Instructions for Clinicians Regarding Diagnostic Testing and Specimen Shipping for Central Nervous System and Parameningeal Infections

October 14, 2012 4:30 PM EDT

The pathogens involved in this cluster of infections are still under investigation. Thorough and rapid diagnostic evaluation is essential to identify pathogens causing infections in individual patients who received epidural injections of potentially contaminated steroid products from the New England Compounding Center, and may have implications for the nature of and duration of antimicrobial therapy.

The following algorithm has been developed to help guide clinicians in their diagnostic evaluation. These instructions are meant to supplement routine laboratory and microbiologic tests deemed necessary by the clinical team and should not replace existing diagnostic protocol.

Cerebrospinal fluid (CSF)

• When possible, collect a large volume of cerebrospinal fluid (CSF), ideally using a different site than was used for the epidural injection.
• Obtain routine gram stain and bacterial cultures, including aerobic and anaerobic. The priority for remaining CSF specimens is fungal culture, conducted at the local hospital or state lab. When possible, submit a large volume of CSF (minimum 10mL) for fungal culture.
• Remaining CSF may be sent to CDC for PCR. The minimum volume should be 1 mL; 5 mL is preferred. Samples sent to CDC should be unspun samples or freshly collected, unadulterated samples. If only a small volume can be obtained for CDC and the patient meets the case definition, send what you can.
• CSF should be sent only on patients with CSF results showing >5 white blood cells (use traumatic tap correction for WBC), regardless of glucose or protein levels.
• Specifically for the work-up of possible fungal pathogens:
  • Attempt to obtain larger volume of CSF to culture for fungi from intraventricular shunts/drains if patient presents with these.
• All cultures should be incubated for at least 2 weeks prior to discarding.

Other tests

• In addition to routine blood cultures, consider obtaining fungal blood cultures.
• Other potentially infected fluid collections should be sampled (e.g., aspiration of epidural abscess) and sent for microbiologic testing as described above for CSF specimens (including fungal smear).

Tissue specimens (including post-mortem specimens)

• Any relevant tissue specimens sent for histopathology should be stained and reviewed for infectious agents, including fungi (silver stain).
• Save specimens to send to state health departments and CDC for further evaluation. If fresh tissue can be saved, freeze at -70⁰C.
• Send available autopsy specimens to CDC for further evaluation. See attached guidance for specimen collection and processing.

Specimen shipping information

• Contact the State Health Department and State Public Health Laboratory to coordinate shipment of specimens to CDC for further testing.