A fungal meningitis outbreak, brought on by black mold in contaminated injections for back pain, has taken the lives of 28 individuals and is affecting more than 300 people across 19 states. The infection is also responsible for multiple stroke cases, according to the United States Centers for Disease Control and Prevention.

“Never before has this particular fungus been found to cause meningitis,” The Associated Press reported. “It’s incredibly hard to diagnose, and to kill—requiring at least three months of a treatment that can cause hallucinations. There’s no good way to predict survival, or when it’s safe to stop treating, or exactly how to monitor those who fear the fungus may be festering silently in their bodies.”

“‘What we’re dealing with here is fundamentally different’ from a typical fungal infection, [fungal disease specialist at New York’s Albert Einstein College of Medicine Arturo Casadevall] said. ‘This is a bug that most of us don’t know much about’” (ibid.).

The black mold responsible for the outbreak is called Exserohilum rostratum, which is common in grass, plants and dirt. Until now, it has not been known to cause fungal meningitis.

Meningitis is an inflammation of the membranes that cover the brain and spinal cord. Symptoms include severe headaches, fever, neck stiffness, and slurred speech. Although fungal meningitis is not contagious, it is difficult to diagnose and treat due to the fact that symptoms can be slow to develop and the incubation period for the infection can be up to six weeks.

Dr. Robert Latham, chief of medicine at Saint Thomas Hospital in Nashville, Tennessee, told the Boston Globe that physicians were initially confused and frustrated because they could not identify the culprit for these life-threatening infections. They even compared it to AIDS before HIV was known as its cause.

“Doctors are beginning to detail in medical journals the first deaths in this outbreak, and the grim autopsy findings make clear that treating early is crucial, before the fungus becomes entrenched. In one case, a woman died in Maryland after the fungus pierced blood vessels in her brain, leading to severe damage.”