A group of European researchers have found evidence that camels can be infected with the MERS coronavirus.
It's a discovery that may help scientists tease out how people are contracting the new virus, which has infected at least 94 people and killed 46.
The researchers reported finding antibodies to MERS or a closely related coronavirus in the blood of camels from Oman on the Arabian Peninsula and also on the Canary Islands, part of Spain.
Antibodies are a sign these animals were infected in the past with the virus, but they are not proof that camels are infecting people.
Data needed on patients' contact with live camels
The scientists say more work is needed to see if people who have contracted the virus may have gotten it from contact with live camels or by consuming camel milk or meat.
Still, the World Health Organization's lead expert on the disease says this is the first strong clue of where to look for the virus and could help public health officials figure out ways to reduce the risk of future infection.
"We don't want to close our minds to other possibilities yet. But we certainly need to follow up and investigate this possible link further," says Dr. Anthony Mounts, the WHO's point person for MERS.
The study was published in the journal Lancet Infectious Diseases.
In addition to testing the blood of camels, the researchers tested blood samples of a variety of other animals, including other members of the same family as camels, to see if they had antibodies to the virus.
They didn't find evidence of prior infection in sheep, goats, cattle, llamas or alpacas. But those other animals were not from the Arabian Peninsula. They were from countries in Europe and in South America.
Senior author Dr. Marion Koopmans of the Dutch National Institute of Public Health says it would be important to test a variety of animals in the Middle Eastern countries where MERS infections have occurred.
Camels may infect other species
Koopmans says the findings don't rule out the possibility that MERS is infecting other species and that some other animal or animals may play a role in passing the virus to people.
"I think it shows that something — either MERS or something that looks very similar to it — has been going around in camels, and that that really needs to be looked at as a possible source. That's as far as we can go, I would say," she said in an interview.
"We shouldn't stop looking in other species based on this limited data that we have now."
To date all MERS infections have originated from four countries: Saudi Arabia, Jordan, Qatar and the United Arab Emirates.