Some of these dangerous infections are epidural abscesses: pockets of fungus growing inside the spine. Others are arachnoiditis, a deeper and more serious infection. Both kinds of infection can be crippling or fatal. A few of these infections were seen at the beginning of the outbreak. Now many more cases are popping up.
In some cases, these infections are the first signs of disease in people who received fungus-contaminated spinal steroid injections, says CDC fungal disease expert Tom M. Chiller, MD.
Many of the spine infections are in people who seemed to be recovering from life-threatening fungal meningitis.
"Some of these people were called in, diagnosed with meningitis, and treated. Their meningitis symptoms were improving," Chiller says. But then these patients reported pain in specific parts of the spine. Imaging studies showed they had these pockets of infection.
"We don't have a good handle on why that is," Chiller says. "This is an unprecedented event, injecting fungus into the [inside of the spine], and the disease is manifesting in many ways."
Fungal Epidural Abscess Symptoms
Nearly all the people who received the contaminated injections already were suffering severe back pain. That makes it hard to tell whether their old symptoms are coming back, or whether the pain is from a fungal infection.
In Michigan, which has the highest number of fungal meningitis cases, there have been 61 cases of meningitis and 44 cases of epidural abscess. But Tennessee, which has the second highest number of fungal meningitis cases, has not yet had any reports of epidural abscess.
Chiller says that anyone who received one of the tainted injections should see a doctor at the first sign of new back pain. He says their doctors should be ready to order tests of the spine whenever patients report these symptoms.
It's not clear how long the threat of fungal infections will hang over people who received the injections.
"The further out we get from the last injection of the contaminated lots of steroids, the lower people's risk for new infections," Chiller says. "We are getting further and further away from the exposures. We will see fewer and fewer people develop infections. But with fungal infections, incubation periods can be a long time, maybe months."
Fungal Epidural Abscess Treatment
Treatment of fungal epidural abscesses usually means surgery to drain pus and remove dead tissue, and months of treatment with antifungal drugs.
"The whole fungal infection arena is challenging," Chiller says. "Especially these mold infections, which can be slow-growing and hard to eradicate and require long treatment courses."
As of today, the CDC has been notified of 409 cases of fungal meningitis or other spine-related infections. Ten people have developed joint infections. Thirty people have died from the contaminated injections linked to the New England Compounding Center.