If an influenza pandemic swept through the United States in the near future, tens of thousands would probably die and the economy could be hobbled as millions fell ill.

A Utah infectious diseases expert said Tuesday that the nation is poorly equipped to battle a flu outbreak like the one that shook the world in 1918, killing 40 million across the globe. Among the biggest obstacles is the lack of an adequate stockpile of antivirals, said Andrew Pavia, a professor of pediatrics at the University of Utah School of Medicine.

"A major pandemic is inevitable," said Pavia, who heads the Infectious Diseases Society of America's Pandemic Influenza Task Force. "Certainly we are overdue."

Some experts on infectious diseases are concerned the start of a pandemic could be brewing in Southeast Asia with the avian flu. This deadly strain has killed 46 people out of 69 confirmed cases in Cambodia, Thailand and Vietnam since January 2004, according to the World Health Organization.

Pavia emphasized there is no way to be sure that this could swell to pandemic levels, but said governments should act sooner rather than later.

Members of Pavia's organization recently urged the federal government to take several immediate steps to prepare for a pandemic. Experts have met with Sen. Orrin Hatch, R-Utah; Rep. Jim Matheson, D-Utah; Sen. Hillary Clinton, D-N.Y., and Sen. Bill Frist, R-Tenn.

Pavia, who is chief of the division of infectious diseases and geographic medicine, said the government needs to develop a better antiviral and vaccine stockpile. The current government supply of the antiviral Tamiflu would provide 7 million people with five-day doses. He said that number should be boosted to cover 150 million people in an emergency.

Laws are also needed to deal with liability concerns, he said. If a company rushes out vaccine doses during a declared national emergency, then the manufacturer should not be held liable for potential vaccine-related problems. Pavia said the same protection should be afforded to hospitals and health care workers vaccinating the public.

The third immediate key would be to require all health care workers to be vaccinated unless they had a religious or medical objection, he said. Most years, only about half of all health care workers are vaccinated.

A health care worker infected with the flu can spread the virus to more patients. To cut down on the spread of disease, and to set an example for others to follow, health care workers should have to be vaccinated, Pavia said.

Other longer-term goals set forth by Pavia's committee: Improve public education; entice drug makers to get into the vaccine business; enhance how various federal agencies, such as the Food and Drug Administration, respond; and improve coordination and communication among various groups mobilized for a pandemic response.

"We haven't done enough to get ready for the next pandemic," Pavia said.

Patrick Luedtke, deputy state epidemiologist with the Utah Department of Health, said a pandemic is certainly a concern for the state. In the 1918 flu pandemic, which some researchers say may have started in birds before jumping to humans, 675,000 people in the United States died and millions became sick. A disease outbreak of such proportion can wreak havoc on daily life in a society.

"Airplanes don't fly, garbage doesn't get picked up," he said.

Utah is reviewing its recently developed public health response plan, which is designed to treat patients and limit the spread of the disease.

State health officials are also working with the Utah Department of Food and Agriculture on a plan to respond to an outbreak of the flu in pigs or chickens. There is a chance that an animal version of the flu could be transmitted to people.

According to the Centers for Disease Control and Prevention, humans can contract the virus through contact with infected poultry or contaminated surfaces. To date, the virus has infected relatively few people and has rarely spread from person to person, the CDC states. The strain of the flu the CDC is worried about has not appeared in humans in the United States.

A pandemic could begin if a strain of the virus becomes easily transmissible from person to person, according to the CDC.

Utah's third major area of planning involves the surge capacities for the state's 43 hospitals.

"We expect many, many people to be sick at the same time" in the event of a pandemic, Luedtke said.

glavine@sltrib.com