GENEVA — A Saudi man who died from the MERS virus probably caught it after caring for one of his sick camels, the most conclusive evidence so far that the animals can infect humans.

The 44-year-old man died in November with Middle East respiratory syndrome, about a month after treating a dromedary camel with nasal discharge, researchers from King Abdulaziz University in Saudi Arabia wrote in the New England Journal of Medicine. Samples taken from both patient and camel found a genetically identical virus, the authors said.

Previous studies found the bug in camels from the Canary Islands to Ethiopia, along with signs that many of the people infected had contact with the animals. But there was no conclusive evidence of transmission until now.

“Camels may act as intermediate hosts that transmit the virus from its reservoir to humans,” the authors wrote. “The exact reservoir that maintains the virus in its ecologic niche has yet to be identified.”

The man in the study kept nine camels in a barn about 47 miles south of Jeddah, the authors wrote. The patient and three of his friends visited the camels daily. The owner fell ill about seven days after applying a topical medicine in the nose of one of the four sick camels, his friends told scientists. The friends, who had no direct contact with the animals’ secretions, remained free of the virus.

The man first developed fever, a runny nose and a cough, followed by severe shortness of breath that caused him to be hospitalized. He died two weeks later.

Saudi Arabia on Tuesday increased its estimate of the death toll from the virus to 282 from 190 and the total number of cases to 688 from 575 after a review of cases stretching back to 2012. The government also fired deputy health minister Ziad Memish, six weeks after relieving health minister Abdullah al- Rabeeah of his duties.

MERS first came to light when a 60-year-old Saudi man died with severe pneumonia and kidney failure in Jeddah in June 2012. Since then the virus has spread globally, with cases reported in Europe, Africa, Asia and the U.S. There’s no vaccine and no specific treatment.

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