OTTAWA -- Health and security workers at airports and other key sites might refuse to work during a bird flu outbreak, complicating efforts to handle such a crisis, a Canadian government intelligence report warns.

The report says the entire country would probably experience "shortages of everything from fresh food and health supplies" due to worker sickness and fear of public exposure, the Canadian Press news agency reported Thursday.

The prospect of front-line staff at border points and airports staying home is among the worrisome scenarios flagged by analysts bracing for a possible flu pandemic.

The news agency told The Associated Press that it obtained the federal Transport Department report under Canada's Access to Information Act.

The assessment was completed in late last year was distributed to federal security and transportation officials as well as select U.S. government and private-sector personnel.

The World Health Organization has warned of a serious possibility of a bird flu pandemic. The virus has been spreading rapidly in birds throughout Europe, the Middle East, Africa and Asia, stirring fears that it could someday mutate into a form easily transmissible between humans.

Anti-viral drugs, which may blunt the severity of illness, would be given to airport, port and ground transportation officials on an urgent basis, the report said.

"When vaccines eventually become available, these officers would again need priority inoculations to ensure that they can carry out their tasks without fear of contracting the disease," the report says.

Because vaccines would not be available for months after the pandemic emerged, many quarantine officers and security officials, such as airport passenger screeners, might refuse to work, knowing that they would be exposed "to higher risk of infection and death," the report said.

A major disruption, or even temporary collapse, of Canada's transportation system could lead to widespread shortages of essential products, including food, soap, medicines and fuel, making recovery more difficult.