She's not an MD and there's no indication she worked in infectious disease research. If you read her resume, she at most worked as a researcher at Rochester for five years, from 1989 to 1994, before moving on to various positions (non-research) at Kansas State for sixteen years before moving to Northern Illinois to teach biology in 2010:
"Freeman earned a bachelor's degree in 1981, then a master's degree and a doctor of veterinary medicine in 1986, from Cornell University. She went on to earn a doctor of philosophy at The Ohio State University in 1989, and subsequently worked as a postdoctoral fellow and research scientist at the University of Rochester School of Medicine. "