Seroepidemiology for MERS coronavirus using microneutralisation and pseudoparticle virus neutralisation assays reveal a high prevalence of antibody in dromedary camels in Egypt, June 2013

<div>We describe a novel spike pseudoparticle neutralisation</div><div>assay (ppNT) for seroepidemiological studies on</div><div>Middle East respiratory syndrome coronavirus (MERSCoV)</div><div>and apply this assay together with conventional</div><div>microneutralisation (MN) tests to investigate 1,343</div><div>human and 625 animal sera. The sera were collected</div><div>in Egypt as a region adjacent to areas where MERS has</div><div>been described, and in Hong Kong, China as a control</div><div>region. Sera from dromedary camels had a high prevalence</div><div>of antibody reactive to MERS-CoV by MERS NT</div><div>(93.6%) and MERS ppNT (98.2%) assay. The antibody</div><div>titres ranged up to 1,280 and higher in MN assays</div><div>and 10,240 and higher in ppNT assays. No other</div><div>investigated species had any antibody reactivity to</div><div>MERS-CoV. While seropositivity does not exclude the</div><div>possibility of infection with a closely related virus, our</div><div>data highlight the need to attempt detection of MERSCoV</div><div>or related coronaviruses in dromedary camels. The</div><div>data show excellent correlation between the conventional</div><div>MN assay and the novel ppNT assay. The newly</div><div>developed ppNT assay does not require Biosafety Level</div><div>3 containment and is thus a relatively high-throughput</div><div>assay, well suited for large-scale seroepidemiology</div><div>studies which are needed to better understand the</div><div>ecology and epidemiology of MERS-CoV.</div