MERS-CoV antibodies were found in camels across Africa and the Middle East, indicating that they had previously been infected with MERS-CoV or a closely related virus.
Researchers from three centers in the United States and two in Saudi Arabia conducted complete genetic sequences for MERS-CoV isolates generated from five camels, the results verified them identical to published sequences of human isolates.
Goats, cows, sheep, water buffalo, swine and wild birds have been tested for antibodies to MERS-CoV; none have yet been detected.
The findings above support the hypothesis that camels are a probable source of infection transfer to humans, while bats may be the ultimate reservoir of the virus. The high infectious dose would require very close contact between an infected camel and humans for instigation of human MERS-CoV infection by camels. It has been suggested the virus could infect humans by air, via camel milk or meat.