Mayor Ray Nagin, who traveled to China on an economic development trip, flew on a plane that carried a passenger being treated for symptoms suspected to be from the virus, commonly known as the swine flu virus, the mayor’s office said in a statement.

Nagin, his wife and a member of his security detail have been quarantined in Shanghai, China, though all three are symptom free, the statement said.

“The mayor is being treated with utmost courtesy by Chinese officials,” the statement said.

Ceeon Quiett, the mayor’s director of communications, told CNN that Nagin had been sitting beside a passenger who “exhibited the symptoms of H1N1,” but Nagin showed no signs of illness.

WASHINGTON – The strain of flu virus that is alarming the world is so new and poorly understood that it justifies the U.S. government’s multi-pronged efforts to fight it, President Barack Obama said Saturday.

Swine flu, or H1N1 flu as the government calls it, has caused only one confirmed U.S. death. But medical authorities fear it could become much worse, Obama said in his weekly radio and Internet address, and that’s why he has thrown substantial federal resources into the campaign against it.