Lab Update 41 – The BioFire® FilmArray® Meningitis/Encephalitis (ME) Panel

April 2023
Ampath | ampath.co.za

Overview

Central nervous system (CNS) infections carry high morbidity and mortality. Rapid identification of pathogens is crucial to:

• Improve patient outcomes
• Guide infection control measures
• Support early targeted therapy

The BioFire® Meningitis/Encephalitis (ME) Panel is a syndromic molecular test that detects 14 of the most common CNS pathogens with a rapid turnaround time.

Pathogens Detected by the BioFire® ME Panel

✅ Bacterial Pathogens

• Escherichia coli K1
• Haemophilus influenzae
• Listeria monocytogenes
• Neisseria meningitidis
• Streptococcus agalactiae (Group B Streptococcus)
• Streptococcus pneumoniae

✅ Viral Pathogens

• Herpes simplex virus 1 (HSV-1)
• Herpes simplex virus 2 (HSV-2)
• Varicella zoster virus (VZV)
• Cytomegalovirus (CMV)
• Human herpesvirus 6 (HHV-6)
• Enterovirus
• Human parechovirus

✅ Fungal Pathogen

• Cryptococcus species (C. neoformans / C. gattii)

Clinical Details

• Indication: Suspected meningitis or encephalitis
• Specimen: Cerebrospinal fluid (CSF)
• Mnemonic: CSFPCR
• Turnaround time: 6 hours (from time of lab receipt)

Advantages of the BioFire® ME Panel

• Rapid results
• Early initiation of appropriate therapy
• Enhances infection control
• Supports antimicrobial stewardship
• May detect pathogens even after antibiotics have been started

Limitations and Considerations

• Possible false positives, especially for Streptococcus pneumoniae and Haemophilus influenzae
  • Often linked to contamination from nasopharyngeal flora
  • Emphasises need for sterile CSF collection with PPE (including surgical mask)
• CMV and HHV-6 results may be hard to interpret
  • These viruses can reside latently in brain tissue or leukocytes
  • A positive result may not indicate active disease
  • Interpretation requires clinical correlation and immune status review
  • Consider viral quantification in CSF when appropriate
• False negatives may occur due to:
  • Presence of inhibitors
  • Low pathogen load (below detection threshold)
  • Pathogens not included in the panel (e.g. Mycobacterium tuberculosis, arboviruses)
• This panel is not suitable for healthcare-associated ventriculitis or meningitis

Best Practice Recommendations

• Always request additional CSF studies:
  • Cell count
  • Biochemistry
  • Microscopy
  • Culture and sensitivity (MCS)
  • Cryptococcal antigen
• In suspected herpes simplex virus (HSV) encephalitis:
  • If HSV is negative on the panel but clinical suspicion remains high:
    • Continue acyclovir treatment
    • Repeat HSV PCR after 72 hours

📌 For test cost or reimbursement queries, contact your local Ampath representative.