A new report offers the strongest evidence yet that a mysterious Middle East virus spreads from camels to people.
Researchers studied the illness of a 44-year-old camel owner in Saudi Arabia, who died in November of Middle East respiratory syndrome, or MERS. Through repeated tests, they were able to show: the man and one camel were infected with the same virus; the camel got it first; and the man got sick after putting medicine on the animal's runny nose.
The virus had previously been detected in camels, and officials believe it had spread from camels to people in some MERS cases, though clear proof of that was lacking.
"Earlier work had different pieces of the puzzle that made this story likely. But in this small episode, all the pieces came together" to offer definitive evidence, said Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Nashville.
The new study was published online Wednesday by the New England Journal of Medicine.
MERS is a respiratory illness that begins with flu-like fever and cough but can lead to shortness of breath, pneumonia and death. Since it first appeared two years ago, roughly 800 illnesses have been reported to international health agencies, including about 300 deaths. Most cases have been in Saudi Arabia and neighboring nations. Those outside the region — including two in the United States — have been mostly people who had traveled from the Middle East.
Still unknown is how often camel-to-human spread occurs and whether other animals or environmental sources could be transmitting the virus. Health care workers and family members have gotten it after close contact with MERS patients.
The new report details the case of a man who owned nine camels and kept them in a barn in southwest Saudi Arabia. In October, four of his animals got sick. A week later, he developed flu-like symptoms. He was hospitalized in the city of Jeddah in early November, and died there two weeks later. The camels recovered.
rgy.? dc@? ` tures outside a cell's nucleus. Defects in the mitochondria's genetic code can result in diseases such as muscular dystrophy, heart problems and mental retardation.
The techniques involve removing the nucleus DNA from the egg of a prospective mother and inserting it into a donor egg, where the nucleus DNA has been removed. That can be done either before or after fertilization.
The resulting embryo would end up with the nucleus DNA from its parents but the mitochondrial DNA from the donor. Scientists say the DNA from the donor egg amounts to less than 1 percent of the resulting embryo's genes. But the change will be passed onto future generations, a major genetic modification that many scientists and ethicists have been loath to endorse.
Earlier this year, the U.S. Food and Drug Administration held a meeting to discuss the techniques and scientists warned it could take decades to determine if they are safe.