A dozen people have been sickened and two have died after an outbreak of fungal meningitis tied to injections given at outpatient surgical centers in Tennessee and North Carolina, health officials said. At least 737 people who received lumbar epidural steroid injections between July 30 and Sept. 20 have been notified of the cluster of rare aspergillus meningitis infections, which attack the central nervous system, said Curtis Allen, a spokesman for the Centers for Disease Control and Prevention. Aspergillus is a mold present in the environment, and the meningitis is not related to the more common bacterial or viral types of meningitis. “The main thing is that it’s not transmissible person-to-person,” said Allen. Federal, state and local health officials are investigating the source of the outbreak. Eleven of the victims received injections at the Saint Thomas Outpatient Neurosurgery Center in Nashville. Another patient received an injection at an unidentified clinic in North Carolina. The Tennessee clinic was closed Sept. 20 and has been shuttered until further notice, officials said. The patients were older people, between the ages of 40 and 80, who were receiving the steroid injections as treatment for musculoskeletal disorders, said Woody McMillin, spokesman for the Tennessee Department of Health. Neither federal nor state health officials would identify the brand of epidural steroids given to the patients nor the manufacturer of the drugs. Asked whether the drugs themselves could have been contaminated, McMillin said that’s one possibility. “Right now, we’re not taking anything off the table,” he said. Erica Jefferson, a spokeswoman for the federal Food and Drug Administration, said that it’s too soon to speculate about that because the investigation is still “evolving.” Meningitis caused by aspergillus is very rare, according to the Journal of Microbiology. Symptoms often include a fever and headache that might be present for weeks before a diagnosis is made.