Evidence is mounting that camels are the most likely intermediary in the transmission from bats to humans of the virus that causes Middle East Respiratory Syndrome.

While the virus itself has not been found in a camel yet, antibodies that react to it have been discovered in the blood of camels in Sudan, Egypt, Oman and the Canary Islands. The finding suggests that the animals had recovered from infection with the MERS virus or a close relative.

While many of the 114 confirmed MERS cases have had no contact with camels, it appears that the first confirmed or suspected cases in three separate clusters may have, and in two cases, the camels were observed to be ill.

According to the Saudi newspaper Asharq, a 38-year-old man from Batin, Saudi Arabia, who died of what was diagnosed as bacterial pneumonia was a camel dealer with at least one obviously sick camel. Later, other members of his family, including a mother, daughter and cousin, fell ill with what was diagnosed as MERS, and two died. They were part of a cluster of cases reported Sept. 7 by the World Health Organization.