Medical Microbiology is a tradition at The Johns Hopkins Hospital. William Henry Welch, the father of American Pathology, was the original Johns Hopkins Hospital microbiologist and a pioneer in the application of culture of bacteria for diagnosis of infections. The current division has offered state-of-the-art infectious disease diagnoses and consultative services for the clinical staff and physicians of the hospital since 1969.

In the 1970s, faculty provided expert diagnosis and treatment of fungal infections at a time when fungi were just being recognized as emerging threats to compromised patients. In 1989, the molecular revolution entered our laboratories, with nucleic acid probes and polymerase chain reaction used for rapid, sensitive detection and diagnosis of disease.

Today, with faculty internationally known for research and test development in diverse areas, the division is at the forefront of infectious disease diagnosis, consultation, and patient management. The laboratory is directed by Karen Carroll, M.D.