The World Health Organization (WHO) says swine flu has now spread to 73 countries, with 139 deaths from the disease since it was first detected in April.
The latest WHO figures, released Monday, show more than 25,000 people have been infected with the swine influenza A-H1N1 worldwide.
The United States tops the list with more than 13,000 cases -- followed by Mexico, with more than 5,700. Most of the deaths from swine flu occurred in Mexico.
The WHO has said it is closer to declaring a pandemic because the infection appears to be taking hold outside North America.
The mayor of the southern U.S. city of New Orleans has been placed under quarantine in China after a fellow passenger on his flight to the country exhibited flu-like symptoms. Mayor Ray Nagin, his wife, and one member of his staff are now being held in Shanghai.
Nagin's office said Sunday the three were quarantined as a precaution. It says no one in Nagin's party has displayed symptoms of the flu.
Nagin traveled to China to discuss economic development opportunities, and is scheduled to travel on to Australia.