A sensitive and specific antigen detection assay for Middle East respiratory syndrome coronavirus

Chen, Yixin; Chan, Kwok-Hung; Kang, Yahong; Chen, Honglin; Luk, Hayes KH; Poon, Rosana WS; Chan, Jasper FW; Yuen, Kwok-Yung; Xia, Ningshao; Lau, Susanna KP; Woo, Patrick CY

Evaluation of the diagnostic test using control and simulated clinical specimens showed that the present ELISA is highly sensitive and specific for MERS-CoV. Using more than 120 NPAs positive with various respiratory viruses, we showed that the antigen capture ELISA is highly specific. Most importantly, NPAs positive for the four The present MERS-CoV-NP capture ELISA is potentially useful for detecting MERS-CoV in dromedary camel samples and screening other animal specimens for MERS-CoV. Although the ancestral origin of MERS-CoV is believed to be from bats, [29] [30] [31] dromedaries are likely to be the immediate animal reservoir for transmission of MERS-CoV to human. High titers of antibodies to MERS-CoV have been detected in more than 95% of adult dromedaries in the Middle East, 5, 9, 32, 33 and MERS-CoV have also been found from the nasal samples of a small proportion of dromedaries. 8, [34] [35] [36] As MERS-CoV was also detected in the nasal samples in dromedaries with viral loads of around 10 4 to 10 6 copies/mL, 37 the present ELISA should be readily useful for detecting MERS-CoV in dromedaries. To prevent MERS infections as well as in cases of MERS outbreaks, it may be necessary to screen and isolate dromedaries that are actively shedding MERS-CoV. Since the present ELISA captures MERS-CoV-NP antigen, it should be able to detect MERS-CoV regardless of the source of the specimen, and should be extremely useful for assessing viral shedding patterns in dromedaries as well as searching for other animal sources of MERS-CoV.