The nation’s ongoing fungal meningitis outbreak has killed 30 and sickened 419 people so far, but the fungus responsible has never wrought such havoc before.
The fungus, Exserohilum rostratum, is a plant-eating generalist equipped with a spore-launching mechanism ideal for going airborne, is not an especially picky eater and, although it prefers grasses, will dine on many items—including humans.
But just how a pathogen typically associated with the great outdoors got into the three lots of injectable steroids prepared inside an admittedly filthy laboratory—and why only three lots—remains a puzzling mystery.
The errant fungus has been identified in lab samples from 52 of those affected and was similarly found growing in unopened vials of the steroid alleged to have caused the outbreak, according to the U.S. Centers for Disease Control and Prevention. A third recalled lot is still being tested. But E. rostratum is not a household name, even among mycologists.
Glenn Roberts, a retired medical mycologist, says that in his 40 years of experience at the Mayo Clinic in Rochester, Minn., he had seen only one case: a soft-tissue arm wound in an immunocompromised patient. He was shocked when he heard the identity of the pathogen in the epidemic that originated with the New England Compounding Center pharmacy in Framingham, Mass.