Carnival and other major cruise lines are halting cruises to Mexico due to the swine flu outbreak.
Carnival said in a statement Monday that it will not be making any adjustments to its itineraries and that no guests on Carnival's ships have been reported having swine flu symptoms. By late Tuesday, they had decided to cancel calls on Mexican ports.
Carnival has cruises to Mexico from ports in Florida, Alabama, Louisiana, Texas and California.
Royal Caribbean, Norwegian and Celebrity cruise lines are following suit.
Customs officials at airports, seaports and border crossings are watching people entering U.S. territories for signs of the illness.