BEIJING -- They take their quarantines very, very seriously in China. They don't even allow phone calls.

The mayor of New Orleans, Ray Nagin, is under lockdown in a suburban Shanghai hotel after a passenger on his flight from the U.S. exhibited symptoms of swine flu -- and now his Chinese hosts are screening his calls "to keep him safe."

Nagin and his wife Seletha have been in quarantine since Sunday, along with a member of the mayor's executive protection team, after they had the misfortune of sitting within a few rows of a French student now confirmed ill with the A-H1N1 virus on their flight from the U.S.

Officials at the hotel where Nagin is quarantined, the Jinjiang Inn in Shanghai's Nanhui district, have refused even to pass on telephone messages without the permission of the city's Disease Control and Prevention Office. They, in turn, handed requests over to the municipal foreign affairs department, which yesterday claimed no knowledge of the case.

"We have to keep him safe," said a woman who said she was acting as a translator at the hotel.

Ceeon D. Quiett, Nagin's director of communications, said in a statement Sunday that the three were symptom-free and "being treated with utmost courtesy by Chinese officials." But she couldn't say how long they'll be forced to stay in the hotel, which is a designated city quarantine site. Quarantine measures in China typically last seven days.

Nagin had planned several days of trade-related meetings in China followed by a flight to Sydney, Australia, where he is to give a speech on climate change at a university summit.

China now has 80 confirmed cases of swine flu, including 10 in Shanghai. An Associated Press reporter was quarantined in the same hotel last month after his flight made a brief stopover in Mexico. Will Weissert described ample if greasy food, twice-daily temperature checks, limited English-language television and considerable boredom, which he said was his biggest inconvenience.