Dr. Julie Gerberding, the director of the Centers for Disease Control and Prevention, resigned. Dr. Gerberding, the first woman to direct the agency, announced her decision to resign via e-mail message to employees of the centers on Friday.

Her resignation was accepted by President-elect Barack Obama and it will take effect on the exact same day when the 44th President of the United States takes office – January 20.

However, Gerberding knew it was highly probable that she would leave her post after the Bush administration leaves office and she actually said that in a November e-mail message to staff members. Some colleagues said that, although she did not say anything publicly, Dr. Gerberding has hoped to be allowed to keep her post even after the new administration takes office.

The Bush administration requested resignation letters from several senior-level officials as a part of the transition process. Dr. Gerberding, who directed the Centers for Disease Control and Prevention for six years and through a world of bioterrorism fears caused by the September 11 attacks, was among those senior-level officials.

Dr. Gerberdig, 53, was appointed director of the CDC in July 2002. Now, after her resignation was accepted, her critics and supporters are talking and debating about her legacy.

Dr. Gerberding was and still is criticized mainly for sacrificing science for politics and focusing the research on what the Bush administration needed on issues such as the global warming. She was harshly criticized in 2007 for allegedly letting the Bush administration censor her congressional testimony on climate change. Among the parts deleted from her statement, one said that the global warming will cause “catastrophic weather events” such as heat waves, hurricanes and flooding.

“In the last eight years, across the board in government, politics has been trumping science,” said Jeff Levi, executive director of the Trust for America’s Health.

Meanwhile, backers are defending Dr. Gerberding for managing to keep the agency above political problems and expanding the focus of the research on bioterrorism, fighting AIDS on a global scale and responding to national health threats.

The Centers for Disease Control and Prevention investigates disease outbreaks, researches the cause and prevalence of health problems, and promotes illness prevention efforts. In 2007, the agency was designated by Harris Poll as the most efficient government agency.

Dr. Gerberdig is also director of the Agency for Toxic Substances and Disease Registry. The ATSDR and the CDC have a combined budget of approximately $9 billion and more than 14,000 employees.

Dr. Gerberdig, a former infectious diseases specialist at the University of California, San Francisco, receives a total compensation of $202,200.