Development of a Microsphere-based Immunoassay for Serological Detection of African Horse Sickness Virus and Comparison with Other Diagnostic Techniques

Abstract

African horse sickness (AHS) is a viral disease that causes high morbidity and mortality rates in susceptible Equidae and therefore significant economic losses. More rapid, sensitive and specific assays are required by diagnostic laboratories to support effective surveillance programmes. A novel microsphere-based immunoassay (Luminex assay) in which beads are coated with recombinant AHS virus (AHSV) structural protein 7 (VP7) has been developed for serological detection of antibodies against VP7 of any AHSV serotype. The performance of this assay was compared with that of a commercial enzyme-linked immunosorbent assay (ELISA) and commercial lateral flow assay (LFA) on a large panel of serum samples from uninfected horses (n = 92), from a reference library of all AHSV serotypes (n = 9), on samples from horses experimentally infected with AHSV (n = 114), and on samples from West African horses suspected of having AHS (n = 85). The Luminex assay gave the same negative results as ELISA when used to test the samples from uninfected horses. Both assays detected antibodies to all nine AHSV serotypes. In contrast, the Luminex assay detected a higher rate of anti-VP7 positivity in the West African field samples than did ELISA or LFA. The Luminex assay detected anti-VP7 positivity in experimentally infected horses at 7 days post-infection, compared to 13 days for ELISA. This novel immunoassay provides a platform for developing multiplex assays, in which the presence of antibodies against multiple ASHV antigens can be detected simultaneously. This would be useful for serotyping or for differentiating infected from vaccinated animals.

Fluorescent microbead-based immunoassay for anti-Erysipelothrix rhusiopathiae antibody detection in cetaceans

“…FMIA can be more sensitive than traditional immunoassays (van Gageldonk et al 2008, Giménez-Lirola et al 2012, Sánchez-Matamoros et al 2015. Although FMIA, based on Luminex's xMAP technology, has been used successfully in veterinary disease research (Clavijo et al 2006, Anderson et al 2011, Wagner et al 2011, Giménez-Lirola et al 2012, ChristopherHennings et al 2013, Sánchez-Matamoros et al 2015, the present study is, to the best of our knowledge, the first application of FMIA to cetaceans.…”

Comparison of Immunologic Responses Following Intranasal and Oral Administration of a USDA-Approved, Live-Attenuated Streptococcus equi Vaccine

“…The MIA was found to have a lower limit of detection compared to commercial kits indicating it is more sensitive, and the MIA had similar specificity to the ELISA while the LFA was unreliable (Sanchez-Matamoros et al 2015).…”

“…Microsphere immunoassays have been developed to detect serologic responses to a variety of equine diseases including West Nile virus (WNV) (Balasuriya et al 2006), flavivirusassociated neurologic diseases , equine viral arteritis (Go et al 2008), African horse sickness (Sanchez-Matamoros et al 2015), Lyme disease (Wagner et al 2011), andHendra virus (McNabb et al 2014). An MIA incorporating recombinant WNV envelope protein (rE) was found to have diagnostic sensitivity and specificity (99.3% and 97.4%, respectively) compared to plaque reduction neutralization test (PRNT) (Balasuriya et al 2006).…”

“…An MIA to detect African horse sickness (AHS) anti-viral particle (VP) 7 antibodies was developed and compared to commercial ELISA and lateral flow assay (LFA) kits for detection of anti-VP7 antibodies (Sanchez-Matamoros et al 2015). The MIA was found to have a lower limit of detection compared to commercial kits indicating it is more sensitive, and the MIA had similar specificity to the ELISA while the LFA was unreliable (Sanchez-Matamoros et al 2015).…”

The challenges posed by equine arboviruses

“…Although effective vaccines against WNV are available, there may be a desire to prohibit vaccination of horses in some countries so that they can fulfil the role of a sentinel species [55,56]. In the United States, multivalent vaccines are available that include WNV, EEEV, WEEV and VEEV.…”