A leading AIDS researcher and proponent of medication-assisted therapy for addiction was appointed Wednesday March 21 2018 to oversee the Centers for Disease Control and Prevention. Dr. Robert R. Redfield is a professor at the University of Maryland School of Medicine in Baltimore and co-founder of the Institute for Human Virology. Dr. Redfield, 66, will replace Dr. Brenda Fitzgerald, who resigned in January after just six months on the job. Dr. Fitzgerald left amid criticism of her investments with her husband in tobacco and health care companies that posed potential conflicts of interest. A graduate of Georgetown University and its School of Medicine, Dr. Redfield did his residency at the Walter Reed Army Medical Center, then stayed on as a researcher in the military, focusing on AIDS. In 1996, he launched the virology institute with Dr. Robert C. Gallo, who developed the blood test for H.I.V., the human immunodeficiency virus. Dr. Redfield, 66, has longstanding ties to various government agencies. He served on two advisory panels for the National Institutes of Health from 2002 to 2006, when Mr. Azar was general counsel and then deputy secretary of the Department of Health and Human services. Dr. Redfield’s high profile on AIDS research and policy matters has made him a perennial candidate for the C.D.C. job. Medical careers run in Dr. Redfield’s family. Both his parents worked at the National Institutes of Health, and two of his children are doctors. His wife, Joy, is a nurse whom he met while they were delivering babies together.