A bird flu pandemic remains a threat that the U.S. health care system must take seriously despite less frequent media coverage and the absence so far of human cases in the United States, experts warned.

John Bartlett, an infectious disease expert at John Hopkins University, said the decentralized U.S. health system will make it more difficult to get ready for a possible human pandemic of H5N1 avian virus — or anything else.

He disagreed with the suggestion that the bird flu threat has been overstated by the media.

“The number of cases in 2006 was more than it was in 2005, which is more than it was in 2004 … so it continues to go up in people,” he said in an interview.

“And it continues to be just as lethal as it was in the beginning,” Bartlett said at a conference aimed at helping U.S. hospital administrators prepare for a pandemic.

How big a threat? It’s hard to say, but as I’ve noted before, most of the preparations we make for an avian flu outbreak will also help with other possible epidemics. And the odds that we’ll have to deal with something nasty in the next decade or two seem fairly high.