borne encephalitis virus in 1.08 percent, to viruses of the California serogroup and Ukuniemi in 1.09 percent, to the virus Sindbis in 2.17 percent were detected as a result of the study of blood serum samples from donors in the Volgograd region. Thus, we obtained data on the probable presence of the Batai, Sindbis, Ukuniemi and Californian serogroup viruses along with the circulation of WNV on the territory of the Volgograd region.

scholarly journals Population (Antibody) Testing for COVID-19—Technical Challenges, Application and Relevance, an English Perspective

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 550
Author(s):  
Peter A. C. Maple
Keyword(s):  
National Level ◽  
Herd Immunity ◽  
Population Based ◽  
Biological Properties ◽  
Limited Extent ◽  
Antibody Testing ◽  
Serum Samples ◽  
Oral Fluids ◽  
Antibody Assays ◽  
The Uk

In the UK, population virus or antibody testing using virus swabs, serum samples, blood spots or oral fluids has been performed to a limited extent for several diseases including measles, mumps, rubella and hepatitis and HIV. The collection of population-based infection and immunity data is key to the monitoring of disease prevalence and assessing the effectiveness of interventions such as behavioural modifications and vaccination. In particular, the biological properties of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its interaction with the human host have presented several challenges towards the development of population-based immunity testing. Measuring SARS-CoV-2 immunity requires the development of antibody assays of acceptable sensitivity and specificity which are capable of accurately detecting seroprevalence and differentiating protection from non-protective responses. Now that anti-COVID-19 vaccines are becoming available there is a pressing need to measure vaccine efficacy and the development of herd immunity. The unprecedented impact of the SARS-CoV-2 pandemic in the UK in terms of morbidity, mortality, and economic and social disruption has mobilized a national scientific effort to learn more about this virus. In this article, the challenges of testing for SARS-CoV-2 infection, particularly in relation to population-based immunity testing, will be considered and examples given of relevant national level studies.

scholarly journals Measurement of IgA responses following Norwalk virus infection and other human caliciviruses using a recombinant Norwalk virus protein EIA

1994 ◽  
Vol 113 (1) ◽  
pp. 143-151 ◽  
Author(s):  
S. P. Parker ◽  
W. D. Cubitt
Keyword(s):  
Virus Infection ◽  
Enzyme Immunoassay ◽  
Capsid Protein ◽  
Causative Agent ◽  
Food Poisoning ◽  
Hospital Staff ◽  
Virus Protein ◽  
Norwalk Virus ◽  
Major Outbreak ◽  
Virus Capsid Protein

SUMMARYAn enzyme immunoassay employing recombinant Norwalk virus capsid protein was evaluated for the measurement of IgA responses. Tests on 23 volunteers and patients known to have been infected with Norwalk virus (NV) showed that 19 developed significant IgA responses, 2 had unchanging levels of IgA and 2 failed to respond. There was no evidence of IgA responses to NV following infection with Hawaii or Snow Mountain-like viruses.Tests on sera from patients involved in outbreaks associated with eating contaminated shellfish suggest that some patients may have been infected with more than one strain of calicivirus. The use of the rNV EIA for measuring IgA and IgG responses in patients involved in a major outbreak of food poisoning affecting hospital staff indicated that the causative agent was probably NV.

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