Cynthia L. Sears, MD, FIDSA, is an exemplary scientist who has made seminal contributions to the field of infectious diseases through her groundbreaking research, leadership roles with IDSA, editorial acumen and mentorship. A role model for scores of highly successful ID specialists, she has made invaluable advances in our understanding of the microbiota and its impact on colorectal cancer and treatment.
Dr. Sears is a professor of medicine and oncology at the Johns Hopkins University School of Medicine and a professor of molecular microbiology and immunology at the university’s Bloomberg School of Public Health. She also leads the Microbiome Program at the Bloomberg-Kimmel Institute for Cancer Immunotherapy at Johns Hopkins and is director of the Germ-Free Murine Facility.
Driven by a commitment to improving patient care and scientific investigation, she has conducted numerous studies on gut infections, including diarrhea, foodborne illnesses and Clostridioides difficile during her career. A seminal study she led, published in Science in 2018, established the connection between host microbiota and cancer.
Her work has changed the scientific perspective on the origins of colorectal carcinoma by elucidating the role of specific tumorigenic bacteria in the progression from gut colonization to malignancy. Dr. Sears has identified toxin-producing strains of Bacteroides fragilis, characterized the mechanisms of toxin action and revealed the interplay of these strains with other key members of the gut microbiota and mucosal immune responses in promoting colorectal carcinoma, in the context of host genetic susceptibility.
A global leader in microbiome research, she is co-principal investigator on the UK-CRUK Cancer Grand Challenges, a global initiative that identifies the toughest challenges in cancer research.
As a member of the IDSA Board of Directors from 2004 to 2007 and from 2010 to 2020, including serving as treasurer from 2010 to 2015 and as president in 2019, she led the Society’s efforts to advance national policy on antimicrobial resistance and stewardship and pandemic preparedness. She has served on or led several IDSA committees, groups and task forces. An associate editor of Clinical Infectious Diseases from 2000 to 2016, in 2022, she became editor-in-chief of The Journal of Infectious Diseases, a position she continues to hold.
Dr. Sears has authored more than 170 publications, worked on multiple funded grants and mentored dozens of junior faculty, postdoctoral fellows and students. She has been honored with induction into the American Association of Physicians and elected as a fellow of the American Association for the Advancement of Science. She has also received the Kimmel Cancer Center’s prestigious mentoring award.
A world-renowned physician-scientist, mentor, educator, editor and leader, Dr. Sears embodies all the virtues celebrated by the Alexander Fleming Award for Lifetime Achievement. The Society is proud to honor her with this award in 2025.