"All patients who may have received these medications need to be tracked down immediately," said Benjamin Park, medical officer at the CDC's mycotic-diseases branch. "It is possible that if patients with infection are identified soon and put on appropriate anti-fungal therapy, lives may be saved."
This type of meningitis is not contagious and can't be spread from person to person, Park said.
Infected patients have developed a variety of symptoms, which have set in one to four weeks after their injections. These include fever, a new or worsening headache, nausea and problems similar to those seen in a stroke.
CDC officials say anyone who had an epidural injection since July should contact a doctor if they have these symptoms, and also if they have a stiff neck, sensitivity to light, slurred speech or newly developed weakness in any part of the body.
Health inspectors found fungus in at least one sealed vial of the steroid at the company's facility, according to the Food and Drug Administration. At a press conference last week, officials said they found foreign material in other products as well, but had not yet had time to test what that material was.
The Massachusetts pharmacy has voluntarily shut down. The company has recalled the steroid, and the government urged doctors not to use any of the company's products.
The outbreak is already interrupting medical care for some patients.
Anders Cohen, chief of neurosurgery and spine surgery at the Brooklyn Hospital Center in New York, said he advises patients in pain to wait until the CDC's investigation is completed before getting steroid injections.
Steroid injections are an "extremely common" treatment for lower back pain, such as sciatica caused by a herniated disk, said William Blau, a professor of anesthesiology at the University of North Carolina's School of Medicine. "I'm guessing there are hundreds or thousands every day," he said.
Steroids decrease inflammation, which can ease pain. Injections are a mainstay of pain management, used for decades. They're a good alternative to narcotics for people with chronic pain because they are very safe, effective and pose no risk of addiction, said David Zvara, chair of anesthesiology at UNC-Chapel Hill.
The risk of complications is a fraction of 1 [percent], Blau said.