Rapid Diagnostic Tests for Meningitis and Encephalitis-BioFire

Elsberg Syndrome: A Case Report of a Novel Radiographic Presentation

Introduction: Elsberg syndrome (ES) presents with bowel and bladder dysfunction, resembling cauda equina syndrome, and is classified as a clinicoradiographic syndrome most commonly associated with HSV-2 reactivation. Most cases reveal smooth and continuous nerve enhancement on imaging. Case Description: We present a unique case of ES that presented as several nodular, ring enhancing soft tissue masses along the cauda equina. An 81-year-old woman presented with several weeks of sacral sensory impairment. MRI of the lumbar spine at presentation showed several nodular, ring enhancing soft tissue masses within the thecal sac along the cauda equina, concerning for leptomeningeal carcinomatosis from an unknown primary source. Cerebrospinal fluid (CSF) analysis was notable for lymphocyte predominant pleocytosis and protein elevation, which was nonspecific but suggestive of leptomeningeal carcinomatosis. CSF rapid meningitis panel was positive for HSV2 which was confirmed on HSV2 PCR. The patient was briefly on on acyclovir and was stopped due to lack of meningioencephalitis symptoms. Malignancy workup with cytological analysis and systemic imaging were negative. Given the absence of malignancy and positive HSV2 PCR, the patient was diagnosed with HSV-2 sacral radiculitis and subsequently treated with a full course of intravenous acyclovir with gradual clinical and radiographic improvement. Discussion: Ring-enhancing lesions along the cauda equina are most suggestive of LC. Our case highlights an as of yet unreported presentation of ES which may be valuable for neurologists to be aware of as to avoid any potential diagnostic dilemma, minimize unnecessary and costly testing, and not delay effective treatment.

Novel and Rapid Diagnostics for Common Infections in the Critically Ill Patient

There are several novel platforms that enhance detection of pathogens that cause common infections in the intensive care unit. These platforms have a sample to answer time of a few hours, are often higher yield than culture, and have the potential to improve antibiotic stewardship.

Global, regional, and national burden of meningitis and its aetiologies, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Although meningitis is largely preventable, it still causes hundreds of thousands of deaths globally each year. WHO set ambitious goals to reduce meningitis cases by 2030, and assessing trends in the global meningitis burden can help track progress and identify gaps in achieving these goals. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we aimed to assess incident cases and deaths due to acute infectious meningitis by aetiology and age from 1990 to 2019, for 204 countries and territories.

METHODS

We modelled meningitis mortality using vital registration, verbal autopsy, sample-based vital registration, and mortality surveillance data. Meningitis morbidity was modelled with a Bayesian compartmental model, using data from the published literature identified by a systematic review, as well as surveillance data, inpatient hospital admissions, health insurance claims, and cause-specific meningitis mortality estimates. For aetiology estimation, data from multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature studies were analysed by use of a network analysis model to estimate the proportion of meningitis deaths and cases attributable to the following aetiologies: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococcus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Staphylococcus aureus, viruses, and a residual other pathogen category.

FINDINGS

In 2019, there were an estimated 236 000 deaths (95% uncertainty interval [UI] 204 000-277 000) and 2·51 million (2·11-2·99) incident cases due to meningitis globally. The burden was greatest in children younger than 5 years, with 112 000 deaths (87 400-145 000) and 1·28 million incident cases (0·947-1·71) in 2019. Age-standardised mortality rates decreased from 7·5 (6·6-8·4) per 100 000 population in 1990 to 3·3 (2·8-3·9) per 100 000 population in 2019. The highest proportion of total all-age meningitis deaths in 2019 was attributable to S pneumoniae (18·1% [17·1-19·2]), followed by N meningitidis (13·6% [12·7-14·4]) and K pneumoniae (12·2% [10·2-14·3]). Between 1990 and 2019, H influenzae showed the largest reduction in the number of deaths among children younger than 5 years (76·5% [69·5-81·8]), followed by N meningitidis (72·3% [64·4-78·5]) and viruses (58·2% [47·1-67·3]).

INTERPRETATION

Substantial progress has been made in reducing meningitis mortality over the past three decades. However, more meningitis-related deaths might be prevented by quickly scaling up immunisation and expanding access to health services. Further reduction in the global meningitis burden should be possible through low-cost multivalent vaccines, increased access to accurate and rapid diagnostic assays, enhanced surveillance, and early treatment.

FUNDING

Bill & Melinda Gates Foundation.

Evaluation of the Novel CE-IVD-Marked Multiplex PCR QIAstat-Dx Meningitis/Encephalitis Panel

Central nervous system (CNS) infections such as meningitis and encephalitis are life-threatening conditions that demand hospital care and prompt identification of the causative agent. Since 2015, there has been only one CE-IVD-marked rapid multiplexed diagnostic assay in cassette format for bacterial and viral detection from cerebrospinal fluid (CSF): the BioFire FilmArray meningitis/encephalitis (ME) panel. In the beginning of 2022, Qiagen introduced the QIAstat-Dx meningitis/encephalitis panel. It is a CE-IVD-marked multiplex PCR cassette test intended for the identification of suspected infectious meningitis, encephalitis, or meningoencephalitis caused by bacterial, viral, or fungal pathogens. In this study, we evaluated patient and quality control samples using the QIAstat-Dx meningitis/encephalitis panel and compared the results to those of the BioFire FilmArray meningitis/encephalitis panel and reference methods (current routine analysis methods in our laboratory, PCR, or cultivation). The combined positive percent agreement between the two panel assays was 100%, and the negative percent agreement was 94%. We further compared specifically herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) dilution series using six commercial herpesvirus assays, including the two cassette tests. The results suggested that real-time PCR methods (with separate extraction) were the most sensitive methods. When comparing the cassette tests, the BioFire FilmArray meningitis/encephalitis panel produced more positive results than the QIAstat-Dx meningitis/encephalitis panel in the herpesvirus analyses. IMPORTANCE The diagnosis of infectious meningitis and encephalitis relies mostly on specific PCR and culturing methods, but commercial syndromic panel assays are bringing a change in diagnostics. With multiplexed analysis, the identification of the pathogen is potentially faster, and less sample material is needed. The novel QIAstat-Dx meningitis/encephalitis panel assay is intended for the rapid identification of pathogens from cerebrospinal fluid for suspected central nervous system (CNS) infection, which is a life-threatening condition and difficult to diagnose. We studied the performance of this panel assay using patient samples and dilution series of selected viruses. The evaluation data for this novel meningitis/encephalitis panel assay are useful for other clinical laboratories and organizations using or considering using this test.

Novel and Rapid Diagnostics for Common Infections in the Critically Ill Patient

There are several novel platforms that enhance detection of pathogens that cause common infections in the intensive care unit. These platforms have a sample to answer time of a few hours, are often higher yield than culture, and have the potential to improve antibiotic stewardship.

How do we reduce acyclovir overuse? Impact of FilmArray meningitis/encephalitis panel tests for pediatric patients

BACKGROUND

Few Japanese hospitals can perform in-house cerebrospinal fluid (CSF) polymerase chain reaction (PCR) to screen for herpes simplex virus, leading to patients being administered acyclovir (ACV) for several days. The FilmArray Meningitis/Encephalitis Panel (ME Panel) is a multiplex PCR test that can identify 14 major pathogens within 1 h. We aimed to investigate the efficacy of the ME Panel in children admitted with central nervous system infections in Japan.

METHODS

We conducted a single-center, quasi-experimental study. The ME panel was introduced in April 2020. We outsourced the CSF samples to a laboratory during the pre-intervention period (April 2016 to March 2020) and performed the ME panel at our hospital during the post-intervention period (April 2020 to December 2021). Duration and dose of ACV and antibiotic use, length of stay (LOS) in the pediatric intensive care unit (PICU), and total LOS after testing were compared using the Mann-Whitney U test.

RESULTS

The number of cases in the pre- and post-intervention periods was 67 and 22 cases, respectively. The median duration of ACV decreased significantly from 6 days to 0 day (p < 0.001), and the median dose of ACV use decreased significantly from 14 vials to 0 vial (p < 0.001). No significant differences were noted in the total duration and dose of antibiotic use, LOS in PICU, and the total LOS after testing.

CONCLUSION

The introduction of ME panel may contribute to appropriate ACV use; however, there was no significant change in the duration and dose of antibiotic use or LOS.

Evaluation of Discordant Results Between FilmArray Meningitis/Encephalitis Panel and Conventional Testing in Pediatric Patients: A Multisite Retrospective Cohort Study

BACKGROUND

The FilmArray Meningitis/Encephalitis panel (MEP) has an 11% false-positive and 2.2% false-negative rate compared with conventional testing. We describe clinical characteristics, treatment decisions, and outcomes in children with discordant results between MEP and conventional testing.

METHODS

We conducted a multisite review of patients ≤ 18 years with suspected central nervous system infection and positive results by MEP or conventional testing (cerebrospinal fluid [CSF] culture, herpes simplex virus [HSV] polymerase chain reaction (PCR), and enterovirus [EV] PCR). Descriptive results are provided for patients with discordant results. Comparison between group 1 (MEP and CSF culture positive) and group 2 (MEP positive, CSF culture negative, or showing a different pathogen) was made by Mann-Whitney test for continuous and Fisher's test for categorical variables.

RESULTS

A total of 355 patients had at least one pathogen identified. More than half of patients with bacterial pathogens identified that are included in the MEP had discordant results (30/52; 58%). There were 28 samples with bacterial pathogen identified on MEP only, 1 with different bacterial pathogens on MEP and culture, and 1 with Escherichia coli identified on CSF culture only. Patients in group 1 were more likely to have CSF pleocytosis, elevated CSF protein, and decreased CSF glucose than group 2 (P < .05). Two patients were HSV positive by MEP while HSV negative by PCR. Ten patients had discordant results between MEP and EV PCR.

CONCLUSIONS

Discordant results between MEP and conventional testing are common. Treatment decisions based on a positive MEP should be made in the appropriate clinical context.

Group B Streptococcal Neonatal Meningitis

Neonatal bacterial meningitis is a devastating disease, associated with high mortality and neurological disability, in both developed and developing countries. Streptococcus agalactiae, commonly referred to as group B Streptococcus (GBS), remains the most common bacterial cause of meningitis among infants younger than 90 days. Maternal colonization with GBS in the gastrointestinal and/or genitourinary tracts is the primary risk factor for neonatal invasive disease. Despite prophylactic intrapartum antibiotic administration to colonized women and improved neonatal intensive care, the incidence and morbidity associated with GBS meningitis have not declined since the 1970s. Among meningitis survivors, a significant number suffer from complex neurological or neuropsychiatric sequelae, implying that the pathophysiology and pathogenic mechanisms leading to brain injury and devastating outcomes are not yet fully understood. It is imperative to develop new therapeutic and neuroprotective approaches aiming at protecting the developing brain. In this review, we provide updated clinical information regarding the understanding of neonatal GBS meningitis, including epidemiology, diagnosis, management, and human evidence of the disease's underlying mechanisms. Finally, we explore the experimental models used to study GBS meningitis and discuss their clinical and physiologic relevance to the complexities of human disease.

Biofire FilmArray Meningitis/Encephalitis panel for the aetiological diagnosis of central nervous system infections: A systematic review and diagnostic test accuracy meta-analysis

BACKGROUND

The FilmArray Meningitis/Encephalitis(FA/ME) panel brings benefits in clinical practice, but its diagnostic test accuracy (DTA) remains unclear. We aimed to determine the DTA of FA/ME for the aetiological diagnostic in patients with suspected central nervous system(CNS) infection.

METHODS

We performed a systematic review with DTA meta-analysis (PROSPERO: CRD42020139285). We searched Embase, Medline (Ovid), and Web of Science from inception until September 1st, 2021. We assessed the study-level risk of bias with the QUADAS-2 tool and applied the GRADE approach to assess the certainty of the synthesised evidence. We included studies that simultaneously measured the reference test (CSF/blood culture for bacteria, and specific polymerase chain reaction for viruses) and the FA/ME in patients with suspected CNS infection. We performed random-effects bivariate meta-analysis models of combined sensitivity and specificity using CSF/blood cultures(reference test 1) and a final diagnosis adjudication based on clinical/laboratory criteria (reference test 2).

FINDINGS

We included 19 studies (11,351 participants). For all bacteria with reference test 1 (16 studies/6183 patients) sensitivity was estimated at 89·5% (95%CI 81·1-94·4), and specificity at 97·4% (95%CI 94-98·9). With reference test 2 (15 studies/5,524 patients), sensitivity was estimated at 92·1%(95%CI 86·8-95·3) and specificity at 99.2(95%CI 98·3-99·6) For herpes simplex virus-2(HSV-2), enteroviruses, and Varicella-Zoster virus (VZV), we obtained sensitivities between 75·5 and 93·8%, and specificities above 99% (reference test 1). Certainty of the evidence was low.

INTERPRETATION

FA/ME may have acceptable-to-high sensitivities and high specificities for identifying bacteria, especially for S.pneumoniae, and viruses, especially for HSV-2, and enteroviruses. Sensitivities for L.monocytogenes, H.influenzae, E.coli, and HSV-1 were suboptimal.

FUNDING

None.

Impact of a Multiplex Polymerase Chain Reaction Panel on Duration of Empiric Antibiotic Therapy in Suspected Bacterial Meningitis

Background

Multiplex polymerase chain reaction (PCR) panels allow for rapid detection or exclusion of pathogens causing meningitis and encephalitis (ME). The clinical impact of rapid multiplex PCR ME panel results on the duration of empiric antibiotic therapy is not well characterized.

Methods

We performed a retrospective prepost study at our institution that evaluated the clinical impact of a multiplex PCR ME panel among adults with suspected bacterial meningitis who received empiric antibiotic therapy and underwent lumbar puncture in the emergency department. The primary outcome was the duration of empiric antibiotic therapy.

Results

The positive pathogen detection rates were similar between pre- and post-multiplex PCR ME panel periods (17.5%, 24 of 137 vs 20.3%, 14 of 69, respectively). The median duration of empiric antibiotic therapy was significantly reduced in the post-multiplex PCR ME panel period compared with the pre-multiplex PCR ME panel period (34.7 vs 12.3 hours, P = .01). At any point in time, 46% more patients in the post-multiplex PCR ME panel period had empiric antibiotic therapy discontinued or de-escalated compared with the pre-multiplex PCR ME panel period (sex- and immunosuppressant use-adjusted hazard ratio 1.46, P = .01). The median hospital length of stay was shorter in the post-multiplex PCR ME panel period (3 vs 4 days, P = .03).

Conclusions

The implementation of the multiplex PCR ME panel for bacterial meningitis reduced the duration of empiric antibiotic therapy and possibly hospital length of stay compared with traditional microbiological testing methods.

Evaluation and Management of Well-Appearing Febrile Infants 8 to 60 Days Old

This guideline addresses the evaluation and management of well-appearing, term infants, 8 to 60 days of age, with fever ≥38.0°C. Exclusions are noted. After a commissioned evidence-based review by the Agency for Healthcare Research and Quality, an additional extensive and ongoing review of the literature, and supplemental data from published, peer-reviewed studies provided by active investigators, 21 key action statements were derived. For each key action statement, the quality of evidence and benefit-harm relationship were assessed and graded to determine the strength of recommendations. When appropriate, parents' values and preferences should be incorporated as part of shared decision-making. For diagnostic testing, the committee has attempted to develop numbers needed to test, and for antimicrobial administration, the committee provided numbers needed to treat. Three algorithms summarize the recommendations for infants 8 to 21 days of age, 22 to 28 days of age, and 29 to 60 days of age. The recommendations in this guideline do not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate.