WASHINGTON — Health officials confirmed Wednesday that bats in Saudi Arabia were the source of the mysterious virus that has sickened 96 people in the Middle East, killing 47 of them.

The outbreak of Middle East Respiratory Syndrome, or MERS, has been going on for 15 months, with most victims falling ill in Saudi Arabia and others growing sick after having traveled to the Middle East. In a study released Wednesday, an international team of doctors blamed coronavirus in bats for the human outbreak, but said that many questions remained, in part because a perfect match for the virus was found in only a single insect-eating bat out of about 100 Saudi bats tested. And since such bats do not normally bite people, drool on fruit or do other things that might transmit the disease to people, it was still unclear how the virus leapt to humans.

The bat is a Taphozous perforatus, or Egyptian tomb bat, which roosts in abandoned buildings, and the virus was found in a fecal sample.

So it is possible, said Dr. Jonathan H. Epstein, a veterinarian with the EcoHealth Alliance who helped trap the bats, that victims, like shepherds who might seek shelter in the buildings, picked it up by breathing in dried bat guano — similar to the way that Americans have been infected with hantavirus while sweeping up dried mouse droppings.