Aseptic meningitis in adults and children: Diagnostic and management challenges

Methods for rapid diagnosis of meningitis etiology in adults

Infectious meningitis can be caused by viral, bacterial or fungal pathogens. Despite widely available treatments, many types of infectious meningitis are still associated with significant morbidity and mortality. Delay in diagnosis contributes to poor outcomes. Cerebrospinal fluid cultures have been used traditionally but are time intensive and sensitivity is decreased by empiric treatment prior to culture. More rapid techniques such as the cryptococcal lateral flow assay (IMMY), GeneXpert MTB/Rif Ultra (Cepheid) and FilmArray multiplex-PCR (Biofire) are three examples that have drastically changed meningitis diagnostics. This review will discuss a holistic approach to diagnosing bacterial, mycobacterial, viral and fungal meningitis.

A Case Report: Aseptic Meningitis

Meningitis is an inflammation of the leptomeninges which surround the brain and the spinal cord. Depending on the organism, it is categorized as aseptic or bacterial meningitis. Cerebro-spinal fluid analyse and its culture are used for this categorization. Although it is thought to occur more frequent in paediatric population, 7.6 out of 100000 adults are affected by the disease. Some people may have sequels such as cognitive impairment, focal neurologic deficits and hearing loss. The mortality of viral meningitis is 4.5%, while it is 14.8% with bacterial meningitis. Headache, nausea and vomiting are the most seen complaints in the early stages of the disease. Because of that it can primarily be misdiagnosed with upper respiratory tract infections but also with other diseases. Therefore, some people may have a late diagnose. That increases the morbidity and the mortality. This case report, describes a patient who was diagnosed with aseptic meningitis. The patient presented herself to our clinic with the complaints of headache, intermittent fever, stomach ache, and voiding difficulty. Keywords: aseptic meningitis, Family Practice, vaccination

Investigating the etiologic agents of aseptic meningitis outbreak in Iranian children

INTRODUCTION

This study aimed to determine the viral agent (s) and their genome burden associated with an aseptic meningitis outbreak that occurred in Yasuj, Iran.

MATERIALS AND METHODS

During April to August 2015, 104 CSF samples from 104 patients under 14 years old admitted to the hospital of Yasuj, Iran, with aseptic meningitis associated clinical signs were collected. 200 μl CSF specimens was prepared for DNA and RNA viral genome extraction each and then subjected to diagnostic Taq-man real time PCR assays for the present of Enteroviruses, HSV, VZV, mumps, measles and rubella in the samples.

RESULTS

The majority of them had experienced clinical meningitis sign. Primary laboratory differentiated tests were in favor of viral meningitis. Among a total of 104 patients diagnosed with clinically aseptic meningitis, enterovirus as the most significant viral agent was detected in 53 subjects. However, mumps, HSV and VZV, as the endemic causes of viral meningitis, were detected in 6, 6 and 2 of the affected patients. It was revealed that two HSV and one VZV affected patients were co-infected with enteroviruses. All affected children with relatively variable viral load recovered without any sequels.

CONCLUSION

The present study revealed enterovirus as the main predominant cause of pediatric aseptic meningitis that broke out in Yasuj-Iran. Also, the co-circulation of mumps, HSV and VZV, as the endemic cause during the same aseptic meningitis outbreak, was demonstrated in some cases.

Understanding and managing acute encephalitis

Encephalitis is an important cause of morbidity, mortality, and permanent neurologic sequelae  globally. Causes are diverse and include viral and non-viral infections of the brain as well as autoimmune processes. In the West, the autoimmune encephalitides are now more common than any single infectious cause, but, in Asia, infectious causes are still more common. In 2006, the World Health Organization coined the term "acute encephalitis syndrome", which simply means acute onset of fever with convulsions or altered consciousness or both. In 2013, the International Encephalitis Consortium set criteria for diagnosis of encephalitis on basis of clinical and laboratory features. The most important infectious cause in the West is herpes simplex virus, but globally Japanese encephalitis (JE) remains the single largest cause. Etiologic diagnosis is difficult because of the large number of agents that can cause encephalitis. Also, the responsible virus may be detectable only in the brain and is either absent or transiently found in blood or cerebrospinal fluid (CSF). Virological diagnosis is complex, expensive, and time-consuming. Different centres could make their own algorithms for investigation in accordance with the local etiologic scenarios. Magnetic resonance imaging (MRI) and electroencephalography are specific for few agents. Clinically, severity may vary widely. A severe case may manifest with fever, convulsions, coma, neurologic deficits, and death. Autoimmune encephalitis (AIE)  includes two major categories: (i) classic paraneoplastic limbic encephalitis (LE) with autoantibodies against intracellular neuronal antigens (Eg: Hu and Ma2) and (ii) new-type AIE with autoantibodies to neuronal surface or synaptic antigens (Eg: anti-N-methyl-D-aspartate receptor). AIE has prominent psychiatric manifestations: psychosis, aggression, mutism, memory loss, euphoria, or fear. Seizures, cognitive decline, coma, and abnormal movements are common. Symptoms may fluctuate rapidly. Treatment is largely supportive. Specific treatment is available for herpesvirus group and non-viral infections. Various forms of immunotherapy are used for AIE.

Meningitis gone viral: description of the echovirus wave 2013 in Germany

Background

Aseptic meningitis epidemics may pose various health care challenges.

Methods

We describe the German enterovirus meningitis epidemics in the university hospital centers of Düsseldorf, Cologne and Berlin between January 1st and December 31st, 2013 in order to scrutinize clinical differences from other aseptic meningitis cases.

Results

A total of 72 enterovirus (EV-positive) meningitis cases were detected in our multicenter cohort, corresponding to 5.8% of all EV-positive cases which were voluntarily reported within the National Enterovirus surveillance (EVSurv, based on investigation of patients with suspected aseptic meningitis/encephalitis and/or acute flaccid paralysis) by physicians within this period of time. Among these 72 patients, 38 (52.8%) were enterovirus positive and typed as echovirus (18 pediatric and 20 adult cases, median age 18.5 years; echovirus 18 (1), echovirus 2 (1), echovirus 30 (31), echovirus 33 (1), echovirus 9 (4)). At the same time, 45 aseptic meningitis cases in our cohort were excluded to be due to enteroviral infection (EV-negative). Three EV-negative patients were tested positive for varicella zoster virus (VZV) and 1 EV-negative patient for herpes simplex virus 2. Hospitalization was significantly longer in EV-negative cases. Cerebrospinal fluid analysis did not reveal significant differences between the two groups. After discharge, EV-meningitis resulted in significant burden of sick leave in our pediatric cohort as parents had to care for the children at home.

Conclusions

Voluntary syndromic surveillance, such as provided by the EVSurv in our study may be a valuable tool for epidemiological research. Our analyses suggest that EV-positive meningitis predominantly affects younger patients and may be associated with a rather benign clinical course, compared to EV-negative cases.

Encephalitis and aseptic meningitis: short-term and long-term outcome, quality of life and neuropsychological functioning

For those surviving encephalitis, the influence on daily life of patients and their relatives may be substantial. In contrast, the prognosis after aseptic meningitis (ASM) is considered good. In this prospective study in patients with encephalitis (n = 20) and ASM (n = 46), we show that both groups experienced reduced Health Related Quality of Life (HRQoL) at two months after discharge, and that workability was reduced in 37% of the patients with ASM. However, 12 months after discharge no neuropsychological deficits were detected in the ASM group, whereas patients with encephalitis had lower scores on tests of fine motor and psychomotor skills as well as on learning and memory. We also found that for patients with encephalitis, neopterin, as a marker of Th1 cell induced macrophage activation, and a putatively neurotoxic ratio of the kynurenine pathway (KP) measured during the acute phase was associated with lower HRQoL. Our data show that not only encephalitis, but also ASM has substantial short-term influence on HRQoL and workability. For patients with encephalitis we suggest a link between immune activation and activation of the KP during the acute phase with impaired HRQoL.

Development and verification of a discriminate algorithm for diagnosing post-neurosurgical bacterial meningitis-A multicenter observational study

Objective

To evaluate the diagnostic accuracy of cerebrospinal fluid (CSF)–based routine clinical examinations for post‐neurosurgical bacterial meningitis (PNBM) in multicenter post‐neurosurgical patients.

Methods

The diagnostic accuracies of routine examinations to distinguish between PNBM and post‐neurosurgical aseptic meningitis (PNAM) were evaluated by determining the values of the area under the curve (AUC) of the receiver operating characteristic curve in a retrospective analysis of post‐neurosurgical patients in four centers.

Results

An algorithm was constructed using the logistic analysis as a classical method to maximize the capacity for differentiating the two classes by integrating the measurements of five variables. The AUC value of this algorithm was 0.907, which was significantly higher than those of individual routine blood/CSF examinations. The predicted value from 70 PNBM patients was greater than the cutoff value, and the diagnostic accuracy rate was 75.3%. The results of 181 patients with PNAM showed that 172 patients could be correctly identified with specificity of 95.3%, while the overall correctness rate of the algorithm was 88.6%.

Conclusions

Routine biomarkers such as CSF/blood glucose ratio (C/B‐Glu), CSF lactate (C‐Lac), CSF glucose concentration (C‐Glu), CSF leukocyte count (C‐Leu), and blood glucose concentration (B‐Glu) can be used for auxiliary diagnosis of PNBM. The multicenter retrospective research revealed that the combination of the five abovementioned biomarkers can effectively improve the efficacy of the PNBM diagnosis.

Consistent, Excess Viral Meningitis Incidence Rates in Young Males: A Multi-country, Multi-year, Meta-analysis of National Data. The Importance of Sex as a Biological Variable

BACKGROUND

Sex can be an important biological variable in the immune response to infections and the response to vaccines. The magnitude and consistency in age-specific sex differences in the incidence of viral infections remain unclear.

METHODS

We obtained data from national official agencies on cases of viral meningitis by sex and age group over a period of 6-16 years from five countries: Canada, Czech Republic, Germany, Israel, and Poland. Male to female incidence rate ratios (RR) were computed for each year, by country, and age group. For each age group, we used meta-analysis methodology to combine the incidence RRs. Meta-regression was conducted to the estimate the effects of age, country, and time period on the RR.

FINDINGS

In the age groups < 1, 1-4, 5-9, 10-14, there were consistently higher incidence rates in males, over countries and time. The pooled incidence RRs (with 95% CI) were 1.38 (1.30-1.47), 1.94 (1.85-2.03), 1.98 (1.88-2.07), and 1.58 (1.47-1.71) respectively. In young and middle-age adults there were no differences with pooled incidence RRs of 1.00 (0.97-1.03), and 0.97 (0.94-1.00), respectively. Sensitivity analysis confirms that the results are stable and robust. Meta-regression showed that almost all the variations in the incidence RRs were contributed by age group.

INTERPRETATION

The higher incidence rates from viral meningitis in males under the age of 15 are remarkably consistent across countries and time-periods. These findings emphasize the importance of sex as a biological variable in infectious diseases. This could provide keys to the mechanisms of infection and lead to more personalized treatment and vaccine doses and schedules.

FUNDING

There was no funding source for this article.

Aseptic meningitis

Aseptic meningitis is defined as meningeal inflammation - i.e. cerebrospinal fluid (CSF) pleocytosis≥5 cells/mm³ - not related to an infectious process. Etiologies of aseptic meningitis can be classified in three main groups: (i) systemic diseases with meningeal involvement, which include sarcoidosis, Behçet's disease, Sjögren's syndrome, systemic lupus erythematosus and granulomatosis with polyangiitis; (ii) drug-induced aseptic meningitis, mostly reported with non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics (sulfamides, penicillins), intravenous immunoglobulin, and monoclonal antibodies; (iii) neoplastic meningitis, either related to solid cancer metastasis (breast cancer, lung cancer, melanoma) or malignant hemopathy (lymphoma, leukemia). Most series in the literature included groups of meningitis that are not stricto sensu aseptic, but should rather be included in the differential diagnosis: (i) infectious meningitis related to virus, parasites, fungi, or fastidious bacteria that require specific diagnostic investigations; (ii) bacterial meningitis with sterile CSF due to previous antibiotic administration, and (iii) parameningeal infections associated with meningeal reaction. Despite progress in microbiological diagnosis (including PCR, and next generation sequencing), and identification of a growing panel of autoimmune or paraneoplastic neurological syndromes, up to two thirds of aseptic meningitis cases are of unknown etiology, finally labeled as 'idiopathic'. Description of new entities, such as the syndrome of transient headache and neurologic deficits with cerebrospinal fluid lymphocytosis (HaNDL) may decrease the proportion of idiopathic aseptic meningitis. This state-of-the-art review summarizes the characteristics of main causes of aseptic meningitis.

Economic analysis of rapid multiplex polymerase chain reaction testing for meningitis/encephalitis in adult patients

PURPOSE

Many patients with suspected meningitis do not require hospitalization yet are admitted, often resulting in unnecessary care and additional cost. We assessed the possible economic impact of a rapid multiplex test for suspected adult community-acquired meningitis/encephalitis.

METHODS

A model simulated diagnosis, clinical decisions, resource use/costs of standard of care (SOC) and two cerebrospinal fluid (CSF) testing strategies using the FDA-cleared BioFire® FilmArray® System (FA) which provides results in approximately one hour.

RESULTS

Pathogens detected by FA caused approximately 74% of cases, 97% of which would be accurately diagnosed with FA. False positives and false negatives more often led to extended/unnecessary admission than inappropriate discharge/missed admission. Mean cost per case ranged from 16829 to 20791. A strategy of testing all suspected cases yielded greater savings (2213/case) than testing only those with abnormal CSF (812/case) and both were less expensive than SOC.

CONCLUSION

This economic analysis demonstrates that FA can inform more appropriate clinician decisions resulting in cost savings with greater economic benefits achievable with syndromic testing of all cases, rather than SOC or targeted syndromic testing.

Clinical Utilization of the FilmArray Meningitis/Encephalitis (ME) Multiplex Polymerase Chain Reaction (PCR) Assay

Objective: To assess the clinical utilization and performance of the FilmArray® Meningitis/Encephalitis (ME) multiplex polymerase chain reaction (PCR) panel in a hospital setting.

Background: Rapid diagnosis and treatment of central nervous system (CNS) infections are critical to reduce morbidity and mortality. The ME panel is a Food and Drug Administration (FDA) approved rapid multiplex PCR assay that targets 14 bacteria, viruses, and fungi. Previous studies show an overall agreement of 93–99% between the ME panel and conventional diagnostic testing. However, few studies have evaluated the clinical implementation of the ME assay, which is available for routine use at our institution.

Methods: We performed a single center retrospective chart review of inpatients who underwent ME panel testing from August 2016 to May 2017. Clinical, radiologic, and laboratory data were reviewed to determine the clinical significance of results. Indication for lumbar puncture (LP), time to results of the ME panel, and duration of antimicrobial therapy were evaluated.

Results: Seven hundred and five inpatients underwent ME testing, of whom 480 (68.1%) had clinical suspicion for CNS infection with 416 (59.0%) receiving empiric antimicrobial treatment for CNS infection. The median time-to-result of the ME panel was 1.5 h (IQR, 1.4–1.7). Overall agreement between the ME panel results and clinico-laboratory assessment was 98.2%. Forty-five patients tested positive by ME, of which 12 (26.6%) were determined likely to be clinically insignificant.

Conclusions: Routine availability of the ME panel led to overutilization of diagnostic test ordering, as demonstrated by the fact that over one-third of ME panel tests performed were ordered for patients with little or no suspicion for CNS infection. The median time from LP to ME panel result was 1.5 h (IQR, 1.4–1.7). The ME panel's rapid turn-around time contributed to the overuse of the test. Approximately one-quarter of positive ME results were deemed clinically insignificant, though the impact of these positive results requires additional evaluation. Twenty-four and forty-eight hours after the ME panel resulted, 68 and 25% of patients started on empiric therapy remained on antibiotics, respectively. The median time from diagnosis to discontinuation and/or narrowing of antibiotic coverage was 25.6 h (IQR, 3.6–42.5). Further consideration of the appropriate indications for use of the ME panel in clinical settings is required.

Impact of Enterovirus Molecular Assay Turnaround Time on Hospitalization Length During an Echovirus 30 Meningitis Outbreak, France, Fall 2014

Background:

The impact of Enterovirus Real Time-Polymerase Chain Reaction assay (EV RT-PCR) on hospitalization lengths of patients with aseptic meningitis has been investigated but the impact of early EV RT-PCR results released on time before patient discharge remains unclear during Echovirus meningitis outbreaks.

Objective:

To assess a potential correlation between EV RT-PCR turn-around time and hospitalization lengths during an Echovirus meningitis outbreak.

Method:

Eighteen patients demonstrating a positive EV RT-PCR assay performed on Cerebrospinal Fluid (CSF) samples collected between October 1st 2014 and December 31st 2014 were retrospectively included. Viral protein 1 (VP1) gene region was amplified and sequenced using a classical Sanger sequencing reaction. Clinical data were retrospectively collected from patient’s records. Quantitative variables expressed as median values and ranges were compared using Mann Whitney U test. Correlations were performed using simple regression analysis.

Results:

Phylogenetic VP1 sequence analyses identified that the outbreak was related to an Echovirus 30 strain in 7 out of the 10 cases with available sequencing data. The three remaining sequences analyses evidenced Echovirus 14, 9 and 7 strains. Hospitalization length was statistically shorter in children without comorbidity (n=5) than in adult patients (n=10) or neonates and children with comorbidity (n=3) (p=0.003 and 0.01 respectively), whereas EV RT-PCR turnaround time was not statistically different between these groups. Correlation between hospitalization length and EV RT-PCR turnaround time was poor (R2=0.06), especially in adults (R2=0.01)

Conclusion:

Our data indicated that EV RT-PCR turnaround time was not correlated to hospitalization length during a short Echovirus meningitis outbreak.

Epidemiology of Meningitis and Encephalitis in Infants and Children in the United States, 2011-2014

BACKGROUND

Large epidemiologic studies evaluating the etiologies, management decisions and outcomes of infants and children with meningitis and encephalitis in the United States are lacking.

METHODS

Children 0-17 years of age with meningitis or encephalitis as assessed by International Classification of Diseases, Ninth Revision, codes available in the Premier Healthcare Database during 2011-2014 were analyzed.

RESULTS

Six thousand six hundred sixty-five patients with meningitis or encephalitis were identified; 3030 (45.5%) were younger than 1 year of age, 295 (4.4%) were 1-2 years of age, 1460 (21.9%) were 3-9 years of age, and 1880 (28.2%) were 10-17 years of age. Etiologies included enterovirus (58.4%), unknown (23.7%), bacterial (13.0%), noninfectious (3.1%), herpes simplex virus (1.5%), other viruses (0.7%), arboviruses (0.5%) and fungal (0.04%). The majority of patients were male [3847 (57.7%)] and healthy [6094 (91.4%)] with no reported underlying conditions. Most underwent a lumbar puncture in the emergency department [5363 (80%)] and were admitted to the hospital [5363 (83.1%)]. Antibiotic therapy was frequent (92.2%) with children younger than 1 year of age with the highest rates (97.7%). Antiviral therapy was less common (31.1%). Only 539 (8.1%) of 6665 of patients received steroids. Early administration of adjunctive steroids was not associated with a reduction in mortality (P = 0.266). The overall median length of stay was 2 days. Overall mortality rate (0.5%) and readmission rates (<1%) was low for both groups.

CONCLUSION

Meningitis and encephalitis in infants and children in the United States are more commonly caused by viruses and are treated empirically with antibiotic therapy and antiviral therapy in a significant proportion of cases. Adjunctive steroids are used infrequently and are not associated with a benefit in mortality.

Cost of managing meningitis and encephalitis among infants and children in the United States

A retrospective cohort study design was used to assess the use and costs of diagnostic tests, medication, and total hospitalization costs for pediatric patients with suspected meningitis/encephalitis who received a lumbar puncture (LP) procedure. Related costs were calculated by timing of LP performed and infectious etiology for infants (<1 year) and children (1-17 years). A total of 3030 infants and 3635 children with suspected ME diagnosed between 2011 and 2014 were included in the study. The mean hospitalization cost for infants and children was $12,759 and $11,119, respectively, with medication and laboratory test costs of $834 and $1771 for infants and $825 and $855 for children, respectively. Total visit cost increased with delayed LP procedure, ICU stay, and if the etiology was viral (other than enterovirus or arbovirus) or bacterial. Higher diagnostic and treatment costs were associated with delayed LP procedure, etiologic agent, and ICU stay.

Development and Assessment of a Diagnostic DNA Oligonucleotide Microarray for Detection and Typing of Meningitis-Associated Bacterial Species

Meningitis is commonly caused by infection with a variety of bacterial or viral pathogens. Acute bacterial meningitis (ABM) can cause severe disease, which can progress rapidly to a critical life-threatening condition. Rapid diagnosis of ABM is critical, as this is most commonly associated with severe sequelae with associated high mortality and morbidity rates compared to viral meningitis, which is less severe and self-limiting. We have designed a microarray for detection and diagnosis of ABM. This has been validated using randomly amplified DNA targets (RADT), comparing buffers with or without formamide, in glass slide format or on the Alere ArrayTube^TM (Alere Technologies GmbH) microarray platform. Pathogen-specific signals were observed using purified bacterial nucleic acids and to a lesser extent using patient cerebral spinal fluid (CSF) samples, with some technical issues observed using RADT and glass slides. Repurposing the array onto the Alere ArrayTube^TM platform and using a targeted amplification system increased specific and reduced nonspecific hybridization signals using both pathogen nucleic and patient CSF DNA targets, better revealing pathogen-specific signals although sensitivity was still reduced in the latter. This diagnostic microarray is useful as a laboratory diagnostic tool for species and strain designation for ABM, rather than for primary diagnosis.