Federal health officials have authority to detain or isolate any airline passenger suspected of harboring the avian flu virus, which scientists fear could mutate, making it easier for the virus to leap from person to person and quickly spread globally.
The Bush administration hopes quick action can contain any U.S. outbreak and has not ruled out travel restrictions.
Air travel helped spread the deadly Severe Acute Respiratory Syndrome, or SARS, virus around Asia and to Canada in 2003. SARS ended up killing around 800 people globally before it was contained.
SARS was harder to catch than the flu and, unlike influenza, only spread after patients began showing symptoms, but airlines and health officials are basing some bird flu preparations on the SARS experience.
The U.S. Centers for Disease Control and Prevention has increased the number of quarantine centers at big airports and land crossings from eight in 2003 to 18 now, partly due to the bird flu threat.
There are plans to expand to 25 centers, depending on resources and need, said Ram Koppaka, chief of the CDC's quarantine and border health division.
Pacific entry points, including Hawaii, Los Angeles, San Francisco and Seattle, are emphasized.
U.S. health officials are also working with airlines to review the cleaning of plane interiors and the handling of passengers with signs of viral illness.
But some airline workers and health experts see shortfalls in planning and recommend additional steps they say could save lives and help a financially fragile industry fly through a potential nightmare.
