Fungal Meningitis Outbreak and exposure to Aspergillus spores

by Al Franzblau on October 7, 2012

SEM Aspergillus mould producing spores (conidia) Scanning electron micrograph of <I>Aspergillus</I> producing spores, computer-coloured green. The picture shows an <I>Aspergillus</I> conidiophore with conidia (spores) budding off (tissues stained blue). <I>Aspergillus</I> is a genus of ascomycetes, some species of which cause aspergillosus or severe asthmatic reactions in humans; other species have industrial uses, e.g. in the processing of soybeans and the fermentation of sake.

SEM image of Aspergillus mould producing spores (conidia) Credit: David Gregory & Debbie Marshall, Wellcome Images

As of 2:00 PM today (Sunday, October 7) there were 91 reported cases of meningitis in 9 states, including 7 deaths according to the Centers for Disease Control and Prevention (CDC), all apparently related to use of an injectable steroid preparation used to treat back pain (see for instance New York Times, Oct 7).  All of the cases have an unusual form of infectious meningitis (a disease involving the meninges, or the tissue layer surrounding the brain and spinal cord) due to a fungus or mold.

The normally sterile drug, methylprednisolone acetate, has been found to be contaminated with fungal spores from the genus Aspergillus.  This is a commonly found mold and airborne exposure is ubiquitous in the indoor and outdoor environments – and usually does not lead to harm (see for example Baxter et al. 2005; Chew et al. 2003; Shelton et al. 2002).  Despite almost constant and widespread environmental exposure, this type of deep tissue infection with Aspergillus essentially never happens among persons with a normal immune system.  Inhaled Aspergillus spores are typically unable to penetrate beyond the lungs to cause harm; what sets the current outbreak apart is the direct delivery of the spores to the meninges, thus bypassing the body’s defense systems.

According to the CDC, fungal meningitis is not transmissible from person-to-person – there is no risk of ‘catching it’ from someone who has this disease. State medical and health authorities, and the Centers for Disease Control and Prevention, are attempting to have the remaining suspect drug recalled, and to notify all patients who may have received injections of the drug.

The contaminated drug has been traced to a single source, the New England Compounding Center, an independent drug compounding pharmacy.  Exactly how or why the contamination occurred in the manufacturing process is unclear.  But, questions have been raised concerning the regulatory oversight of such independent drug pharmacies, which may not be as stringent as oversight of major drug manufacturing facilities (New York Times, Oct 7).

For up to date information on the outbreak, see


Baxter DM, Perkins JL, McGhee CR, Seltzer JM.  A regional comparison of mold spore concentrations outdoors and inside “clean” and “mold contaminated” southern California Buildings.  J Occup Environ Med.  2005;2(1):8-18. DOI: 10.1080/15459620590897523  (Download PDF).

Chew GL, Rogers C, Burge HA, Muilenberg ML, Gold DR.  Dustborne and airborne fungal propagules represent a different spectrum of fungi with differing relations to home characteristics.  Allergy.  2003;58:13-20. DOI: j.1398-9995.2003.00013.x (Download PDF)

Shelton BG, Kirkland KH, Flander WD, Morris GK.  Profiles of airborne fungi in buildings and outdoor environments in the United States.  Applied Environ Microbiol.  2002;68(4):1743-1753. Full Text:

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