We present here a rapid immunochromatographic assay for the detection of Middle East respiratory syndrome coronavirus (MERS-CoV) antigen in the nasal swabs of dromedary camels. The assay is based on the detection of MERS-CoV nucleocapsid protein in a short time frame using highly selective monoclonal antibodies at room temperature. The relative sensitivity and specificity of the assay were found to be 93.90% and 100%, respectively, compared to that of the UpE and open reading frame 1A (Orf1A) real-time reverse transcriptase PCR (RT-PCR). The results suggest that the assay developed here is a useful tool for the rapid diagnosis and epidemiological surveillance of MERS-CoV infection in dromedary camels. Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly identified human coronavirus associated with severe pulmonary syndrome and renal failure in infected patients (1). To date, a total of 843 persons in 21 different countries have been infected by the virus, with a resulting 37.95% mortality rate (2). The current MERS-CoV outbreak investigations suggest that camels are a source of human infections. Nevertheless, the exact route of transmission from camels to humans remains unclear (3).MERS-CoV is primarily diagnosed using molecular techniques. These include real-time reverse transcriptase PCR (RT-PCR) (4, 5), reverse transcription-loop-mediated isothermal amplification (RT-LAMP) (6) and reverse transcription-recombinase polymerase amplification (RT-RTPA) (7). Moreover, several serological assays have been used to detect MERS-CoV or closely related viruses in seropositive camels. These are protein microarrays (8-10), a recombinant spike immunofluorescent assay (11, 12), indirect enzyme-linked immunosorbent assay (ELISA) (13), microneutralization, and spike pseudoparticle neutralization (14). However, none of the serological tests have provided proof of the precise presence of MERS-CoV in camels.Molecular tests are relatively expensive, not available in all laboratories, and are mainly used for confirmatory purposes. For the purpose of screening of large numbers of animals in a short period of time, molecular tests are considered impractical; therefore, a rapid, cheap, sensitive, and specific test is needed for the diagnosis of MERS-CoV in camels. Here, we report the development and validation of an immunochromatographic assay (ICA) for the rapid qualitative detection of MERS-CoV antigen in dromedary camels. The assay is based on the detection of MERS-CoV nucleocapsid protein by highly selective monoclonal antibodies. MATERIALS AND METHODSThis study was carried out in two phases during the period of August to October 2014. In the first phase, the ICA was developed at the BioNote laboratory (South Korea). In the second phase, the performance and validation of the ICA were carried out at the veterinary laboratories of the Abu Dhabi Food Control Authority (United Arab Emirates).Peptides and monoclonal antibody synthesis. At first, the hydrophilic regions of the nucleocapsid gene of MERS-CoV were analyzed b...

The objective of this research was to investigate the prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) infection primarily in dromedary camel farms and the relationship of those infections with infections in humans in the Emirate of Abu Dhabi. Nasal swabs from 1113 dromedary camels (39 farms) and 34 sheep (1 farm) and sputum samples from 2 MERS-CoV-infected camel farm owners and 1 MERS-CoV-infected sheep farm owner were collected. Samples from camels and humans underwent real-time reverse-transcription quantitative PCR screening to detect MERS-CoV. In addition, sequencing and phylogenetic analysis of partially characterized MERS-CoV genome fragments obtained from camels were performed. Among the 40 farms, 6 camel farms were positive for MERS-CoV; the virus was not detected in the single sheep farm. The maximum duration of viral shedding from infected camels was 2 weeks after the first positive test result as detected in nasal swabs and in rectal swabs obtained from infected calves. Three partial camel sequences characterized in this study (open reading frames 1a and 1ab, Spike1, Spike2, and ORF4b) together with the corresponding regions of previously reported MERS-CoV sequence obtained from one farm owner were clustering together within the larger MERS-CoV sequences cluster containing human and camel isolates reported for the Arabian Peninsula. Data provided further evidence of the zoonotic potential of MERS-CoV infection and strongly suggested that camels may have a role in the transmission of the virus to humans.

Camels are known carriers for many viral pathogens, including Middle East respiratory syndrome coronavirus (MERS-CoV). It is likely that there are additional, as yet unidentified viruses in camels with the potential to cause disease in humans. In this study, we performed metagenomic sequencing analysis on nasopharyngeal swab samples from 108 MERS-CoV-positive dromedary camels from a live animal market in Abu Dhabi, United Arab Emirates. We obtained a total of 846.72 million high-quality reads from these nasopharyngeal swab samples, of which 2.88 million (0.34%) were related to viral sequences while 512.63 million (60.5%) and 50.87 million (6%) matched bacterial and eukaryotic sequences, respectively. Among the viral reads, sequences related to mammalian viruses from 13 genera in 10 viral families were identified, including Coronaviridae, Nairoviridae, Paramyxoviridae, Parvoviridae, Polyomaviridae, Papillomaviridae, Astroviridae, Picornaviridae, Poxviridae, and Genomoviridae. Some viral sequences belong to known camel or human viruses and others are from potentially novel camel viruses with only limited sequence similarity to virus sequences in GenBank. A total of five potentially novel virus species or strains were identified. Co-infection of at least two recently identified camel coronaviruses was detected in 92.6% of the camels in the study. This study provides a comprehensive survey of viruses in the virome of upper respiratory samples in camels that have extensive contact with the human population.

Camel contact is a recognized risk factor for Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Because specific camel exposures associated with MERS-CoV seropositivity are not fully understood, we investigated worker–camel interactions and MERS-CoV seroprevalence. We assessed worker seroprevalence in 2 slaughterhouses and 1 live-animal market in Abu Dhabi, United Arab Emirates, during 2014–2017 and administered an epidemiologic survey in 2016 and 2017. Across 3 sampling rounds during 2014–2017, we sampled 100–235 workers, and 6%–19% were seropositive for MERS-CoV at each sampling round. One (1.4%) of 70 seronegative workers tested at multiple rounds seroconverted. On multivariable analyses, working as a camel salesman, handling live camels or their waste, and having diabetes were associated with seropositivity among all workers, whereas handling live camels and either administering medications or cleaning equipment was associated with seropositivity among market workers. Characterization of high-risk exposures is critical for implementation of preventive measures.

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