There have been so many articles written recently about the outbreak of fungal meningitis secondary to spinal injections with a steroid that I thought I should make a few clarifying remarks. Most of what I say here is taken from the Morbidity and Mortality Weekly Report, or MMWR, published by the Center for Disease Control. Their statement is contained in their early release dated October 12, 2012, and their website is http://www.cdc.gov/mmwr.
Steroids (in this case methylprednisolone) can be used to relieve the inflammation of swollen nerves and joints, and are often given by injection epidurally (that is, near or into the spinal canal) to relieve the pain caused by sciatica or other neuritis. This can break the cycle of pain causing muscle spasm which in turn can pinch the nerve that travels through the muscle and perpetuate the pain. There have been various studies of the efficacy and permanence of the relief caused by this treatment, but a discussion of that is outside the scope of this blog.
The potential problem with steroid injections lies in the fact that it suppresses inflammation in part by suppressing the local release and local action of white blood cells. So if the steroid solution itself is contaminated with bacteria or fungi, you are not only inserting a pathogen into a very susceptible region of the body but you are also directly inhibiting the body's response to and elimination of the pathogen. In the recent epidemic, the contaminant was a fungus.
Now fungi reproduce vary slowly, so it can take weeks for the implanted infection to manifest itself. (In the recent outbreak the time between injection and the development of symptoms ranged from 1 to 42 days.) Because fungi reproduce slowly, the time necessary to treat fungal infections is measured in months, not in days or weeks, since most antifungals work by attacking fungal DNA after it has uncoiled to reproduce. And because fungi have sterol compounds in their cell membranes, ordinary antibiotics cannot penetrate the cell and therefore do not work. In addition, because the two-drug combination suggested by the CDC to treat fungal meningitis has serious side-effects, one does not give prophylactic antifungals as a rule.
Fungal meningitis is not contagious, and there has been no record of people-to-people spread. The contamination occurred at the factory where the steroid was compounded. For various legal reasons, such compounding facilities are NOT under FDA control, and therefore the production process is neither inspected nor sampled for absence of contamination by the federal government. A recall process has been instituted by the Massachusetts manufacturer under the auspices of the CDC, and over 90% of the patients who received injections from the contaminated lots have been reached and notified with the assistance of the local Boards of Health. IMHO, this does not mean that one should avoid epidural steroid injections, but it would be prudent to make sure that the supplier was "reputable", i.e. the drug came from a drug company whose name you recognized, since they would have much more to lose if their product were found to be unsafe.