The nation's top public health agency has a new director. 

Secretary of  Health and Human Services Tommy Thompson announced that Dr. Julie Gerberding will be the first woman to head the Centers for Disease Control and Prevention. Gerberding, who was acting deputy director for the CDC, is an infectious diseases specialist and anthrax expert.

"Dr. Gerberding knows public health, she knows infectious diseases, and she knows bioterrorism preparedness," Thompson said at CDC's Atlanta headquarters Wednesday. "She brings the right mix of professional experience and leadership skills to ensure the CDC continues to meet the nation's public health needs."

Gerberding, 46, started up in 1998 with the CDC, where she worked on measures to protect health care workers exposed to viruses. Prior to that she worked at the University of California San Francisco, helping to develop programs to prevent infections in patients and health care providers.

"The country could not be better served," said Dr. Julius R. Krevans, chancellor emeritus at the university.

"She's somebody who has been able to withstand the pressure and take the heat and always use good science-based judgment to make decisions," said Dr. James Curran of Emory University, the CDC's former AIDS chief, who has known Gerberding for more than a decade.

The CDC has been under attack by some quarters that complain that it had free reign in the 1990s to pursue politically-correct studies on gun control, rather than focusing on more pressing issues like its primary mission of fighting disease. The CDC was also criticized by Congress for its initial clumsy reaction to anthrax attacks last fall, but Gerberding was credited with pulling together a coordinated response.

That type of organization and focused attention will come to the fore as the CDC takes on immediate challenges like preparing the nation for a potential bioterror strike, and working with CIA, FBI and officials at the proposed Homeland Security Department.

Former CDC director Jeffrey Koplan stepped down March 31, saying it was time to move on after more than three years in the job.

The Associated Press contributed to this report.