(ATLANTA) -- The U.S. Centers for Disease Control and Prevention reported two more deaths linked to the outbreak of fungal meningitis from steroid shots for back pain, bringing the total number of people who have died to 14.
The CDC also reported that 170 cases of the rare form of fungal meningitis have now been reported in 11 states.
The outbreak of aspergillus meningitis has been linked to an injectable steroid, called methylprednisolone acetate, made by the New England Compounding Center in Framingham, Mass. A sealed vial of the drug, obtained by the U.S. Food and Drug Administration, contained levels of fungus that were visible to the naked eye.
The New England Compounding Center has recalled all of its products and shut down operations, but health officials estimate that 13,000 people may have been exposed to the suspect steroid since May.
Forty-nine of the fungal meningitis cases -- six of them lethal -- have been reported in Tennessee. Cases have also been reported in Florida, Indiana, Maryland, Michigan, Minnesota, New Jersey, North Carolina, Ohio, Virginia and, most recently, Idaho.
[For a map of cases by state, click here.]
Seventy-six clinics in 23 states that received methylprednisolone acetate from the recalled lots have been instructed to notify all affected patients. The "potentially contaminated injections were given starting May 21, 2012," according to the U.S. Centers for Disease Control and Prevention.
For a full list of clinics receiving the recalled lots of spinal steroid injections, click here.
"If patients are concerned, they should contact their physician to find out if they received a medicine from one of these lots," said CDC's Dr. Benjamin Park, adding that most of the cases occurred in older adults who were healthy aside from back pain.
Meningitis affects the membranous lining of the brain and spinal cord. Early symptoms of fungal meningitis, such as headache, fever, dizziness, nausea, sensitivity to light, stiff neck, weakness or numbness, slurred speech and pain, redness or swelling at the injection site can take nearly a month to appear. Left untreated, the inflammatory disease can cause permanent neurological damage and death.
"Fungal meningitis in general is rare. But aspergillus meningitis -- the kind we're talking about here -- is super rare and very serious," said Dr. William Schaffner, president of the National Foundation for Infectious Diseases and chairman of preventive medicine at Vanderbilt University Medical Center in Nashville. "There's no such thing as mild aspergillus meningitis."
Fungal meningitis is diagnosed through a lumbar puncture, which draws cerebrospinal fluid from the spine that can be inspected for signs of the disease. Once detected, it can be treated with high doses of intravenous antifungal medications.
"Treatment could be prolonged, possibly on the order of months," said Park, adding that the IV treatment would require a hospital stay.
Unlike bacterial meningitis, fungal meningitis is not transmitted from person to person and only people who received the steroid injections are thought to be at risk.
Copyright 2012 ABC News Radio