The Department of Health and Human Services (HHS), which includes the U.S. Public Health Services, the Centers for Disease Control and Prevention (CDC) and other health agencies, has previously described itself as the "primary federal agency" in a national health emergency.

But at a meeting with reporters, Homeland Security Secretary Michael Chertoff said his department expects to have overall responsibility for managing a national pandemic response.

HHS would make decisions within its area of expertise, as would other federal, state and local agencies, he said.

Chertoff said that in the event of a pandemic, the government would depend heavily on the health expertise within HHS, "but we would manage the incident particularly with the view to make sure that all of the other pieces that could flow from the pandemic would be properly addressed."

Chertoff's statement and HHS pandemic planning documents suggest there is confusion over which government agency will have final authority over key decisions, such as who receives crucial drugs and vaccines and where health care resources are deployed.

Officials at HHS and the CDC did not respond to questions about Chertoff's assertions.

But public health officials and health care experts reacted with dismay.

"This is news to me," said Dr. George Hardy Jr., executive director of the Association of State and Territorial Health Officials, the professional organization for state health departments. "Clearly pandemics are public health issues. But certainly in today's climate, I would expect many parts of government — at the federal, state and local level —would be involved."

Health experts warned that placing Homeland Security above the country's health leadership threatened to repeat mistakes made during the fumbling response to the 2001 anthrax letter attacks, when public health expertise took a back seat to law enforcement concerns.

"They don't have the infrastructure at Homeland Security, or the technical expertise, to handle" a pandemic," said Dr. Georges(cq) Benjamin, executive director of the American Public Health Association, who was Maryland's health officer during the anthrax attacks.

"HHS and CDC need to be manning that process. To the extent it is coordinated with other federal agencies, Homeland Security, I am sure, will be in charge of intra-agency coordination. But at the end of the day, the command decisions for this ought to be made by public health practitioners."

The possibility that Homeland Security would lead a pandemic response drew quick negative reaction from emergency physicians, who expect their already overloaded departments to bear the worst burden in a mass outbreak.

"It's hard to imagine that Homeland Security, which has not worked on epidemics, could engage with an issue of this level of complexity, coming up to speed almost from scratch," said Dr. Arthur Kellermann, chief of emergency medicine at Emory University and a nationally recognized expert on emergency room overcrowding.

"Pandemic flu is a naturally occurring health threat of the first order, and the people who need to be at the center of that should be health care professionals first and foremost," he said.

In contrast, Dr. Michael Osterholm, a former Minnesota state epidemiologist who now directs the University of Minnesota Center for Infectious Disease Research and Policy, said he saw no conflict between the two federal agencies.

"It's not a problem," he said. "The secretary of HHS will be the key player in making the calls. There is no conflict between that and Homeland Security providing the coordination to make sure all the pieces work together."

Osterholm has been among the most vocal health officials in the country in warning of the implications of an influenza pandemic.

Flu experts at the CDC, the World Health Organization and other agencies have said that an A/H5N1 influenza strain circulating among wild and domestic fowl in Asia represents a serious threat to millions of people worldwide if it mutates into a disease that spreads among humans.

As of Aug. 5, 112 persons are known to have contracted the disease from infected fowl and 57 of them died, according to WHO.

European countries have begun scrambling to defend their poultry stocks against flu carried by migrating birds.

Animal-health agencies from the 25 European Union member countries plan to meet in Brussels Thursday to discuss the threat.

HHS has been under pressure from Congress for several months to finalize a response plan in case the deadly virus begins human-to-human transmission and Americans are endangered.

The plan was finalized at the beginning of this month and turned over to HHS Secretary Michael Leavitt, but it has not been made public.

A draft "Concept of Operations" document attached to the HHS plan, which was released last August, states: "HHS will be the primary federal agency responsible for public health and medical emergency planning, preparations, response and recovery" in a national health emergency.

The Department of Homeland Security asserts its authority to manage a pandemic response under a National Response Plan released in December that covers "incidents of national significance," including pandemics.

Both documents use very similar language to assert their authority.

HHS said it would take charge when "the resources of state, local or tribal public health and/or medical authorities are overwhelmed and HHS assistances has been requested by the appropriate authorities.

Homeland Security would assume authority when "the resources of state and local authorities are overwhelmed and federal assistances has been requested by the appropriate state and local authorities."

"The Department of Homeland Security has the responsibility for managing an incident," Chertoff said Tuesday.

As for the HHS plan, he said, "We are reviewing the plan now."

Russ Knocke, Chertoff's press spokesman, added that "at the management level, we would have the ball" in a flu pandemic.

"Homeland would be at the point from an incident management perspective, but HHS would be right there at our side providing invaluable expertise," Knocke said in a telephone interview.

Later, Knocke called back to say he had spoken with another official — whom he refused to identify — and sought to emphasize that "we will rely on our partners in the federal government to provide expertise" in dealing with a pandemic or other incident.