Muscat: Nasal and eye swab tests for camels in Oman found five out of 76 samples positive for Middle East respiratory syndrome coronavirus (MERS-CoV), and genetic sequencing showed that they were closely related to human viruses in the region, findings published by Eurosurveillance, a European peer-reviewed scientific journal, claimed.
This study was funded by the University of Veterinary Medicine, Vienna and was carried out in close cooperation with various ministries in the Sultanate.
The findings, reported in middle of this week by Eurosurveillance, add more evidence of zoonotic transmission and hint that dromedary camels could be the direct reservoirs.
The researchers also noted high viral loads in the swabs, building a case for respiratory transmission.
The group collected samples from 76 dromedary camels across Oman in December 2013. The animals were different ages, breeds, and belonged to both genders.
The investigators conducted two MERS-CoV reverse transcription quantitative polymerase chain reaction (RT-qPCR) tests on the samples, and retested the ones that were positive. They used gene sequences from the positive samples to perform a phylogenetic analysis.
The five positive samples from the Omani camels were identical to each other and highly similar to those from camel samples from Qatar and Egypt.
Compared the sequences
When the team compared the sequences with other camel samples and 33 human MERS-CoV sequences, they found that the camel sequences clustered independently from each other but with human MERS-CoV sequences from the same geographic area.
For example, the Omani camel sequence clustered closely with genes from human samples from the neighbouring United Arab Emirates, and researchers saw a similar connection between the animal and human Qatari sequences.
The authors said a high infectious dose through very close contact with a camel might trigger human infections and that the respiratory route might be the most likely route of transmission.
Since the first documented cases in spring 2012, MERS has sickened at least 339 people in Saudi Arabia alone and killed nearly a third of them, according to the country's Ministry of Health.
A recent surge in reported cases — including 26 new ones this past weekend — has fanned concerns that the outbreak might be shifting into a more dangerous phase.
Egypt became the latest of five countries — including Malaysia, the Philippines, Greece and Yemen — to confirm its first cases in April, all in travellers from the Gulf.
Though, a large number of people suspected of carrying MERS infection have been tested in Oman no positive cases have been recorded this year, according to a senior Ministry of Health (MoH) official.
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