May 2024—If anything keeps Arturo Casadevall, MD, PhD, lying awake at night, it’s the frogs. And the bats. Also, the patients (relatively few, at least for now) who are affected by invasive fungal diseases. Dr. Casadevall is a microbiologist and infectious diseases expert in the Johns Hopkins Division of Infectious Diseases, Department of Medicine, and the Bloomberg School of Public Health, where he’s a professor of medicine and chairs the Department of Molecular Microbiology and Immunology. In his waking hours, he looks deeply and broadly at the natural world and how the disturbing growth of fungal infections might impact the medical world. Though the arrows haven’t hit the bull’s-eye, they seem to be flying in that direction, says Dr. Casadevall, who has written widely on this topic, including “Immunity to Invasive Fungal Diseases.” In a recent interview with CAP TODAY, Dr. Casadevall spoke about how he and others in the field are thinking about how medicine might respond to this potential threat.