Thousands Exposed to Tainted Steroid, C.D.C. Says

About 13,000 people may have been exposed to the tainted steroid that has been linked to a growing outbreak of fungal meningitis, a spokesman for the Centers for Disease Control and Prevention said on Monday. The outbreak has killed 8 people and sickened 97 others in 23 states. More cases are expected. The figure, the first estimate of how many people were injected with any of the 17,676 doses shipped around the country, is based on reports from state health departments and clinics that used the drug, methylprednisolone acetate. It was injected near the spine to ease back and neck pain, a treatment that about five million people in the United States undergo every year.

The company that made the drug, the New England Compounding Center in Framingham, Mass., has shut down, surrendered its license and recalled all its products, not just the steroid.

The disease centers said that the company began shipping potentially contaminated lots of the drug on May 21, and that people who had the treatment for back pain — called a lumbar epidural steroid injection — after that date should seek medical attention if they develop symptoms like severe or worsening headache, fever, stiff neck, dizziness, weakness, sensitivity to light or loss of balance.

It is not known if all the vials of medicine in the implicated lots were contaminated with the disease-causing fungus, or if everyone exposed to it will become ill. Curtis Allen, the spokesman for the disease centers, predicted that most exposed people would not become sick.

But fungal meningitis can be severe and can cause strokes, and early treatment might save a patient’s life. Health officials say people who may have been exposed must be tracked down immediately so that those with symptoms can be treated as soon as possible. The treatment consists of an antifungal drug, either voriconazole or amphotericin B, and sometimes both. Months of treatment are needed. Because the drugs can have serious side effects, including kidney problems, they are given only to people who have symptoms, and are not used as a preventive measure in those who are not ill.

This type of meningitis is not contagious. Despite the treatment, some patients are in critical condition, doctors said.

Dr. John Jernigan, a medical epidemiologist at the disease centers, said, “This is a very rare form of meningitis and there is not a great deal of clinical experience with it.