scholarly journals Serum Neutralization Profiles of Straw-Colored Fruit Bats (Eidolon helvum) in Makurdi (Nigeria), against Four Lineages of Lagos Bat Lyssavirus

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2378
Author(s):  
Veronica Odinya Ameh ◽  
Guanghui Wu ◽  
Hooman Goharriz ◽  
Rebecca Shipley ◽  
Anthony R. Fooks ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Fluorescent Antibody ◽  
Virus Neutralization ◽  
Human Consumption ◽  
Fruit Bats ◽  
Serum Samples ◽  
Fatal Disease ◽  
Serum Neutralization ◽  
First Time ◽  
Eidolon Helvum

Lagos bat lyssavirus (LBV) comprising four lineages (A, B, C and D) can potentially cause the fatal disease rabies. Although LBV-B was initially isolated in Nigeria in 1956, there is no information on LBV lineages circulating in Nigeria. This study was undertaken for the first time to measure the neutralizing antibodies against four lineages of LBVs in straw-colored fruit bats (Eidolon helvum) in Makurdi, Nigeria. Serum samples (n = 180) collected during two periods (November 2017–March 2018 and November 2018–March 2019) from terminally bled bats captured for human consumption were tested using a modified fluorescent antibody virus neutralization (mFAVN) assay. A high proportion of bat sera (74%) neutralized at least one lineage of LBV (with reciprocal titers from 9 to >420.89) and most of them neutralized LBV-A (63%), followed by LBV-D (49%), LBV-C (45%) and LBV-B (24%). The majority of positive sera (75%, n = 100) neutralized multiple LBV lineages while the remaining 25% (n = 33) neutralized only a single lineage, i.e., LBV-A (n = 23), LBV-D (n = 8) and LBV-C (n = 2). None exclusively neutralized LBV-B. The results suggest that exposure to LBV is common in E. helvum and that LBV-A (but not LBV-B) is likely to be circulating in this region of Nigeria.

scholarly journals Predicting the presence and titer of rabies virus neutralizing antibodies from low-volume serum samples in low-containment facilities

2020 ◽  
Author(s):  
Diana K. Meza ◽  
Alice Broos ◽  
Daniel J. Becker ◽  
Abdelkader Behdenna ◽  
Brian J. Willett ◽  
...  
Keyword(s):  
Rabies Virus ◽  
Neutralizing Antibodies ◽  
Fluorescent Protein ◽  
Neutralization Test ◽  
Leukemia Virus ◽  
Fluorescent Antibody ◽  
Neutralizing Antibody ◽  
High Specificity ◽  
Virus Neutralization ◽  
Serum Samples

SummarySerology is a core component of the surveillance and management of viral zoonoses. Virus neutralization tests are a gold standard serological diagnostic, but requirements for large volumes of serum and high biosafety containment can limit widespread use. Here, focusing on Rabies lyssavirus, a globally important zoonosis, we developed a pseudotype micro-neutralization rapid fluorescent focus inhibition test (pmRFFIT) that overcomes these limitations. Specifically, we adapted an existing micro-neutralization test to use a green fluorescent protein–tagged murine leukemia virus pseudotype in lieu of pathogenic rabies virus, reducing the need for specialized reagents for antigen detection and enabling use in low-containment laboratories. We further used statistical analysis to generate rapid, quantitative predictions of the probability and titer of rabies virus neutralizing antibodies from microscopic imaging of neutralization outcomes. Using 47 serum samples from domestic dogs with neutralizing antibody titers estimated using the fluorescent antibody virus neutralization test (FAVN), pmRFFIT showed moderate sensitivity (78.79%) and high specificity (84.62%). Despite small conflicts, titer predictions were correlated across tests repeated on different dates both for dog samples (r = 0.93), and for a second dataset of sera from wild common vampire bats (r = 0.72, N = 41), indicating repeatability. Our test uses a starting volume of 3.5 μL of serum, estimates titers from a single dilution of serum rather than requiring multiple dilutions and end point titration, and may be adapted to target neutralizing antibodies against alternative lyssavirus species. The pmRFFIT enables high-throughput detection of rabies virus neutralizing antibodies in low-biocontainment settings and is suited to studies in wild or captive animals where large serum volumes cannot be obtained.

scholarly journals Detection of neutralizing antibodies against SARS-CoV-2 by using a commercial surrogate virus neutralization ELISA: can it substitute the classical neutralization test?

2021 ◽  
Author(s):  
Natalie E Hofmann ◽  
Marica Grossegesse ◽  
Markus Neumann ◽  
Lars Schaade ◽  
Andreas Nitsche
Keyword(s):  
Neutralizing Antibodies ◽  
Diagnostic Performance ◽  
Neutralization Test ◽  
Virus Neutralization ◽  
Serum Samples ◽  
Population Immunity ◽  
Vaccine Trials ◽  
Binding Inhibition ◽  
Antibody Titers ◽  
High Throughput Detection

Background: High-throughput detection of neutralizing antibodies against SARS-CoV-2 presents a valuable tool for vaccine trials or investigations of population immunity. We evaluate the performance of the first commercial surrogate virus neutralization test (sVNT, GenScript Biotech) against SARS-CoV-2 plaque reduction neutralization test (PRNT) in convalescent and vaccinated individuals. We compare it to five other ELISAs, two of which are designed to detect neutralizing antibodies. Results: In 491 pre-vaccination serum samples, sVNT missed 23.6% of PRNT-positive samples when using the manufacturer-recommended cutoff of 30% binding inhibition. Introducing a equivocal area between 15 and 35% maximized sensitivity and specificity against PRNT to 72.8-93.1 % and 73.5-97.6%, respectively. The overall diagnostic performance of the other ELISAs for neutralizing antibodies was below that of sVNT. Vaccinated individuals exhibited higher antibody titers by PRNT (median 119.8, IQR 56.7-160) and binding inhibition by sVNT (median 95.7, IQR 88.1-96.8) than convalescent patients (median 49.1, IQR 20-62; median 52.9, IQR 31.2-76.2). Conclusion: GenScript sVNT is suitable to screen for SARS-CoV-2-neutralizing antibodies; however, to obtain accurate results, confirmatory testing by PRNT in a equivocal area is required. This equivocal area may require adaptation for use in vaccinated individuals, due to higher antibody titers.

scholarly journals Safety and immunogenicity of a primary yellow fever vaccination under low-dose methotrexate therapy—a prospective multi-centre pilot study1

2020 ◽  
Vol 27 (6) ◽  
Author(s):  
Silja Bühler ◽  
Veronika Katharina Jaeger ◽  
Gilles Eperon ◽  
Hansjakob Furrer ◽  
Christoph A Fux ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Neutralizing Antibodies ◽  
Low Dose ◽  
Yellow Fever Virus ◽  
Serum Samples ◽  
Post Vaccination ◽  
Dose Methotrexate ◽  
Yellow Fever Vaccination ◽  
First Time ◽  
Local Side

Abstract Background More people on immunosuppression live in or wish to travel to yellow fever virus (YFV)-endemic areas. Data on the safety and immunogenicity of yellow fever vaccination (YFVV) during immunosuppression are scarce. The aim of this study was to compare the safety and immunogenicity of a primary YFVV between travellers on methotrexate and controls. Methods We conducted a prospective multi-centre controlled observational study from 2015 to 2017 in six Swiss travel clinics. 15 adults (nine with rheumatic diseases, five with dermatologic conditions and one with a gastroenterological disease) on low-dose methotrexate (≤20 mg/week) requiring a primary YFVV and 15 age and sex-matched controls received a YFVV. Solicited/unsolicited adverse reactions were recorded, YFV-RNA was measured in serum samples on Days 3, 7, 10, 14, 28 and neutralizing antibodies on Days 0, 7, 10, 14, 28. Results Patients´ and controls’ median ages were 53 and 52 years; 9 patients and 10 controls were female. 43% of patients and 33% of controls showed local side effects (P = 0.71); 86% of patients and 66% of controls reported systemic reactions (P = 0.39). YFV-RNA was detected in patients and controls on Day 3–10 post-vaccination and was never of clinical significance. Slightly more patients developed YFV-RNAaemia (Day 3: n = 5 vs n = 2, Day 7: n = 9 vs n = 7, Day 10: n = 3 vs n = 2, all P > 0.39). No serious reactions occurred. On Day 10, a minority of vaccinees was seroprotected (patients: n = 2, controls: n = 6). On Day 28, all vaccinees were seroprotected. Conclusions First-time YFVV was safe and immunogenic in travellers on low-dose methotrexate. Larger studies are needed to confirm these promising results.

scholarly journals Sero-Positivity of Japanese Encephalitis Virus in Equine Population of India Using IgG ELISA: Unraveling The Need for Vaccination

2021 ◽  
Author(s):  
Aarti Kapdi ◽  
HIMANI DHANZE ◽  
Anamika Sahu ◽  
Vijayata Singh ◽  
M. Suman Kumar ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Validation Studies ◽  
Horse Serum ◽  
Good Reproducibility ◽  
Ns1 Protein ◽  
Serum Samples ◽  
Fatal Disease ◽  
Kappa Value ◽  
Diagnostic Sensitivity And Specificity ◽  
First Time

Abstract Japanese encephalitis (JE) is a mosquito borne flaviviral zoonoses, causing fatal disease in equines and humans. JE is endemic in most of the states of India with occurrence of human cases every year. The horses are not vaccinated against JE in India and thus they are at more risk of acquiring the disease. Due to non-availability of indigenously developed ELISA and high cost of imported kits, regular sero-surveillance is not being carried out to assess the true picture of JE virus in equine population of India. Therefore, a recombinant NS1 protein based indirect IgG ELISA was developed with the objective to assess the sero-positivity of JE virus in equine population of India. The diagnostic sensitivity and specificity of developed ELISA was 84.73 % and 86.70 %, respectively. The validation studies revealed good reproducibility of ELISA with kappa value ranging from 0.75 to 1 between the results of different laboratories. A total of 2069 horse serum samples were screened using the developed ELISA and 401 samples were positive for IgG against JEV with an overall sero-positivity of 19.38% in equine population of India. A sero-positivity of 25.90% and 12.22% was recorded in Himachal Pradesh and Jammu-Kashmir, both hill states of North zone of India for the first time, revealing the spread of virus to the non-endemic parts of the country. The high sero-positivity of JE virus recorded in equine population warrants the need for initiation of vaccination of horses in India to prevent the morbidity and mortality.

scholarly journals Persistence of Multiple Paramyxoviruses in a Closed Captive Colony of Fruit Bats (Eidolon helvum)

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1659 ◽  
Author(s):  
Louise Gibson ◽  
Maria Puig Ribas ◽  
James Kemp ◽  
Olivier Restif ◽  
Richard D. Suu-Ire ◽  
...  
Keyword(s):  
Urban Areas ◽  
Emerging Diseases ◽  
Fruit Bats ◽  
Fatal Disease ◽  
Zoonotic Viruses ◽  
High Incidence ◽  
Natural Hosts ◽  
Free Ranging ◽  
Eidolon Helvum

Bats have been identified as the natural hosts of several emerging zoonotic viruses, including paramyxoviruses, such as Hendra and Nipah viruses, that can cause fatal disease in humans. Recently, African fruit bats with populations that roost in or near urban areas have been shown to harbour a great diversity of paramyxoviruses, posing potential spillover risks to public health. Understanding the circulation of these viruses in their reservoir populations is essential to predict and prevent future emerging diseases. Here, we identify a high incidence of multiple paramyxoviruses in urine samples collected from a closed captive colony of circa 115 straw-coloured fruit bats (Eidolon helvum). The sequences detected have high nucleotide identities with those derived from free ranging African fruit bats and form phylogenetic clusters with the Henipavirus genus, Pararubulavirus genus and other unclassified paramyxoviruses. As this colony had been closed for 5 years prior to this study, these results indicate that within-host paramyxoviral persistence underlies the role of bats as reservoirs of these viruses.

scholarly journals Persistence of Multiple Paramyxoviruses in a Closed Captive Colony of Fruit Bats (Eidolon helvum)

2021 ◽  
Author(s):  
Louise Gibson ◽  
Maria Puig Rebas ◽  
James Kemp ◽  
Olivier Restif ◽  
Richard D. Suu-Ire ◽  
...  
Keyword(s):  
Urban Areas ◽  
Emerging Diseases ◽  
Fruit Bats ◽  
Fatal Disease ◽  
Zoonotic Viruses ◽  
High Incidence ◽  
Natural Hosts ◽  
Free Ranging ◽  
Eidolon Helvum

Bats have been identified as the natural hosts of several emerging zoonotic viruses, including paramyxoviruses, such as Hendra and Nipah viruses, that can cause fatal disease in humans. Recently, African fruit bats with populations that roost in or near urban areas have been shown to harbour a great diversity of paramyxoviruses, posing potential spillover risks to public health. Understanding the circulation of these viruses in their reservoir populations is essential to predict and prevent future emerging diseases. Here, we identify a high incidence of multiple paramyxoviruses in urine samples collected from a closed, captive colony of circa. 115 straw-coloured fruit bats (Eidolon helvum). The sequences detected have high nucleotide identities with those derived from free ranging African fruit bats and form phylogenetic clusters with the Henipavirus genus, Pararubulavirus genus and other unclassified paramyxoviruses. As this colony had been closed for 5 years prior to this study, these results indicate that within-host paramyxoviral persistence underlies the role of bats as reservoirs of these viruses.

scholarly journals Attenuated infection by a Pteropine orthoreovirus isolated from an Egyptian fruit bat in Zambia

2021 ◽  
Vol 15 (9) ◽  
pp. e0009768
Author(s):  
Hayato Harima ◽  
Michihito Sasaki ◽  
Yasuko Orba ◽  
Kosuke Okuya ◽  
Yongjin Qiu ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Phylogenetic Analyses ◽  
Respiratory Illness ◽  
Replication Capacity ◽  
Fruit Bats ◽  
Rt Pcr ◽  
Fruit Bat ◽  
Eidolon Helvum ◽  
Severe Respiratory Illness ◽  
Generation Sequencing

Background Pteropine orthoreovirus (PRV) is an emerging bat-borne zoonotic virus that causes severe respiratory illness in humans. Although PRVs have been identified in fruit bats and humans in Australia and Asia, little is known about the prevalence of PRV infection in Africa. Therefore, this study performed an PRV surveillance in fruit bats in Zambia. Methods Egyptian fruit bats (Rousettus aegyptiacus, n = 47) and straw-colored fruit bats (Eidolon helvum, n = 33) captured in Zambia in 2017–2018 were screened for PRV infection using RT-PCR and serum neutralization tests. The complete genome sequence of an isolated PRV strain was determined by next generation sequencing and subjected to BLAST and phylogenetic analyses. Replication capacity and pathogenicity of the strain were investigated using Vero E6 cell cultures and BALB/c mice, respectively. Results An PRV strain, tentatively named Nachunsulwe-57, was isolated from one Egyptian fruit bat. Serological assays demonstrated that 98% of sera (69/70) collected from Egyptian fruit bats (n = 37) and straw-colored fruit bats (n = 33) had neutralizing antibodies against PRV. Genetic analyses revealed that all 10 genome segments of Nachunsulwe-57 were closely related to a bat-derived Kasama strain found in Uganda. Nachunsulwe-57 showed less efficiency in viral growth and lower pathogenicity in mice than another PRV strain, Miyazaki-Bali/2007, isolated from a patient. Conclusions A high proportion of Egyptian fruit bats and straw-colored fruit bats were found to be seropositive to PRV in Zambia. Importantly, a new PRV strain (Nachunsulwe-57) was isolated from an Egyptian fruit bat in Zambia, which had relatively weak pathogenicity in mice. Taken together, our findings provide new epidemiological insights about PRV infection in bats and indicate the first isolation of an PRV strain that may have low pathogenicity to humans.

scholarly journals Diagnostic Performance of Assays for the Detection of Anti-Porcine Reproductive and Respiratory Syndrome Virus Antibodies in Serum and Muscle Transudate (“Meat Juice”) Based on Samples Collected under Experimental Conditions

2008 ◽  
Vol 20 (6) ◽  
pp. 735-743 ◽  
Author(s):  
Ramon M. Molina ◽  
Wayne Chittick ◽  
Eric A. Nelson ◽  
Jane Christopher-Hennings ◽  
Raymond R. R. Rowland ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Neutralization Assay ◽  
Respiratory Syndrome Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Testing ◽  
Serum Samples ◽  
Experimental Conditions ◽  
Meat Juice

Three assays were evaluated for their ability to detect antibodies against Porcine reproductive and respiratory syndrome virus (PRRSV) in porcine muscle transudate (“meat juice”) samples. Samples were derived from 91 pigs inoculated with PRRSV isolate VR-2332 and 46 age-matched controls. Serum and muscle ( Musculus longissimus dorsi) samples were collected from randomly selected animals euthanized at ∼14-day intervals from 28 to 202 days postinoculation. Serum samples were assayed at a dilution of 1:40, and muscle transudate samples were assayed at 5 dilutions (1:2, 1:5, 1:10, 1:20, 1:40) using a commercial PRRSV antibody enzyme-linked immunosorbent assay (ELISA). In addition, muscle transudate samples were tested using an indirect fluorescent antibody test (IFAT) at 5 dilutions (1:2, 1:5, 1:10, 1:20, 1:40). Attempts to assay muscle transudate samples for neutralizing antibodies using a modified fluorescent focus neutralization assay were unsuccessful. Receiver operator characteristic (ROC) curve analyses were used to estimate cutoff thresholds and the associated diagnostic sensitivities and specificities for ELISA and IFAT at each dilution. For ELISA, muscle transudate samples at the ROC-optimized cutoffs were >95% sensitive and 100% specific at each dilution. At a cutoff dilution of ≥1:5, the IFAT diagnostic sensitivity and specificity of muscle transudate was estimated at 63.3% and 100%, respectively. These findings validated the use of muscle transudate samples in PRRSV surveillance programs based on ELISA antibody testing.

scholarly journals Occurrence of anti-Toxoplasma gondii antibodies and risk factors associated with infection in equids slaughtered for human consumption in Brazil

2020 ◽  
Vol 29 (3) ◽  
Author(s):  
Igor Falco Arruda ◽  
Wellington Alves de Freitas ◽  
Kênia de Fátima Carrijo ◽  
Paula Silva da Paz ◽  
Marianny Miranda Silva ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Animal Origin ◽  
Human Consumption ◽  
Serum Samples ◽  
Chi Square ◽  
Exact Test ◽  
Chi Square Test

Abstract Toxoplasmosis is a worldwide zoonosis caused by Toxoplasma gondii. Ingestion of raw/undercooked meat is considering an important route of infection. Consumption of meat from equids is common in European and Asian countries and an increase in Brazil has been observed. The aim of this study was to evaluate occurrences of anti-T. gondii antibodies and risk factors relating to infection in equids slaughtered for human consumption in Minas Gerais, Brazil. Blood samples from 192 horses and 208 donkeys were collected in the exsanguination area during the slaughter. Serum samples were subjected to the indirect fluorescent antibody test (IFAT). Association analysis was performed using Pearson’s chi-square test (χ2) or Fisher’s exact test, to evaluate risk factors relating to the prevalence of seroreagents. Antibodies against T. gondii were found in 13.5% of the equids, with higher occurrence in horses (18.75%) than in donkeys (8.65%). Associations between seropositivity and the following variables were found (p ≤ 0.05): species, animal origin, purpose of rearing and source of water for animal consumption and contact with cats. Farms need to implement preventive measures to control T. gondii infection in these species and avert transmission of the parasite to the human population that will consume their meat.

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

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