The genomic sequence of MERS-CoV was closely related to bat CoVs HKU4 and HKU5 [18]. Bat CoVs that are evolutionarily closer to MERS-CoV, sharing ∼75% nucleotide sequence homology and using the same DPP4 receptor, were also identified [32]. Although bats are the evolutionary reservoir host and bat CoVs serve as the gene pool of MERS-CoV, humans acquire MERS-CoV from diseased dromedary camels, but not directly from bats. These camels are the natural reservoir host of MERS-CoV. MERS-CoVs isolated from dromedaries are identical to those found in humans. Experimental infection of dromedary camels with MERS-CoV results in mild disease, shedding large quantities of the virus from the upper respiratory tract [33]. In addition, other non-camelid domestic animals in close contact with infected camels, including sheep, goats, a cow, and donkeys, are also infected by MERS-CoV [34]. These domestic animals could also pose a risk to humans and should, therefore, be included in the MERS-CoV surveillance programme.