The United States Navy has called off a humanitarian mission to the South Pacific after one of its ships was hit by the swine flu outbreak.
The navy says a crew member on the USS Dubuque is ill with the H1N1 virus and 49 others have developed symptoms.
The other 370 crew members and staff have begun a 10-day course of the anti-viral drug Tamiflu.
Last week about 30 Marines on a Southern California military base were quarantined because of the swine flu virus. Four were eventually diagnosed with the strain.