President Obama will announce that he has chosen Thomas R. Frieden, MD, the New York City health commissioner, as the next director of the Centers for Disease Control and Prevention, administration officials said. Frieden, an infectious disease specialist, has cut a high and sometimes contentious profile in his seven years as New York's health official commissioner. He led the crusade to ban smoking in restaurants and bars, pushed to make HIV testing a routine part of medical exams, and defended a program that passes out more than 35 million condoms a year. At the CDC, he will inherit a host of immediate and long-term problems.