Middle East Respiratory Syndrome, a disease that has claimed close to 300 lives, could be airborne, able to spread from one person to another through the air, researchers say.
Scientists in Saudi Arabia report they've detected genetic evidence of the virus that causes the disease in the air in a barn which housed an infected camel.
The disease, which can pass from camels to humans, has been seen mostly in Saudi Arabia although instances have been reported in Europe, the United States and Asia in people who have returned from travel to the Middle East.
Although thought to pass to humans during close physical contact with camels or by consuming the meat or milk of the animals, the new finding suggests the disease may be transmittable through the air, the researchers say.
"The clear message here is that detection of airborne MERS-CoV molecules, which were 100 percent identical with the viral genomic sequence detected from a camel actively shedding the virus in the same barn on the same day, warrants further investigations and measures to prevent possible airborne transmission of this deadly virus," said study leader Esam Azhar, a medical virologist at King Abdulaziz University in Jeddah.
Airborne viruses are capable of spreading more widely and quickly through human populations than viruses that require direct contact between people or between people and animals, the researchers point out in a report on their findings in the journal mBio.
The air samples were taken from a barn housing camels in Jeddah belonging to a 43-year-old man who died from MERS.
Speculation that MERS might be airborne began following reports that some infected person had been in close but not direct contact with other MERS patients.
Workers in camel farms and slaughterhouses have been urged by the Saudi Health Ministry and the World Health Organization to take precautions including good hygiene, frequent washing of hands after handling animals, and the use of protective clothing.
Whether the virus can in fact be spread through the air will need further research, and the Saudi findings should not lead to jumping to conclusions, experts caution.
"What they say is that virus particles can be airborne, but it's premature to conclude that MERS is transmitted through aerosols," says Dr. Mark Denison, a professor at the Vanderbilt University School of Medicine.
"Do we still need to consider the possibility of airborne transmission?" he added. "Yes, of course."