Updated

Chinese authorities have quarantined New Orleans Mayor Ray Nagin, his wife and a security guard in Shanghai after another traveler on their flight from New Jersey exhibited suspected swine flu symptoms.

Nagin's office said the three were quarantined in a hotel Sunday as a precaution and were exhibiting no flu symptoms.

"He's doing well. His spirits are fine," Nagin's spokeswoman Ceeon Quiett told The Associated Press on Monday in New Orleans. She did not know when the three might be released or whether they will be tested for the flu.

She said the quarantine was for passengers who sat near the traveler with flu-like symptoms but she did not know if anybody besides the Nagin trio was affected. Quiett also did not release the name of the airline, deferring to embassy officials.

The U.S. Consulate in Shanghai and local officials did not respond to questions Monday.

China has been imposing quarantines and temperature checks at airports throughout the country to prevent the virus from spreading. If the quarantined individuals display no flu symptoms, they are usually released in about seven days.

Last month, China quarantined a group of 21 students and three teachers from a Maryland private school for five days in a hotel. Officials feared the group from the Barrie School in Silver Spring was exposed to swine flu on their flight from San Francisco to Hong Kong.

The World Health Organization reported that, as of Monday morning, 73 countries had officially reported 25,288 cases of infection. Most of the cases have been mild, though 139 people have died.

Nagin's office said a passenger on the flight from Newark, N.J., had "signs and symptoms of an influenza-like illness suspected to be of the H1N1 subtype."

Three other city employees on the trip were not sitting close enough to the passenger to be quarantined, Quiett said. They were the deputy head of the press office, James Ross, city economic development director Ernest Gethers and Lisa Ponce de Leon, director of international affairs.

Quiett said Nagin has been in contact with city officials in New Orleans and that city business continues in his absence.

Nagin left Friday on an economic development trip through the eastern Pacific and had two meetings in Shanghai before getting the quarantine notice, Quiett said. Private interests were to pay for that leg of his trip, Quiett said, though she did not say who those interests were and said the cost was "not available to us."

Nagin was scheduled to travel next to Australia to speak at a conference on climate change and the global recession at the University of Sydney, but the status of those plans remained unclear Monday morning.

New Orleans' departing recovery director, Ed Blakely, was a professor at the university and among the conference's scheduled speakers. A spokeswoman for the university's United States Studies Centre has said Blakely is being made an "honorary" professor in urban policy at the center.

Nagin's schedule initially had him in Shanghai until Tuesday and then in Australia from Wednesday until Sunday. The mayor and his party were due to return to New Orleans June 15.