Health officials in the U.S. have predicted, in the event of a bird flu pandemic, businesses and government can expect 40 percent of their employees to be absent during it's peak.
Michael Leavitt the Health and Human Services Secretary has called on all 50 states, as well as U.S. territories, to plan for a possible pandemic of influenza.
Health experts believe that an avian influenza is the most immediate threat but predict that an influenza pandemic of some sort is inevitable.
The HHS has projected that in a pandemic 92 million Americans will become sick and that as many as 2 million will die.
Schools will close, businesses will be disrupted and essential services may break down.
Co-ordinator of the HHS' plan, Dr. Bruce Gellin, says as many as 40 percent of workers could be out at any one time, including those who are ill, people caring for others and people who are just scared to go to work.
In view of that Leavitt says states and communities need to prepare plans as soon as possible.
At a meeting in Washington of state and local health and emergency officials, Leavitt said that they are going to organise a rally to engage, inform and motivate people who would be critical at local levels.
To date the H5N1 avian flu virus has infected 130 people in five Asian countries and killed 69 of them.
But it is spreading steadily among poultry flocks from China to Ukraine, and experts expect it will affect birds all around the world.
Scientists fear it may mutate into a form that could spread easily from person to person, which would cause a global epidemic that could kill tens of millions.
According to Leavitt, although political leaders understood and were acting on the threat, many local officials such as school administrators and business operators were not mobilized.
He expresses concern for example of the impact on the country if power plants lose 40 percent of their workers for a time or if truck drivers refuse to leave home.
Gellin says there will not be enough ventilators for everybody who will need them and medical care as may not be the same during a pandemic.
Apparently University of Minnesota public health expert Mike Osterholm, who advises the federal government, has already estimated that the United States only has 105,000 ventilators, 80,000 of which are being used at any one time.
It is known that the H5N1 virus has a 50 percent mortality rate, but no one knows how it will mutate and how that will affect its ability to be transmitted, to cause disease and to kill.
On a more optimistic note Gellin believes the death rate in an actual pandemic would be far less than 50 percent.
However some state health officers are very skeptical of the U.S. federal flu plan.
Dr. Donald Williamson, Alabama's state health officer, says that in the 2003 smallpox panic, U.S. health officials planned to vaccinate 500,000 health care and emergency workers against a potential biological attack, but only about 40,000 actually received the vaccine.
That, he says, seriously undermined credibility.
Dr. Susan Allan, state public health director for Oregon, said many doctors, nurses and health experts at that time simply did not believe there was a real threat from smallpox.
She says people feel there has been a different disease panic from one month to another for the past five years.
Many health experts feel the flu plan is too focused on drugs and vaccines and not enough on sanitation, equipment such as gloves and masks and the ability to treat patients outside of overburdened hospitals.