Detection of Lassa Virus Antinucleoprotein Immunoglobulin G (IgG) and IgM Antibodies by a Simple Recombinant  Immunoblot Assay for Field Use

The nucleoprotein of Lassa virus, strain Josiah, was expressed inEscherichia coli as an N-terminally truncated, histidine-tagged recombinant protein. Following affinity purification the protein was completely denatured and spotted onto nitrocellulose membrane. A total of 1 μg of protein was applied for detection of Lassa virus antibodies (LVA) in a simple immunoblot assay. Specific anti-Lassa immunoglobulin M (IgM) antibodies could be detected by increasing the amount of protein to 5 μg. A panel of 913 serum specimens from regions in which Lassa virus was endemic and from regions in which Lassa virus was not endemic was used for evaluating the sensitivity and specificity of the LVA immunoblot in comparison to those of an indirect immunofluorescence (IIF) assay. The sera originated from field studies conducted in the Republic of Guinea (570 serum samples) and Liberia (99 serum samples), from inpatients of the clinical department of the Bernhard-Nocht-Institute, Hamburg, Germany (94 serum samples), and from healthy German blood donors (150 serum samples). In comparison to the IIF assay the LVA immunoblot assay had a specificity of 90.0 to 99.3%, depending on the origin of the specimens. The sensitivity was found to be highest for the Guinean samples (90.7%) and was lower for the Liberian samples (75%). Acute Lassa fever was diagnosed by PCR in 12 of 59 (20.3%) patients with fever of unknown origin (FUO) from the Republic of Guinea. On admission to the hospital, nine Lassa fever patients (75%) were reactive by the IgM immunoblot assay. One of the patients was infected with a new Lassa variant, which showed 10.4% variation on the amino acid level in comparison to the prototype strain of Lassa virus, Josiah. Seven PCR-negative patients were reactive by immunoblotting. The positive and negative predictive values of a single IgM immunoblot result for acute, PCR-confirmed Lassa fever were therefore 53.6 and 93.0%, respectively. Because of its high negative predictive value, a single IgM immunoblot result will be valuable for excluding acute Lassa fever for cases of FUO in areas where Lassa fever is endemic.

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Statistical Distribution of Lassa Fever in Edo State, Nigeria

Asian Journal of Probability and Statistics ◽

10.9734/ajpas/2021/v15i430366 ◽

2021 ◽

pp. 88-96

Author(s):

Nwaigwe, Chrysogonus Chinagorom ◽

Bartholomew, Desmond Chekwube ◽

Eze, Petra Adachukwu

Keyword(s):

Goodness Of Fit ◽

Lassa Fever ◽

Statistical Distribution ◽

Lassa Virus ◽

Goodness Of Fit Test ◽

Republic Of Guinea ◽

Edo State ◽

The Republic ◽

Discrete Uniform ◽

Access To Food

Lassa fever is a severe viral infection caused by the Lassa virus and spread by contact with excretions or secretions of infected rats gaining access to food and water inside human houses and other human activity areas. Sierra Leone, the Republic of Guinea, Nigeria, and Liberia are among the nations where it is endemic with a high number of deaths recorded yearly due to Lassa fever. In Nigeria, one of the states with the highest incidence is Edo. In order to reduce and predict the spread of Lassa fever in Edo state, the trend of the disease needs to be understood. Knowledge of the statistical distribution of a disease is one of the best ways to understand the trend of the disease. Currently, existing research on the statistical distribution of Lassa fever is very rare. The present work is an attempt to initiate research on the statistical distribution of Lassa fever with data obtained on weekly cases of Lassa Fever in Edo State, Nigeria. Based on the Kolmogorov Smirnoff and Anderson Darling’s goodness of fit test for fitting distribution, the Geometric distribution outfitted the weekly confirmed incidences of Lassa fever in Edo State, Nigeria when compared with the Discrete Uniform and Poisson distributions. The study further revealed that on the average, two Lassa fever cases is recorded per week in Edo State within the study period. This number of cases per week is on the high side and should be immediately looked into.

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Development of Recombinant Nucleoprotein-Based Diagnostic Systems for Lassa Fever

Clinical and Vaccine Immunology ◽

10.1128/cvi.00101-07 ◽

2007 ◽

Vol 14 (9) ◽

pp. 1182-1189 ◽

Cited By ~ 36

Author(s):

Masayuki Saijo ◽

Marie-Claude Georges-Courbot ◽

Philippe Marianneau ◽

Victor Romanowski ◽

Shuetsu Fukushi ◽

...

Keyword(s):

Monoclonal Antibody ◽

Hela Cells ◽

Recombinant Baculovirus ◽

Lassa Fever ◽

Rabbit Serum ◽

Enzyme Linked Immunosorbent Assay ◽

Lassa Virus ◽

Diagnostic Systems ◽

Serum Samples ◽

Capture Elisa

ABSTRACT Diagnostic systems for Lassa fever (LF), a viral hemorrhagic fever caused by Lassa virus (LASV), such as enzyme immunoassays for the detection of LASV antibodies and LASV antigens, were developed using the recombinant nucleoprotein (rNP) of LASV (LASV-rNP). The LASV-rNP was expressed in a recombinant baculovirus system. LASV-rNP was used as an antigen in the detection of LASV-antibodies and as an immunogen for the production of monoclonal antibodies. The LASV-rNP was also expressed in HeLa cells by transfection with the expression vector encoding cDNA of the LASV-NP gene. An immunoglobulin G enzyme-linked immunosorbent assay (ELISA) using LASV-rNP and an indirect immunofluorescence assay using LASV-rNP-expressing HeLa cells were confirmed to have high sensitivity and specificity in the detection of LASV-antibodies. A novel monoclonal antibody to LASV-rNP, monoclonal antibody 4A5, was established. A sandwich antigen capture (Ag-capture) ELISA using the monoclonal antibody and an anti-LASV-rNP rabbit serum as capture and detection antibodies, respectively, was then developed. Authentic LASV nucleoprotein in serum samples collected from hamsters experimentally infected with LASV was detected by the Ag-capture ELISA. The Ag-capture ELISA specifically detected LASV-rNP but not the rNPs of lymphocytic choriomeningitis virus or Junin virus. The sensitivity of the Ag-capture ELISA in detecting LASV antigens was comparable to that of reverse transcription-PCR in detecting LASV RNA. These LASV rNP-based diagnostics were confirmed to be useful in the diagnosis of LF even in institutes without a high containment laboratory, since the antigens can be prepared without manipulation of the infectious viruses.

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Evaluation of an Immunoglobulin M Capture Enzyme-Linked Immunosorbent Assay for Diagnosis of Orientia tsutsugamushi Infection

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.3.394-398.2003 ◽

2003 ◽

Vol 10 (3) ◽

pp. 394-398 ◽

Cited By ~ 19

Author(s):

Won-Jong Jang ◽

Myung-Suk Huh ◽

Kyung-Hee Park ◽

Myung-Sik Choi ◽

Ik-Sang Kim

Keyword(s):

Immunosorbent Assay ◽

Scrub Typhus ◽

Microtiter Plate ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Orientia Tsutsugamushi ◽

Serum Samples ◽

Capture Elisa ◽

Igm Antibodies ◽

Immunodominant Antigen

ABSTRACT To differentiate scrub typhus from other acute febrile diseases, a rapid and reliable serological diagnosis is important. We developed an immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (ELISA) for diagnosis of recent Orientia tsutsugamushi infections in humans. The 56-kDa major outer membrane protein of O. tsutsugamushi is well known as the most immunodominant antigen in scrub typhus. The test is based on the use of the biotinylated recombinant 56-kDa protein of O. tsutsugamushi Boryong, Bor56, which was expressed as a fusion protein with a maltose-binding protein in Escherichia coli. In the test, the serum IgM antibodies were captured by anti-human IgM antibodies coated onto a microtiter plate. The captured IgM antibodies were revealed through sequential addition of biotinylated Bor56 antigen and peroxidase-conjugated streptavidin to the plate. The IgM capture ELISA was compared with the immunofluorescence antibody assay (IFA) by testing 176 serum samples from patients with diagnosed cases of rickettsial disease and patients with other acute febrile diseases. Of the 81 IgG IFA-positive samples, 78 tested positive (sensitivity, 96.3%) and all 31 IgM IFA-positive samples tested positive (sensitivity, 100%) by the IgM capture ELISA. The specificity of the IgM capture ELISA was 99%, and 1 of the 95 IFA-negative samples was positive in the assay. These results strongly suggest that IgM capture ELISA using the recombinant Bor56 antigen is a reliable and detailed method for the detection of early O. tsutsugamushi infection.

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Detection of measles cases in the Republic of Guinea in 2017–2018

Russian Journal of Infection and Immunity ◽

10.15789/2220-7619-dom-1333 ◽

2020 ◽

Vol 10 (3) ◽

pp. 570-574

Author(s):

I. N. Lavrentieva ◽

M. A. Bichurina ◽

A. Y. Antipova ◽

J. Camara ◽

N.F. Magassouba

Keyword(s):

Antibody Level ◽

Measles Virus ◽

Age Groups ◽

Cold Chain ◽

Epidemiological Surveillance ◽

Serum Samples ◽

Igg Antibody ◽

Republic Of Guinea ◽

Measles Vaccination ◽

The Republic

In 2017, WHO reported 596 confirmed measles cases in Guinea Republic connected to the 2016–2017 epidemic outbreak that was stopped after additional immunization (SIA) against measles in two provinces of the country. Improving the effectiveness of SIA is associated with the identification of epidemiologically significant groups of the population. The aim of the study was to analyze 2017–2018 measles cases and assess population immunity to measles virus in the Republic of Guinea. Materials and methods. A total of 810 blood serum samples collected from patients with maculo-papular rash and clinical diagnosis “measles?” were tested for measles virus-specific IgM-and IgG antibody level. 445 sera of conditionally healthy individuals aged 7 months to 67 years were examined for anti-measles virus IgG antibody level. Immunoglobulins of classes M and G were detected by ELISA with test systems «Anti-Measles Virus ELISA (IgM)» (Euro immun, Germany) and «Anti-Measles Virus ELISA (IgG)» (Euroimmun, Germany). Results and discussion.In 2017–2018, the epidemic process of the measles in the Republic of Guinea proceeded very intensively, being markedly prevalent in children among age groups. In 2018, more than half of the cases (61.6%) were identified in children aged 1 to 5 years old; the second most abundant age group was children under one year (18.6%), probably due to violated measles vaccination, which in GR are subject to children of nine months of age. It was found that 16.4% of patients (60 out of 366) had documented data on measles vaccination. Potentially, high proportion of measles cases among pre-vaccinated subjects was due to insufficient immune response to a single immunization in children of 9 months of age. Moreover, lowered vaccine-related properties might also be violated “cold chain” during vaccine transportation occurring in tropical climate. Analyzing 445 subjects revealed that total number of measles virus seronegative subjects was 8.3%. However, the vast majority of them were children and young adults aged 7 months to 22 years, where 52.4% of seronegative subjects were identified. Thus, the data obtained indicate that intensive measles virus circulation in human population was continued that necessitate interventions for improving epidemiological surveillance, extend routine measles vaccination coverage and conduct SIAs against measles in GR.

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Study of the prevalence of antibodies to some arboviruses in the population of the Republic of Guinea

Voprosy Virusologii ◽

10.36233/0507-4088-74 ◽

2021 ◽

Vol 66 (5) ◽

pp. 346-353

Author(s):

E. V. Naidenova ◽

M. Yu. Kartashov ◽

K. S. Zakharov ◽

A. P. Shevtsova ◽

M. G. Diallo ◽

...

Keyword(s):

Clinical Signs ◽

Hemorrhagic Fever ◽

Serum Samples ◽

African Region ◽

Republic Of Guinea ◽

Disease Patterns ◽

Urgent Task ◽

The Republic ◽

Total Structure ◽

Batai Virus

Introduction. Acute febrile diseases kill more than 250,000 people annually in West Africa. Malaria and typhoid fever traditionally occupy most of the total structure of registered fevers. However, these data do not fully reflect the true overall disease patterns in the West African region. This is due to the fact that diagnosis is mainly based on the clinical signs of the infectious process, suggesting that a certain number of diseases may be caused by arboviruses. The detection of specific antibodies (ABs) to infectious pathogens in the blood sera of residents of a particular area is a reliable indicator of the circulation of these pathogens in a particular territory.The aim of this study was to determine the prevalence of antibodies to a number of arboviruses: Dengue (DENV), West Nile (WNV) (family Flaviviridae), Crimean-Congo hemorrhagic fever (orthonairo)virus (CCHFV), Batai (Batai virus), Bhanja (BHAV) (order Bunyavirales), Chikungunya (CHIKV), and Sindbis (SINV) (family Togaviridae) in the population of the Republic of Guinea.Material and methods. In total, a panel of 2,620 blood serum samples from people living in all landscape and geographical areas of Guinea was collected for the study. Detection of IgG antibodies was performed using an enzyme-linked immunoassay (ELISA).Results. In total, ABs to Batai virus were detected in 144 samples (5.5%), BHAV in 58 (2.2%), WNV in 892 (34.0 %), DENV in 659 (25.2 %), CCHFV in 58 (2.2 %), CHIKV in 339 (12.9 %), and SINV in 52 samples (2.0 %).Discussion. The obtained results indicate serological evidence of the spectrum of arboviruses in the population of all landscape and geographical zones of the Republic of Guinea, confirming their active circulation in this territory.Conclusion. Given the high epidemiological significance of arbovirus infectious diseases, it is an urgent task to continue studying its share in the structure of febrile diseases in the territory of the Republic of Guinea.

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Serum antibodies to phosphatidylcholine in MS

Neurology Neuroimmunology & Neuroinflammation ◽

10.1212/nxi.0000000000000765 ◽

2020 ◽

Vol 7 (4) ◽

pp. e765 ◽

Cited By ~ 1

Author(s):

Maria Cruz Sádaba ◽

Veit Rothhammer ◽

Úrsula Muñoz ◽

Cristina Sebal ◽

Esther Escudero ◽

...

Keyword(s):

Serum Levels ◽

Immunoglobulin M ◽

Class Iii ◽

Serum Antibodies ◽

Serum Samples ◽

Igm Antibodies ◽

Elisa Technique ◽

Antibody Levels ◽

And Control ◽

Control Samples

ObjectiveTo evaluate the value of serum immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies reactive with phosphatidylcholine (PC) and lactosylceramide (LC) as biomarkers in MS.MethodsWe developed an ultrasensitive ELISA technique to analyze serum IgG and IgM antibodies to LC and PC, which we used to analyze samples from 362 patients with MS, 10 patients with non-MS myelin diseases (Non-MSMYDs), 11 patients with nonmyelin neurologic diseases (Non-MYNDs), and 80 controls. MS serum samples included clinically isolated syndrome (CIS, n = 17), relapsing-remitting MS (RRMS, n = 62), secondary progressive MS (SPMS, n = 50), primary progressive MS (PPMS, n = 37), and benign MS (BENMS, n = 36).ResultsWe detected higher levels of serum IgM antibodies to PC (IgM-PC) in MS than control samples; patients with CIS and RRMS showed higher IgM-PC levels than patients with SPMS, PPMS, and BENMS and controls. MS and control samples did not differ in serum levels of IgM antibodies reactive with LC, nor in IgG antibodies reactive with LC or PC.ConclusionsSerum IgM-PC antibodies are elevated in patients with MS, particularly during the CIS and RRMS phases of the disease. Thus, serum IgM-PC is a candidate biomarker for early inflammatory stages of MS.Classification of evidenceThis study provides Class III evidence that serum antibodies to PC are elevated in patients with MS. The study is rated Class III because of the case control design and the risk of spectrum bias: antibody levels in patients with MS were compared with healthy controls.

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Equine seroprevalence of West Nile virus antibodies in the UK in 2019

Parasites & Vectors ◽

10.1186/s13071-020-04481-9 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Arran J. Folly ◽

Elisabeth S. L. Waller ◽

Fiona McCracken ◽

Lorraine M. McElhinney ◽

Helen Roberts ◽

...

Keyword(s):

West Nile Virus ◽

Rna Virus ◽

Clinical History ◽

Immunoglobulin M ◽

Serum Samples ◽

West Nile ◽

Recent Infection ◽

Igm Antibodies ◽

Epidemiological Surveys ◽

The Uk

Abstract Background West Nile virus (WNV) is a single-stranded RNA virus that can cause neurological disease in both humans and horses. Due to the movement of competent vectors and viraemic hosts, WNV has repeatedly emerged globally and more recently in western Europe. Within the UK, WNV is a notifiable disease in horses, and vaccines against the virus are commercially available. However, there has been no investigation into the seroprevalence of WNV in the UK equine population to determine the extent of vaccination or to provide evidence of recent infection. Methods Equine serum samples were obtained from the Animal and Plant Health Agency’s equine testing service between August and November 2019. A total of 988 serum samples were selected for horses resident in South East England. WNV seroprevalence was determined using two enzyme-linked immunosorbent assays (ELISAs) to detect total flavivirus antibodies and WNV-specific immunoglobulin M (IgM) antibodies. Positive IgM results were investigated by contacting the submitting veterinarian to establish the clinical history or evidence of prior vaccination of the horses in question. Results Within the cohort, 274 samples tested positive for flavivirus antibodies, of which two subsequently tested positive for WNV-specific IgM antibodies. The follow-up investigation established that both horses had been vaccinated prior to serum samples being drawn, which resulted in an IgM-positive response. All the samples that tested positive by competition ELISA were from horses set to be exported to countries where WNV is endemic. Consequently, the positive results were likely due to previous vaccination. In contrast, 714 samples were seronegative, indicating that the majority of the UK equine population may be susceptible to WNV infection. Conclusions There was no evidence for cryptic WNV infection in a cohort of horses sampled in England in 2019. All IgM-seropositive cases were due to vaccination; this should be noted for future epidemiological surveys in the event of a disease outbreak, as it is not possible to distinguish vaccinated from infected horses without knowledge of their clinical histories.

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Development of an Immunoglobulin M (IgM) Capture Enzyme-Linked Immunosorbent Assay for Detection of Equine and Swine IgM Antibodies to Vesicular Stomatitis Virus

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.8.3.475-481.2001 ◽

2001 ◽

Vol 8 (3) ◽

pp. 475-481 ◽

Cited By ~ 10

Author(s):

En-min Zhou ◽

Jose Riva ◽

Alfonso Clavijo

Keyword(s):

Vesicular Stomatitis Virus ◽

Immunosorbent Assay ◽

Polyclonal Antibodies ◽

Competitive Elisa ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Igm Antibodies ◽

Vesicular Stomatitis ◽

Elisa Plate

ABSTRACT An immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (MC-ELISA) was developed for the detection of primary infection of vesicular stomatitis virus (VSV) in equine and swine sera. The test was based on the use of biotinylated sheep antibodies against equine or swine IgM molecules bound to a streptavidin-coated ELISA plate. The captured IgM antibodies were detected by application of antigens prepared from the New Jersey and the Indiana VSV serotypes (VSV-NJ and VSV-IN, respectively) and mouse polyclonal antibodies against VSV-NJ and VSV-IN. The MC-ELISA was compared to a competitive ELISA (C-ELISA) and the standard microtiter serum neutralization (MTSN) assay by testing serum samples from horses and pigs experimentally infected with VSV-NJ or VSV-IN. The MC-ELISA detected specific homologous IgM antibodies from equine and swine sera as early as 5 and 4 days postinfection (DPI), respectively, and as late as 35 DPI. The MTSN test also detected antibodies as early as 5 DPI and as late as 160 DPI. In a similar fashion, the C-ELISA detected antibodies from 6 to 7 DPI and as late as 160 DPI. These results demonstrated that the MC-ELISA is a useful test for serodiagnosis of primary VSV infection in horses and pigs.

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Comparison of three anti-coccidioides antibody enzyme immunoassay kits for the diagnosis of coccidioidomycosis

Medical Mycology ◽

10.1093/mmy/myz125 ◽

2020 ◽

Vol 58 (6) ◽

pp. 774-778 ◽

Cited By ~ 1

Author(s):

Joshua Malo ◽

Eric Holbrook ◽

Tirdad Zangeneh ◽

Chris Strawter ◽

Eyal Oren ◽

...

Keyword(s):

Enzyme Immunoassay ◽

Diagnostic Testing ◽

High Risk Patient ◽

Immunoglobulin M ◽

Antibody Detection ◽

Serum Samples ◽

Igg Antibody ◽

Igm Antibodies ◽

Igm Antibody ◽

Detection Specificity

Abstract Coccidioidomycosis is a common cause of community-acquired pneumonia in endemic areas of the southwestern United States. Clinical presentations range from self-limited disease to severe, disseminated disease. As such, early and accurate diagnosis is essential to ensure appropriate treatment and monitoring. Currently available diagnostic testing has variable accuracy, particularly in certain patient populations, and new tests may offer improved accuracy for the diagnosis of coccidioidomycosis. Serum samples from patients with coccidioidomycosis and controls were tested for immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies using the MVista Coccidioides antibody detection EIA and two commonly used commercial enzyme immunoassay (EIA) kits: the IMMY Omega EIA and the Meridian Premier EIA. The sensitivity of the IgG antibody detection was 87.4% using the MVista test compared to 46.6% for IMMY and 70.9% for Meridian. The sensitivity for IgM antibody detection was 61.2% for the MVista test, 22.3% for IMMY and 29.1% for Meridian. For IgG antibody detection, specificity was 90% for the MVista EIA, 94.6% for IMMY, 96.4% for Meridian. For IgM antibody detection, specificity was 95.3% for the MVista test 98.2% for IMMY and 99.1% for Meridian. The MVista Coccidioides antibody EIA offers improved sensitivity, including among high-risk patient populations, for the detection of IgG and IgM antibodies in comparison to other currently available EIAs.

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Anti-Hepatitis A Virus Immunoglobulin M Antibodies in Urine Samples for Rapid Diagnosis of Outbreaks

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.3.492-494.2003 ◽

2003 ◽

Vol 10 (3) ◽

pp. 492-494 ◽

Cited By ~ 5

Author(s):

Licel de los Angeles Rodríguez Lay ◽

Osmany Larralde Díaz ◽

Raiza Martínez Casanueva ◽

Aidonis Gutiérrez Moreno

Keyword(s):

Hepatitis A ◽

Hepatitis A Virus ◽

Rapid Diagnosis ◽

Immunoglobulin M ◽

Urine Samples ◽

Test Results ◽

Serum Samples ◽

Igm Antibodies ◽

Urine And Serum

ABSTRACT The main goal of this study was to test the feasibility of using urine for diagnosing hepatitis A virus (HAV) infections. A correlation of 90.78% between the test results of urine and serum samples was obtained. Four outbreaks of hepatitis A were confirmed by testing only urine samples. The levels of anti-HAV immunoglobulin M (IgM) antibodies in urine samples remained stable during 6 months of storage at −70°C but decreased when the samples were stored at 4°C. The results of tests of samples obtained 2 and 6 months after infection suggested that IgM levels decline more rapidly in urine than in serum.

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