Qatar experience on One Health approach for middle-east respiratory syndrome coronavirus, 2012-2017: A viewpoint.

The emergence of the Middle East Respiratory Syndrome Corona Virus (MERS-CoV) in the Middle East in 2012 was associated with an overwhelming uncertainty about its epidemiological and clinical characteristics. Once dromedary camels (Camelus dromedarius) was found to be the natural reservoir of the virus, the public health systems across the Arabian Peninsula encountered an unprecedented pressure to control its transmission. This view point describes how the One Health approach was used in Qatar to manage the MERS-CoV outbreak during the period 2012-2017. One Health focuses on the association between the human, animals and environment sectors for total health and wellbeing of these three sectors. To manage the MERS outbreak in Qatar through a One Health approach, the Qatar National Outbreak Control Taskforce (OCT) was reactivated in November 2012. The animal health sector was invited to join the OCT. Later on, technical expertise was requested from the WHO, FAO, CDC, EMC, and PHE. Subsequently, a comprehensive One Health roadmap was delivered through leadership and coordination; surveillance and investigation; epidemiological studies and increase of local diagnostic capacity. The joint OCT, once trained had easy access to allocated resources and high risk areas to provide more evidence on the potential source of the virus and to investigate all reported cases within 24-48 h. Lack of sufficient technical guidance on veterinary surveillance and poor risk perception among the vulnerable population constituted major obstacles to maintain systematic One Health performance.

Occupational Exposure to Dromedaries and Risk for MERS-CoV Infection, Qatar, 2013-2014.

We determined the presence of neutralizing antibodies to Middle East respiratory syndrome coronavirus in persons in Qatar with and without dromedary contact. Antibodies were only detected in those with contact, suggesting dromedary exposure as a risk factor for infection. Findings also showed evidence for substantial underestimation of the infection in populations at risk in Qatar.

Reliable typing of MERS-CoV variants with a small genome fragment.

BACKGROUND: Middle East Respiratory Syndrome coronavirus (MERS-CoV) is an emerging pathogen that causes lower respiratory tract infection in humans. Camels are the likely animal source for zoonotic infection, although exact transmission modes remain to be determined. Human-to-human transmission occurs sporadically. The wide geographic distribution of MERS-CoV among dromedary camels and ongoing transmissions to humans provides concern for the evolution of a MERS-CoV variant with efficient human-to-human transmission capabilities. Phylogenetic analysis of MERS-CoV has occurred by analysis of full-length genomes or multiple concatenated genome fragments, which is time-consuming, costly and limited to high viral load samples. OBJECTIVE: To develop a simple, reliable MERS-CoV variant typing assay to facilitate monitoring of MERS-CoV diversity in animals and humans. STUDY DESIGN: Phylogenetic analysis of presently known full-length MERS-CoV genomes was performed to identify genomic regions with sufficient phylogenetic content to allow reliable MERS-CoV variant typing. RT-PCR assays targeting these regions were designed and optimized. RESULTS: A reverse-transcription PCR assay for MERS-CoV targeting a 615 bp spike fragment provides a phylogenetic clustering of MERS-CoV variants comparable to that of full-length genomes. The detection limit corresponds to a cycle treshold value of ∼ 35 with standard upE real time PCR assays on RNA isolated from MERS-CoV EMC. Nasal swabs from RT-PCR positive camels (Ct values 12.9-32.2) yielded reliable sequence information in 14 samples. CONCLUSIONS: We developed a simple, reliable MERS-CoV variant typing assay which is crucial in monitoring MERS-CoV circulation in real time with relatively little investment on location.

Immunogenicity of an adenoviral-based Middle East Respiratory Syndrome coronavirus vaccine in BALB/c mice.

A new type of coronavirus has been identified as the causative agent underlying Middle East Respiratory Syndrome (MERS). The MERS coronavirus (MERS-CoV) has spread in the Middle East, but cases originating in the Middle East have also occurred in the European Union and the USA. Eight hundred and thirty-seven cases of MERS-CoV infection have been confirmed to date, including 291 deaths. MERS-CoV has infected dromedary camel populations in the Middle East at high rates, representing an immediate source of human infection. The MERS-CoV spike (S) protein, a characteristic structural component of the viral envelope, is considered as a key target of vaccines against coronavirus infection. In an initial attempt to develop a MERS-CoV vaccine to ultimately target dromedary camels, we constructed two recombinant adenoviral vectors encoding the full-length MERS-CoV S protein (Ad5.MERS-S) and the S1 extracellular domain of S protein (Ad5.MERS-S1). BALB/c mice were immunized with both candidate vaccines intramuscularly and boosted three weeks later intranasally. All the vaccinated animals had antibody responses against spike protein, which neutralized MERS-CoV in vitro. These results show that an adenoviral-based vaccine can induce MERS-CoV-specific immune responses in mice and hold promise for the development of a preventive vaccine that targets the animal reservoir, which might be an effective measure to eliminate transmission of MERS-CoV to humans.

Isolation of MERS coronavirus from a dromedary camel, Qatar, 2014.

We obtained the full genome of Middle East respiratory syndrome coronavirus (MERS-CoV) from a camel in Qatar. This virus is highly similar to the human England/Qatar 1 virus isolated in 2012. The MERS-CoV from the camel efficiently replicated in human cells, providing further evidence for the zoonotic potential of MERS-CoV from camels.

Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation.

BACKGROUND: Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe lower respiratory tract infection in people. Previous studies suggested dromedary camels were a reservoir for this virus. We tested for the presence of MERS-CoV in dromedary camels from a farm in Qatar linked to two human cases of the infection in October, 2013. METHODS: We took nose swabs, rectal swabs, and blood samples from all camels on the Qatari farm. We tested swabs with RT-PCR, with amplification targeting the E gene (upE), nucleocapsid (N) gene, and open reading frame (ORF) 1a. PCR positive samples were tested by different MERS-CoV specific PCRs and obtained sequences were used for phylogentic analysis together with sequences from the linked human cases and other human cases. We tested serum samples from the camels for IgG immunofluorescence assay, protein microarray, and virus neutralisation assay. FINDINGS: We obtained samples from 14 camels on Oct 17, 2013. We detected MERS-CoV in nose swabs from three camels by three independent RT-PCRs and sequencing. The nucleotide sequence of an ORF1a fragment (940 nucleotides) and a 4·2 kb concatenated fragment were very similar to the MERS-CoV from two human cases on the same farm and a MERS-CoV isolate from Hafr-Al-Batin. Eight additional camel nose swabs were positive on one or more RT-PCRs, but could not be confirmed by sequencing. All camels had MERS-CoV spike-binding antibodies that correlated well with the presence of neutralising antibodies to MERS-CoV. INTERPRETATION: Our study provides virological confirmation of MERS-CoV in camels and suggests a recent outbreak affecting both human beings and camels. We cannot conclude whether the people on the farm were infected by the camels or vice versa, or if a third source was responsible. FUNDING: European Union projects EMPERIE (contract number 223498), ANTIGONE (contract number 278976), and the VIRGO consortium.