Clinical Significance of Positive Results of the BioFire Cerebrospinal Fluid FilmArray Meningitis/Encephalitis Panel at a Tertiary Medical Center in the United States

A successful diagnostic case of Varicella zoster virus pneumonia by a Film Array assay for meningitis/encephalitis

Introduction

Although varicella zoster virus (VZV) infection is generally considered self-limiting and shows a favorable outcome, herpes zoster (HZ) can cause several complications such as neurological pain or meningitis, which lowers the patients' quality of life. HZ rarely manifests VZV pneumonia, resulting in a poor prognosis with a high mortality rate of 10-30 % if requiring a mechanical ventilation. Here, we present a rare successfully managed case of VZV pneumonia.

Case presentation

A 90-year-old man with a medical history of angina pectoris, prostate cancer, dementia, and brain infarction was diagnosed with pneumonia and was admitted to our institute. Four days before the admission, he had visited our outpatient clinic, where he had received anti-herpes therapy due to HZ on the right limb. Although TAZ/PIPC was started empirically, his respiratory status deteriorated. On day 3, we performed a Film Array Meningitis/Encephalitis (ME) PCR panel on a sputum specimen and VZV was identified. Thus, he was diagnosed as having VZV pneumonia and antiviral therapy with acyclovir was started. Since the patient's condition was improved, the antiviral therapy was ended on day 18. Despite that his VZV pneumonia was successfully cured, he passed away due to old age on day 63.

Conclusion

Due to poor medical conditions, some elderly patients cannot tolerate bronchoalveolar lavage fluid for diagnosing VZV pneumonia. Film Array ME panel on sputum specimen is a useful method to the diagnosis of VZV pneumonia.

Comparison of positive BioFire FilmArray meningitis/encephalitis (ME) panels, CSF cultures, CSF parameters, clinical presentation and in-patient mortality among patients with bacterial and fungal meningitis

The BioFire FilmArray meningitis/encephalitis panel (MEP) was brought to the University of Kentucky in 2016 to aid in the identification of community-acquired meningitis and encephalitis (ME). This panel has shown variable performance with some institutions showing high sensitivity and specificity for many pathogens but others seeing false positives during clinical use. We evaluated the panel's performance using retrospective chart review of patients at the University of Kentucky from October 2016 to September 2022, including 7,551 MEP results. Cerebrospinal fluid (CSF) samples with positive results for bacterial and fungal pathogens were compared with CSF and blood cultures, other laboratory parameters, and clinical presentations, to classify MEP results as true positive (TP), likely TP, or false positive (FP). Of 132 patients with positive bacterial or fungal MEP results, 48.9% of bacterial and 88.9% of cryptococcal analytes were classified as TP. The positive predictive value (PPV) varied by organism, with the highest being Listeria monocytogenes and Neisseria meningitidis. One-third of the FP results were Streptococcus agalactiae. Among patients with likely TP, 75.7% (28 out of 37) received oral or IV antibiotics before blood or CSF culture. MEP was 100% specific compared to culture. The PPV based on pathogen ranged from 78.6% to 100%. Interestingly, 27.4% (29 out of 106) cases (excluding FPs) would have no pathogen definitively identified if MEP had not been used. This study highlights the utility of MEP in rapidly diagnosing ME, particularly in patients pretreated with antibiotics. It also emphasizes the importance of correlating MEP results with clinical assessments and other diagnostic tests to assure accuracy.

IMPORTANCE

This study compares the performance of the meningitis/encephalitis panel (MEP) in detecting bacterial and fungal pathogens with cerebrospinal fluid cultures and other parameters. Almost half of bacterial analytes of MEP had positive cerebrospinal fluid (CSF) or blood cultures; the remaining 42% of bacterial analytes were correlated with clinical presentation and other CSF parameters. 27.4% (29 out of 106) cases would not have had a pathogen definitively identified if the MEP had not been used. This study highlights the importance of using MEP as a diagnostic tool, especially in patients who have already received antibiotics, where traditional culture-based methods may not be diagnostic. This research underscores the use of MEP in improving the speed of diagnosing meningitis. However, it emphasizes that MEP can produce false positive results in some patients. It is therefore necessary to interpret MEP results together with clinical assessments and other diagnostic tests to ensure the most accurate diagnosis.

Evaluation of the QIAstat-Dx Meningitis/Encephalitis Panel, a multiplex PCR platform for the detection of community-acquired meningoencephalitis

Rapid identification of the causative pathogens of central nervous system infections is essential for providing appropriate management and improving patient outcomes. The performance of QIAstat-Dx Meningitis/Encephalitis (ME) Panel-a multiplex PCR testing platform-in detecting pathogens implicated in meningitis and/or encephalitis was evaluated using BioFire FilmArray ME Panel as a comparator method. This multicenter study analyzed 585 retrospective residual cerebrospinal fluid specimens and 367 contrived specimens. The QIAstat-Dx ME Panel showed positive percent agreement (PPA) values of 100% for Neisseria meningitidis, Streptococcus agalactiae, Escherichia coli K1, Listeria monocytogenes, and Cryptococcus gattii/neoformans on clinical samples compared to the BioFire FilmArray ME Panel. The PPA values observed for Haemophilus influenzae and Streptococcus pneumoniae were 80% and 88.24%, respectively. Negative percent agreement (NPA) values were >99.0% for each of the six bacterial targets and one fungal target tested with clinical samples. One viral target, herpes simplex virus 1, exhibited a PPA value of 100.0%, while the remaining viral targets-human parechovirus, herpes simplex virus 2, human herpes virus 6, and varicella zoster virus-were >90.0%, with the exception of enterovirus, which had a PPA value of 77.8%. The QIAstat-Dx ME Panel detected five true-positive and four true-negative cases compared to BioFire FilmArray ME Panel. The NPA values for all viral pathogens were >99.0%. Overall, the QIAstat-Dx ME Panel showed comparable performance to the BioFire FilmArray ME Panel as a rapid diagnostic tool for community-acquired meningitis and encephalitis.

Severe meningoencephalitis: epidemiology and outcomes

PURPOSE OF REVIEW

This article aims to provide an updated review on the epidemiology and outcomes of severe meningoencephalitis.

RECENT FINDINGS

Meningoencephalitis is a critical medical condition characterized by inflammation in both the meninges and brain parenchyma. Bacterial, viral, or fungal infections are common causes, although noninfectious factors, such as autoimmune causes, can also contribute. In patients requiring intensive care, meningoencephalitis is associated with a severe prognosis, including mortality rates ranging from 11 to 25% and functional disability in 15-25% of survivors. Recent multicenter studies have identified several parameters linked to poor outcomes, including older age, immunocompromised status, focal neurologic signs, abnormal brain imaging, and delayed administration of antimicrobials. The use of new multiplex PCR techniques for diagnosis has generated debate based on recent data. Investigation is still needed to determine the effectiveness of adjunctive therapies, including seizure prophylaxis, and adjunctive steroids for nonbacterial causes.

SUMMARY

Recent multicenter studies have enhanced our understanding of the current epidemiology and outcomes of severe meningoencephalitis in adult patients.

The experience of using FilmArray Meningitis/Encephalitis Panel for the diagnosis of meningitis and encephalitis in pediatric patients

BACKGROUND/PURPOSE

Central nervous system infections can cause severe complications and even death in children. Early diagnosis of the causative pathogen can guide appropriate treatment and improve outcomes. The BioFire® FilmArray® Meningitis/Encephalitis Panel (FA-ME) is a multiplex polymerase chain reaction (PCR) assay targeting 14 pathogens. We aimed to examine FA-ME performance compared with conventional assays and its effect on antimicrobial usage.

METHODS

We prospectively enrolled 55 pediatric patients with suspected meningitis or encephalitis and simultaneously performed FA-ME and conventional assays. Sixty-three hospitalized patients with CNS infection before implementing FA-ME were considered controls. We compared the FA-ME results with conventional assays and the empiric antimicrobial usage and hospital stay between the two study groups.

RESULTS

Nine patients (16.4%) tested positive by FA-ME, four were bacterial, and five were viral. Three additional pathogens were detected by conventional assays: Enterococcus faecalis, Leptospira, and herpes simplex virus type 2. In the control group, two bacterial pathogens were detected by CSF culture and four viral pathogens by single PCRs. Compared with the control group, the FA-ME group had a shorter time for pathogen detection, but there were no significant differences in pathogen detection rate, duration of empiric antimicrobial therapy, and length of hospital stay.

CONCLUSION

Although no significant difference was found in empiric antimicrobial duration and length of stay between patients tested with FA-ME and conventional assays, FA-ME had the advantage of a shorter detection time and early exclusion of potential causative pathogens. The FA-ME results should be interpreted carefully based on the clinical presentation.

Herpesvirus-Associated Encephalitis: an Update

Purpose of Review

Recent Findings

Summary

Impact of Implementing the Cerebrospinal Fluid (CSF) FilmArray Meningitis/Encephalitis Panel on Duration of Intravenous Acyclovir Treatment

Background

Herpes Simplex Virus-1 is the most common cause of sporadic encephalitis worldwide and requires prompt antiviral treatment. Traditionally, Herpes Simplex Virus-1 (HSV-1) cerebrospinal fluid (CSF) testing is conducted using standalone PCR. The BioFire CSF FilmArray Meningitis/Encephalitis Panel (BioFire ME Panel) was introduced in 2015 at our institution providing an alternative method of HSV-1 CSF testing. This study assesses the impact of the BioFire ME panel on duration of intravenous acyclovir treatment.

Methods

A retrospective review of electronic medical records between 2010 and 2019 was performed. Information on intravenous acyclovir treatment and HSV-1 CSF testing were collected and analyzed. Our descriptive analysis included Mann-Whitney tests, two proportion Z-tests, and logistic regression.

Results

Our CSF HSV-1 negative cohort included 524 BioFire patients (125 pediatric, 399 adult) and 287 standalone PCR patients (115 pediatric, 172 adult). Across both pediatric and adult groups, patients who were tested for HSV-1 with the BioFire ME panel had shorter average (SD) durations of intravenous acyclovir treatment [pediatric: 2.00 (5.71) days; adult: 3.26 (6.59) days] compared to patients tested with standalone PCR [pediatric: 4.83 (8.62) days; adult: 4.93 (8.46) days] (P <0.001). Time from lumbar puncture collection to HSV-1 results was additionally faster on average for the BioFire ME panel than the standalone PCR (P <0.001).

Conclusions

The implementation of the BioFire ME panel shortened CSF HSV-1 PCR result time and intravenous acyclovir duration. The shortened treatment and testing times from the BioFire ME panel implementation may reduce hospital treatment costs and unnecessary use of antiviral treatments.

FilmArray® Meningoencephalitis panel in the diagnosis of central nervous system infections: stewardship and cost analysis in a paediatric hospital in Chile

BACKGROUND

Central nervous system (CNS) infection has been an ongoing concern in paediatrics. The FilmArray® Meningoencephalitis (FAME) panel has greater sensitivity in identifying the aetiology of CNS infections. This study's objective was to compare the aetiological identification and hospitalization costs among patients with suspected CNS infection before and after the use of FAME.

METHODS

An analytical observational study was carried out using a retrospective cohort for the pre-intervention (pre-FAME use) period and a prospective cohort for the post-intervention (post-FAME use) period in children with suspected CNS infection.

RESULTS

A total of 409 CSF samples were analysed, 297 pre-intervention and 112 post-intervention. In the pre-intervention period, a total of 85.5% of patients required hospitalization, and in the post-intervention period 92.7% required hospitalization (p < 0.05). Median of ICU days was significantly lower in the post-intervention period than it was in the pre-intervention period. The overall positivity was 9.4 and 26.8%, respectively (p < 0.001). At ages 6 months and below, we found an increase in overall positivity from 2.6 to 28.1%, along with an increased detection of viral agents, S. agalactiae, S. pneumoniae, and N. meningitidis. The use of this diagnostic technology saved between $2916 and $12,240 USD in the cost of ICU bed-days. FAME use provided the opportunity for more accurate aetiological diagnosis of the infections and thus the provision of adequate appropriate treatment.

CONCLUSIONS

The cost/benefit ratio between FAME cost and ICU bed-day cost savings is favourable. Implementation of FAME in Chilean public hospitals saves public resources and improves the accuracy of aetiological diagnosis.