GENEVA - The World Health Organization says it suspects U.S. swine flu patients may have transmitted the virus to others in the United States.
Confirmation would indicate the new flu strain is spreading beyond those travellers returning from Mexico. The global health agency says so far, most people confirmed with swine flu were infected in Mexico.
But WHO spokesman Gregory Hartl says the source of some infections in the United States, Canada and Britain is unclear.
Hartl told reporters in Geneva today that WHO suspects people are infecting others with the disease in other locations than Mexico.