The Centers for Disease Control and health officials say that the 30-plus people who came down with a rare and deadly form of meningitis are linked by a steroid drug injection for back pain that may have been shipped to as many as 23 states. "The patients are thought to have been infected by a steroid drug contaminated with a fungus, Aspergillus," writes The New York Times's Denise Grady. And Aspergillus, the AP points out, is the source of this rare form of meningitis that's sent 18 people to the hospital in Tennessee and killed two in the state, as well as deaths in Virginia and Maryland. If there's a bright side, it's that this type of meningitis isn't contagious. "Eighteen of the cases are in Tennessee, where a Nashville clinic received the largest shipment of the steroid. The drug was made by a specialty pharmacy in Massachusetts that issued a recall last week," reports the AP. And the CDC, according to Grady, says that the drug—the treatment the drug is used in is called a lumbar epidural steroid injection, which the Mayo Clinic says is a temporary pain relief treatment for lower back pain—may have been shipped to as many as 23 states. And doctors are urging patients who have had the treatment in the past few months to go see a physician if they develop symptoms like headaches, fever, nausea, a loss of balance and slurred speech. In addition to Tennessee, Virginia and Maryland, cases have already been reported in North Carolina and Florida as well, and health officials according to both the AP and Grady are certain there will be more new cases in the coming days. "I’m afraid we’re going to see many more cases spread across the country," said Dr. William Schaffner, an infectious diseases expert at Vanderbilt University in Nashville told Grady.