Atlanta ? Some U.S. hospitals already are struggling to deal with the current flu outbreak. But that is nothing compared to what would happen if a powerful new flu strain exploded into a worldwide flu outbreak, known as a pandemic.

Patients would overwhelm hospitals, and the overflow would have to be housed elsewhere, such as schools — which already would be closed. Nurses, already in short supply, could not possibly get to everyone. And there would be even fewer doctors and nurses once they, too, started getting sick.

There would not be enough antiviral drugs or ventilators to take care of the elderly, who are most at risk of dying from flu.

“Pandemic flu is a special challenge … it has a much greater potential for the disruption of the function of society,” said Dr. Jeffrey Duchin. As chief of communicable disease control, epidemiology and immunization for Seattle-King County’s public health department in Washington state, Duchin is one of the many health officials wrestling with the challenge.

“It’s arguably the most significant biological disaster that could ever afflict a community,” he said.

Many public health officials say the country needs to do much more to ready itself for such a disaster, and U.S. Health and Human Services Secretary Tommy Thompson said last week that work was under way on a national preparedness plan.

HHS expects $50 million from Congress for pandemic flu planning, including research into ways of speeding up flu vaccine manufacturing. The department will ask for $100 million more in fiscal year 2005.

“The world will be in deep trouble if the impending influenza pandemic strikes this week, this month or even this year,” wrote Drs. Robert Webster and Richard Webby, of the St. Jude Children’s Research Hospital infectious disease department, in an article last month in the journal Science. “The time for talking is truly over.”

In some ways, the country is better prepared than it was a few years ago. The Sept. 11, 2001, terrorist attacks jump-started health agency and government planning for everything from chemical spills to bioterrorism.

But much remains to be done.

Many hospitals have disaster plans that address pandemic flu, but they lack specifics, said James Bentley, senior vice president for strategic policy planning for the American Hospital Assn.

A pandemic likely would force hospitals to put overflow patients in their hallways or cafeterias, or even into other public facilities such as armories or school, Bentley said.

And only a quarter of state health departments have specific pandemic flu plans, according to a recent study.