Researchers have said they found the first direct evidence that the potentially deadly Middle East respiratory virus, or MERS, jumps directly from camels to humans.
The virus has hit Saudi Arabia the hardest, killing 282 people out of 688 infected, according to the Saudi health ministry's latest figures.
MERS has been found elsewhere in the Middle East and in Europe, Asia and North America, brought by travellers who were infected in Saudi Arabia or the United Arab Emirates.