Evaluation of three commercial ELISA tests for serological detection of maedi-visna virus using Bayesian latent class analysis

Jerre, Anniken; Nordstoga, Anne Bang; Dean, Katharine R.; Holmøy, Ingrid Hunter

doi:10.1016/j.prevetmed.2022.105765

Cited by 9 publications

(6 citation statements)

References 18 publications

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“…Analysis of genetic sequences of SRLVs is important not only for evaluating the spread of SRLV types and subtypes, but also for monitoring antigenic variation. It is known that antigenic variation can be responsible for the misdiagnosis of highly divergent subtypes, since no test is capable of detecting all circulating strains of SRLVs [11,[44][45][46][47][48][49]. ELISA tests usually use the capsid protein as the antigen, so analysis of the epitope sequence of the gag-encoded protein is crucial.…”

Section: Discussionmentioning

confidence: 99%

First Molecular Characterization of Small Ruminant Lentiviruses Detected in Romania

Olech,

Hodor,

Toma

et al. 2023

Animals

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Small ruminant lentiviruses (SRLVs) are a group of retroviruses that cause multisystem chronic diseases in goats and sheep and lead to production losses in these animals, negatively affecting animal health and welfare. Although molecular characterization of SRLV field isolates has been performed in many countries, there is currently no information on SRLV genotypes circulating in sheep and goats in Romania. Therefore, the main objective of this study was to conduct a molecular and phylogenetic analysis of SRLVs from Romania and determine the degree of genetic relatedness of the obtained sequences to other known SRLV reference strains. A total of 81 sheep lung tissue samples and 41 sheep lung lymph node samples were tested using nested real-time PCR, and samples positive for real-time PCR were used to amplify an 800 bp gag-pol fragment and an overlapping 625 bp fragment of the gag gene. Pairwise DNA distance and phylogenetic analysis showed that the Romanian SRLV strains were closely related to the A2 and A3 strains based on gag-pol sequences and to the A3 and A17 subtypes based on gag sequences. No recombination events were found. Our results revealed that the Romanian sequences have similar epitope patterns to other existing subtypes, although E/K and R/K mutations in epitope 3 were found only in the Romanian sequences, which may have potential value in serological diagnosis. This study is the first report on the genetic characterization of SRLV strains circulating in Romania and provides new information on SRLV heterogeneity. Further detailed studies should be conducted to better understand the divergence of SRLV Romanian strains.

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Section: Discussionmentioning

confidence: 99%

First Molecular Characterization of Small Ruminant Lentiviruses Detected in Romania

Olech,

Hodor,

Toma

et al. 2023

Animals

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“…The specificity of monostrain ELISAs is usually high, but the sensitivity is extremely variable. Differences in the sensitivity of ELISA tests lead to contradictory results from these tests ( 2 , 4 , 24 , 36 , 76 , 99 , 161 ). The CAEV/MVV Total Ab test (IDEXX Switzerland AG, Liebefeld-Bern, Switzerland) has sensitivity of 98.6% and a specificity of 99.3%; however, this test could not detect animals infected with A4 strains, which reveals some limitations ( 27 ).…”

Section: Diagnostic Testingmentioning

confidence: 99%

The genetic variability of small-ruminant lentiviruses and its impact on tropism, the development of diagnostic tests and vaccines and the effectiveness of control programmes

Olech

2023

Journal of Veterinary Research

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Introduction Maedi-visna virus and caprine arthritis encephalitis virus are two closely related lentiviruses which cause multisystemic, progressive and persistent infection in goats and sheep. Because these viruses frequently cross the species barrier, they are considered to be one genetic group called small-ruminant lentiviruses (SRLV). They have in vivo tropism mainly for monocytes and macrophages and organ tropism with unknown mechanisms. Typical clinical signs are pneumonia in sheep, arthritis in goats, and mastitis in both species. Infection with SRLV cannot currently be treated or prevented, and control programmes are the only approaches to avoiding its spread. These programmes rely mainly on annual serological testing and elimination of positive animals. However, the high genetic and antigenic variability of SRLV complicate their early and definitive diagnosis. The objective of this review is to summarise the current knowledge of SRLV genetic variation and its implications for tropism, the development of diagnostic tests and vaccines and the effectiveness of control and eradication programmes. Material and Methods Subject literature was selected from the PubMed and the Google Scholar databases. Results The high genetic diversity of SRLV affects the performance of diagnostic tools and therefore control programmes. For the early and definitive diagnosis of SRLV infection, a combination of serological and molecular tests is suggested. Testing by PCR can also be considered for sub-yearling animals. There are still significant gaps in our knowledge of the epidemiology, immunology and biology of SRLV and their impact on animal production and welfare. Conclusion This information may aid selection of the most effective SRLV spread reduction measures.

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“…To evaluate the aSe and aSp, a preliminary cut-off value was defined for each antigen from the samples in panel 5 by defining samples as positive or negative based on ELISA results. The estimated diagnostic sensitivity and specificity, as well as the predictive values for the definition of ELISA-positive and negative samples when evaluated in the Norwegian sheep population, are described in Jerre et al [36]. Although misclassification of samples might have occurred, no perfect reference test to detect MVV infection exists; thus, misclassifications would have been possible if other tests had been used as well [5].…”

Section: Discussionmentioning

confidence: 99%

“…Although misclassification of samples might have occurred, no perfect reference test to detect MVV infection exists; thus, misclassifications would have been possible if other tests had been used as well [5]. The screening and verification of ELISA includes a mix of peptides from TM, SU and p25 antigens and TM and p28 antigens, respectively [28,36]. We regarded an ELISA-positive sample as positive towards all antigens in the multiplex assay.…”

Section: Discussionmentioning

confidence: 99%

Development of a Bead-Based Multiplex Fluorescent Immunoassay to Detect Antibodies against Maedi-Visna Virus in Sheep

Borge,

Colitti,

Rosati

et al. 2024

Animals

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The Maedi-visna virus (MVV) causes a persistent infection in small ruminants, and its high genetic heterogeneity affects the performance of diagnostic tests when used in different populations. Therefore, the aim of this study was to develop a bead-based multiplex immunoassay tailored to detect antibodies against a Norwegian MVV strain. We used tissue samples from 14 PCR-positive sheep from a recent MVV outbreak in Norway to sequence the viral strain and produced recombinant antigens based on sequences from one animal. The assay included commercial TM-A and recombinant Norwegian p25, p16–25 and SU5 antigens. Cut-off values for each antigen were determined using receiver operating characteristic curves on 40 ELISA-negative and 67 ELISA-positive samples from the outbreak. The intraplate and interplate repeatability were investigated by testing a quadruplicate of five samples over three days, while the analytical sensitivity (aSe) and specificity (aSp) were measured in comparison to a commercial ELISA. The repeatability showed a coefficient of variation below 15% for most positive samples. The aSe was equal or higher for the multiplex assay than the ELISA, and the aSp of each antigen was 91.7, 93.3, 95.0 and 93.3% for p25, p16–25, SU5 and TM-A, respectively. The assay shows promising results; however, further evaluations of diagnostic characteristics are necessary before implementation in the Norwegian surveillance programme.

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Evaluation of three commercial ELISA tests for serological detection of maedi-visna virus using Bayesian latent class analysis

Cited by 9 publications

References 18 publications

First Molecular Characterization of Small Ruminant Lentiviruses Detected in Romania

First Molecular Characterization of Small Ruminant Lentiviruses Detected in Romania

The genetic variability of small-ruminant lentiviruses and its impact on tropism, the development of diagnostic tests and vaccines and the effectiveness of control programmes

Development of a Bead-Based Multiplex Fluorescent Immunoassay to Detect Antibodies against Maedi-Visna Virus in Sheep

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