Rapid diagnosis is critical in managing central nervous system infections. Clinicians often rely on the BioFire FilmArray Meningitis/Encephalitis (FA/ME) Panel for quick pathogen identification. However, indiscriminate testing often leads to high costs and low positivity rates. Diagnostic stewardship in meningitis has emerged as a vital strategy to optimize these resources. Recent research suggests that using specific laboratory parameters can streamline testing without compromising patient safety.

Improving Efficiency with Diagnostic Stewardship in Meningitis

A recent retrospective study conducted at an Australian tertiary hospital evaluated over 700 patients. The study focused on optimizing the use of the FA/ME panel through a structured stewardship algorithm. Researchers found that the cerebrospinal fluid (CSF) white cell count (WCC) is a highly reliable predictor of test positivity. Specifically, a WCC threshold of >50 × 10⁶/L proved remarkably effective. By applying this threshold, the hospital could have doubled the panel’s positivity rate to nearly 30%.

Furthermore, implementing this stewardship approach significantly reduces healthcare expenditures. The study projected a decrease in annual costs from $23,302 to approximately $14,646. This reduction occurs by avoiding expensive multiplex testing in cases with low pre-test probability. Instead, specimens with lower WCC can undergo reflex testing using alternative, less costly viral multiplex PCRs. Importantly, this strategy detected all clinically significant infections in the study cohort.

Clinical Impact and Patient Outcomes

The benefits of optimized testing extend beyond cost savings. Positive FA/ME results are strongly associated with targeted antimicrobial therapy. Moreover, rapid results allow for shorter hospital stays for many patients. Consequently, clinicians can de-escalate broad-spectrum antibiotics earlier, which is a key goal of antimicrobial stewardship programs. Therefore, hospitals should consider integrating WCC thresholds into their diagnostic protocols for meningitis and encephalitis.

Frequently Asked Questions

What is the BioFire FilmArray ME Panel?

The BioFire ME Panel is a rapid multiplex PCR assay. It simultaneously detects 14 common pathogens, including bacteria, viruses, and yeast, that cause meningitis and encephalitis.

How does CSF white cell count help in testing?

A high white cell count in the cerebrospinal fluid often indicates an active infection. Using a threshold like 50 cells/µL helps identify cases where the multiplex panel is most likely to yield a positive, clinically relevant result.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or establish a doctor-patient relationship. Always consult a qualified healthcare professional for diagnosis and treatment. Refer to the latest local and national guidelines for clinical practice.

References

Ibrahim NH et al. Efficient use of the BioFire® FilmArray® Meningitis/Encephalitis Panel: a diagnostic stewardship approach. Intern Med J. 2026 Mar 13. doi: 10.1111/imj.70391. PMID: 41826261.

Leber AL, et al. Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens. J Clin Microbiol. 2016;54(9):2251-61.

Buchan BW, et al. Clinical Evaluation of a Multiplex PCR Panel for Causative Agents of Central Nervous System Infection. J Clin Microbiol. 2018;56(7):e00181-18.