Viral meningitis: current issues in diagnosis and treatment

Neurologic Emergencies in Pregnancy

Neurologic emergencies in pregnancy require prompt evaluation and early, focused intervention to improve neurologic outcomes for the affected person and to avoid further injury. Neurologic events in pregnancy, although rare, present a time of extreme risk of permanent injury for the person who is pregnant. Therefore, obstetric clinicians should be well versed in the risk factors for potential neurologic events and understand the symptoms and events that should prompt evaluation for a neurologic event. In addition, they should support other specialties in aggressive and early neurologic care for the patient to improve outcomes while assessing fetal well-being and care optimization for the dyad. Obstetric clinicians can uniquely provide knowledge of changes in pregnancy physiology that can increase the risk of neurologic events, as well as change the treatment of these events. For all patients with neurologic events, "time is brain." Therefore, it is important to be aware of changes in common presenting pregnancy concerns that should prompt evaluation for other pathogeneses. Finally, pregnancy care teams should be prepared to begin the initial stabilization and management of acute neurologic emergencies, including seizure, stroke, and meningitis, while seeking aid from other medical and neurologic specialists who can support their care and interventions. Early and aggressive interventions for individuals with neurologic events during pregnancy and postpartum are critical to the overall well-being of the dyad.

Detection of intrathecal IgG antibody for varicella and measles diagnosis by evaluation and comparison of a commercial IgG chemiluminescent immunoassay with two ELISAs

OBJECTIVES

Analyse alternative methods of intrathecal antibody detection by comparing chemiluminescent immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) techniques to determine if CLIA can replace ELISA in the diagnosis of CNS infections.

METHODS

A panel of 280 paired samples-cerebrospinal fluid (CSF) and serum-with known antibody reactivities (Varicella, n = 60; Measles, n = 120) and negative samples (n = 100) were used to evaluate the performance of six serological test kits (Enzygnost, VirClia®, and Serion ELISA (Measles and Variella).

RESULTS

For Measles virus IgG, the VirClia® IgG monotest revealed 97% and 94% positive and negative agreement to the Enzygnost as reference test, respectively. In contrast, Serion ELISA kits yielded values of 18% and 90%. For the Varicella Zoster virus (VZV) IgG, the VirClia® IgG monotest showed 97% and 90% positive and negative agreement compared to Enzygnost. The Serion ELISA kits showed values of 55% and 86%, respectively. ROC analysis revealed that the areas under the curve for Measles and VZV IgGs were 0.7 and 0.852, respectively, using the Serion kit, and 0.963 and 0.955, for Vircell S.L CLIA technique. VirClia® monotest values were calculated using an antibody index cut-off of 1.3.

CONCLUSION

The findings indicate that CLIA testing can improve antibody detection in CSF samples, aiding the diagnosis of infectious neurological impairments.

Square the Circle: Diversity of Viral Pathogens Causing Neuro-Infectious Diseases

Neuroinfections rank among the top ten leading causes of child mortality globally, even in high-income countries. The crucial determinants for successful treatment lie in the timing and swiftness of diagnosis. Although viruses constitute the majority of infectious neuropathologies, diagnosing and treating viral neuroinfections remains challenging. Despite technological advancements, the etiology of the disease remains undetermined in over half of cases. The identification of the pathogen becomes more difficult when the infection is caused by atypical pathogens or multiple pathogens simultaneously. Furthermore, the modern surge in global passenger traffic has led to an increase in cases of infections caused by pathogens not endemic to local areas. This review aims to systematize and summarize information on neuroinvasive viral pathogens, encompassing their geographic distribution and transmission routes. Emphasis is placed on rare pathogens and cases involving atypical pathogens, aiming to offer a comprehensive and structured catalog of viral agents with neurovirulence potential.

Diagnostic accuracy of inflammatory markers in adults with suspected central nervous system infections

OBJECTIVES

We aimed to determine diagnostic accuracy of inflammatory markers in plasma and cerebrospinal fluid (CSF) for the diagnosis of central nervous system (CNS) infections and specifically bacterial meningitis.

METHODS

We analyzed 12 cytokines, chemokines, and acute phase reactants in CSF and plasma of 738 patients with suspected neurological infection included in a multicenter prospective cohort. We determined diagnostic accuracy for predicting any CNS infection and bacterial meningitis.

RESULTS

We included 738 episodes between 2017 and 2022, split into a derivation (n = 450) and validation cohort (n = 288). Of these patients, 224 (30%) were diagnosed with CNS infection, of which 81 (11%) with bacterial meningitis, 107 (14%) with viral meningitis or encephalitis, and 35 patients (5%) with another CNS infection. Diagnostic accuracy of CRP, IL-6, and Il-1β in CSF was high, especially for diagnosing bacterial meningitis. Combining these biomarkers in a multivariable model increased accuracy and provided excellent discrimination between bacterial meningitis and all other disorders (AUC = 0.99), outperforming all individual biomarkers as well as CSF leukocytes (AUC = 0.97). When applied to the population of patients with a CSF leukocyte count of 5-1000 cells/mm3, accuracy of the model also provided a high diagnostic accuracy (AUC model = 0.97 vs. AUC CSF leukocytes = 0.80) with 100% sensitivity and 92% specificity. These results remained robust in a temporal validation cohort.

CONCLUSIONS

Inflammatory biomarkers in CSF are able to differentiate CNS infections and especially bacterial meningitis from other disorders. When these biomarkers are combined, their diagnostic accuracy exceeds that of CSF leukocytes alone and as such these markers have added value to current clinical practice.

Pro-inflammatory cerebrospinal fluid profile of neonates with intraventricular hemorrhage: clinical relevance and contrast with CNS infection

BACKGROUND

Interpretation of cerebrospinal fluid (CSF) studies can be challenging in preterm infants. We hypothesized that intraventricular hemorrhage (IVH), post-hemorrhagic hydrocephalus (PHH), and infection (meningitis) promote pro-inflammatory CSF conditions reflected in CSF parameters.

METHODS

Biochemical and cytological profiles of lumbar CSF and peripheral blood samples were analyzed for 81 control, 29 IVH grade 1/2 (IVH1/2), 13 IVH grade 3/4 (IVH3/4), 15 PHH, 20 culture-confirmed bacterial meningitis (BM), and 27 viral meningitis (VM) infants at 36.5 ± 4 weeks estimated gestational age.

RESULTS

PHH infants had higher (p < 0.02) CSF total cell and red blood cell (RBC) counts compared to control, IVH1/2, BM, and VM infants. No differences in white blood cell (WBC) count were found between IVH3/4, PHH, BM, and VM infants. CSF neutrophil counts increased (p ≤ 0.03) for all groups compared to controls except IVH1/2. CSF protein levels were higher (p ≤ 0.02) and CSF glucose levels were lower (p ≤ 0.003) for PHH infants compared to all other groups. In peripheral blood, PHH infants had higher (p ≤ 0.001) WBC counts and lower (p ≤ 0.03) hemoglobin and hematocrit than all groups except for IVH3/4.

CONCLUSIONS

Similarities in CSF parameters may reflect common pathological processes in the inflammatory response and show the complexity associated with interpreting CSF profiles, especially in PHH and meningitis/ventriculitis.

Characteristics and long-term prognosis of Danish residents with a positive intrathecal antibody index test for herpes simplex virus or varicella-zoster virus compared with individuals with a positive cerebrospinal fluid PCR: a nationwide cohort study

OBJECTIVES

We compared characteristics and outcomes of individuals who in the cerebrospinal fluid (CSF) were positive for herpes simplex virus (HSV) or varicella-zoster virus (VZV)-intrathecal antibody index test ([AI]-positive) vs. individuals who were PCR-positive for HSV type 1 (HSV1), type 2 (HSV2), and for VZV.

METHODS

Nationwide cohort study of all Danish residents with positive CSF-AI or -PCR for HSV or VZV (1995-2021). We calculated short- and long-term risks as age-, sex-, and comorbidity-adjusted odds ratios (aOR), adjusted hazard ratios (aHR), and absolute risk differences with 95% CIs.

RESULTS

Compared with individuals with positive PCR for HSV1 (n = 321), HSV2 (n = 497), and VZV (n = 1054), individuals with a positive AI for HSV (n = 177) and VZV (n = 219) had CSF pleocytosis less frequently (leucocyte count >10/μL: HSV-AI: 39%, VZV-AI: 52%, HSV1-PCR: 81%, HSV2-PCR: 92%, VZV-PCR: 83%), and were less frequently diagnosed with central nervous system infection ([aOR {95%CI}]: HSV-AI vs. HSV1-PCR: [0.1 {0.1, 0.2}], HSV-AI vs. HSV2-PCR: [0.1 {0.0, 0.1}], VZV-AI vs. VZV-PCR: [0.2 {0.2, 0.3}]). Individuals with a positive HSV-AI or VZV-AI had increased risk of demyelinating disease ([aOR {95%CI}; aHR {95%CI}]: HSV-AI vs. HSV1-PCR: [4.6 {0.9, 24.5}; aHR not applicable], HSV-AI vs. HSV2-PCR: [10.4 {2.3, 45.9}; 12.4 {2.3, 66.0}], VZV-AI vs. VZV-PCR: [aOR not applicable; 10.3 {1.8, 58.8}]). Disability pension was less frequent among HSV-AI than HSV1-PCR cohort members (5-year risk difference: -23.6%, 95%CI: -35.2, -11.8), and more frequent among VZV-AI than VZV-PCR cohort members (5-year risk difference: 16.8%, 95%CI: 5.0, 28.7).

DISCUSSION

AI-positive individuals differ from PCR-positive individuals in several aspects. AI appears unspecific for current central nervous system infections.

Pediatric central nervous system infections in the Amazon: clinical and laboratory profiles

Background

Central nervous system (CNS) infections are important causes of mortality and morbidity in children, and they are related to severe problems such as hearing loss, neurological sequelae, and death. The objective was to describe clinical and laboratory exam profiles of children who were diagnosed with CNS infections.

Methods

We conducted a cross-sectional study based on medical records, which included pediatric patients aged from 3 months to 15 years, with a clinical suspicion of CNS infection between January 2014 to December 2019. The pathogens were confirmed in cerebrospinal fluid (CSF) samples using Gram staining, cell culture, molecular diagnostics (PCR and qPCR), and serology.

Results

Out of the 689 enrolled patients, 108 (15.6%) had laboratory-confirmed infections in CSF. The most common bacterial pathogens isolated from the culture were Neisseria meningitidis serogroup C in 19, Streptococcus pneumoniae in 11, and Haemophilus influenzae in seven samples. The viruses identified were Enterovirus, Cytomegalovirus, Varicella-zoster virus, Epstein-Barr virus, and arbovirus. No patient was found to be positive for Herpes simplex virus 1 and 2. Patients with viral infections showed altered levels of consciousness (p = 0.001) when compared to bacterial infections.

Conclusion

This study shows the presence of important vaccine-preventable pathogens, and different families of viruses causing CNS infections in the pediatric patients of Manaus.

Progress in etiological diagnosis of viral meningitis

In recent years, with the rapid development of molecular biology techniques such as polymerase chain reaction and molecular biochip, the etiological diagnosis of viral encephalitis has a very big step forward. At present, the etiological examination of viral meningitis mainly includes virus isolation, serological detection and molecular biological nucleic acid detection. This article reviews the progress in etiological diagnosis of viral meningitis.

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.

Disruption of seasonal enterovirus and parechovirus detections in the CSF and plasma of children during the COVID-19 pandemic

BACKGROUND

Enteroviruses (EV) and parechovirus (PeV) are a common cause of CNS infection in children. Both viruses demonstrate consistent seasonal patterns, with detections mainly in the summer-fall months. While research has shown COVID-19 pandemic-related disruption of traditional seasonality of respiratory pathogens, the pandemic's impact on non-respiratory pathogens is less understood. The aim of this study was to quantify the EV/PeV seasonal variations during pre-COVID years compared to variations observed during the COVID pandemic.

METHODS

Patients with EV/PeV testing of CSF/plasma between January 2012 through September 2022 were identified. Restricted cubic spline methods were used to model the detections. Poisson models were utilized to model pre-COVID (2012-2019) EV/PeV detections. The expected seasonal trends from these models were then compared to the observed EV/PeV detections during the COVID pandemic (2020-2022).

RESULTS

A total of 5199 patients were included. The annual pre-pandemic proportion of EV detections ranged between 7.5%-20.3%. PeV exhibited a biennial pattern with peak proportions between 8.0%-16.3%. EV/PeV detections during the COVID pandemic period, especially during 2020 and 2021, were considerably lower than would have been expected based on pre-pandemic modeling. However, PeV detections from January through September 2022 nearly reached the pre-pandemic modeled expectation, including instances of exceeded expectations.

CONCLUSIONS

A significant disruption in expected seasonal EV/PeV detections was observed during the early phases of the COVID-19 pandemic. However, testing that occurred during summer-fall of 2022, when social mitigation initiatives were relaxed, showed a rapid increase in detections. Additional data are needed to further understand which public health initiatives are effective at decreasing EV/PeV transmission.

An Atypical Case of Enterovirus Meningitis Presenting with Unilateral Optic Disc Swelling and Minimal Optical Symptoms

PURPOSE

To report a case of unilateral disc swelling as the only presentation of enterovirus meningitis in a 43-year-old male who presented with reduction in visual quality.

METHODS

Vision was 20/20 unaided in both eyes and the only ocular finding was left optic disc edema accompanied by left relative afferent pupillary defect. Visual field examination revealed a generalized reduction in sensitivity, a paracentral scotoma and a superior and inferior arcuate defect. Apart from a marginally elevated white blood cell count, the evaluation for common diseases associated with unilateral disc swelling was negative. A comprehensive neurology and rheumatology assessment,the orbital, brain and cervical spine Magnetic Resonance Imaging (MRI), the chest and abdomen Computed Tomography (CT) and chest radiograph had no findings. However, the cerebrosipinal fluid (CSF) examination indicated the presence of enterovirus RNA.

RESULTS

A diagnosis of enterovirus meningitis was established.Patient's general health was not affected and symptoms gradually settled, with no specific anti-enteroviral treatment.

CONCLUSION

Only the CSF analysis provided interesting evidence of the site of the visual dysfunction.

Clinical application value of metagenomic next-generation sequencing in the diagnosis of central nervous system infections

Objectives: The purpose of this study is to evaluate the clinical application value of metagenomic next-generation sequencing (mNGS) in central nervous system (CNS) infections. Methods: Both mNGS and routine examination of cerebrospinal fluid (CSF) samples from patients with CNS infections retrospectively analyzed the efficacy of mNGS in this cohort and were ultimately compared with a clinical diagnosis. Results: A total of 94 cases consistent with CNS infections were included in the analysis. The positive rate for mNGS is 60.6% (57/94), which is significantly higher than 20.2% (19/94; p < 0.01) detected using conventional methods. mNGS detected 21 pathogenic strains that could not be detected by routine testing. Routine tests were positive for two pathogens but negative for mNGS. The sensitivity and specificity of mNGS in the diagnosis of central nervous system infections were 89.5% and 44%, respectively, when compared with traditional tests. At discharge, 20 (21.3%) patients were cured, 55 (58.5%) patients showed improvements, five (5.3%) patients did not recover, and two (2.1%) patients died. Conclusion: mNGS has unique advantages in the diagnosis of central nervous system infections. mNGS tests can be performed when patients are clinically suspected of having a central nervous system infection but no pathogenic evidence.

Epidemiology and Disease Burden of Hospitalized Children With Viral Central Nervous System Infections in China, 2016 to 2020

BACKGROUND

Viral central nervous system (CNS) infections seriously threaten the life and health of children, with a high mortality and severe sequelae in China and globally. Surveillance of viral CNS infections in children is important, especially in hospitalized children, to facilitate disease evaluation.

METHODS

In this study, we collected the data on the discharged Face Sheet of Medical Records from database from 2016 to 2020 and analyzed the epidemiologic characteristics and disease burden of hospitalized children (≤18 years old) with viral CNS infections in China. We classified the discharge diagnosis of viral CNS infection as viral encephalitis (VE), viral meningitis (VM), viral meningoencephalitis (VME), viral encephalomyelitis (VEM), and viral meningomyelitis (VMM).

RESULTS

A total of 42,641 cases of viral CNS infections were included in the database, consisting of 39,279 cases with VE (92.47%), 2011 cases with VM (4.73%), 1189 cases with VME (2.80%), 118 cases with VEM (0.28%), and 44 cases with VMM (0.10%). The number of hospitalized patients with viral CNS infections accounted for 0.74% (42,641 of 5,790,910) of all hospitalized cases. The onset of viral CNS infections presented seasonal characteristic, with peaks in June to July and December to January. Seizures are the most frequent complication of this disorder. Median length of stay and inpatient expenditures for patients with viral CNS infections were 9 days and 1144.36 USD. Causative viruses were identified in 4.33% (1848 of 42,641) of patients.

CONCLUSIONS

This study will help understand the clinical epidemiology and disease burden of hospitalized children with viral CNS infections in China.

The cerebrospinal fluid neutrophil to lymphocyte ratio is a sensitive biomarker for bacterial meningitis in children

BACKGROUND

The cerebrospinal fluid neutrophil-to-lymphocyte ratio (CSF NLR) as a diagnostic biomarker of bacterial meningitis has been reported in adult trials. The aim of this study was to evaluate the CSF NLR as a diagnostic biomarker of bacterial meningitis in children and to define an optimal CSF NLR concentration.

METHODS

We performed a retrospective cohort study of children with clinical findings compatible with meningitis. CSF NLR was calculated as the ratio of neutrophil count to lymphocyte count in cerebrospinal fluid (CSF). Initial data included clinical, radiological, and laboratory diagnostics.

RESULTS

We determined CSF parameters from children with infectious meningitis (n = 348) and subdivided them into bacterial meningitis (n = 112) and viral meningitis (n = 236). CSF NLR was significantly higher in bacterial meningitis than in viral meningitis (P < 0.001), and its level was higher in Gram-negative bacterial infections than in Gram-positive bacterial infections (P = 0.01). In the receiver operating characteristic curve analysis, CSF NLR was better than CSF protein/sugar/WBC in the ability to distinguish bacterial meningitis from viral meningitis (AUC 0.91 ± 0.02 versus 0.88 ± 0.03/0.87 ± 0.03/0.86 ± 0.03), and using a cutoff point of 0.68, the sensitivity was 0.90, and the specificity was 0.75. Compared with Gram-positive infection, CSF NLR with Gram-negative infection was higher (media, IQR (1.18 (0.19-2.33) versus 3.90 (1.50-8.91), P = 0.01).

CONCLUSION

CSF NLR is a more useful diagnostic tool to distinguish between bacterial meningitis and viral meningitis in children. While at a cutoff value of 0.68, CSF NLR has better sensitivity and specificity for bacterial meningitis, and the higher level of CSF NLR could be related to Gram-negative bacterial infection.

Assessment of a multiplex RT-PCR for Simultaneous, Rapid Screening of Common Viral Infections of Central Nervous System: A Prospective Study for Enteroviruses and Herpesviruses

Introduction

Acute meningitis is a common neurological disorder that affects both children and adults and has a high mortality rate. This study aimed to create a multiplex reverse transcriptase PCR system for screening clinical samples for the presence of the two viruses currently considered to be the most common causes of acute meningitis in Asia.

Materials and Methods

A single-tube RT multiplex PCR assay was developed and tested for sensitivity and specificity using primers that have been commonly used to screen for herpes simplex viruses 1 and 2 (HSV-1/2) and enterovirus (EV) in clinical samples. The procedure was then used to screen 303 clinical samples for the target viruses, which included 101 feces samples, 101 throat swabs, and 101 cerebrospinal fluid (CSF) samples obtained from 101 hospitalized Iranian children with suspected viral meningitis/meningoencephalitis, and the findings were compared to those of an RT monoplex PCR method.

Results

The RT-PCR approach demonstrated high precision, with no non-target virus amplification. The results of using this assay to screen clinical samples revealed that RT monoplex PCR had the same sensitivity as RT multiplex PCR for the three different types of specimens.

Conclusions

This newly developed multiplex RT-PCR method is a simple, fast diagnostic tool that can be used to screen clinical samples for viruses that cause acute meningitis/meningoencephalitis in children.

[Viral meningitis: a rare cause of hyperventilation]

The etiology of hyperventilation is multifactorial. When excluding somatic causes, neurogenic hyperventilation must always be considered. Since hyperventilation itself causes neuromuscular symptoms such as paresthesia, vertigo, cephalgia, and nausea, the differential diagnosis of viral meningitis in the presence of hyperventilation is not always obvious and can easily be overlooked. Our case report shows that somatogenic causes of hyperventilation should be carefully excluded.

Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study

BACKGROUND

Acute meningitis or encephalitis (AME) results from a neurological infection causing high case fatality and severe sequelae. AME lacked comprehensive surveillance in China.

METHODS

Nation-wide surveillance of all-age patients with AME syndromes was conducted in 144 sentinel hospitals of 29 provinces in China. Eleven AME-causative viral and bacterial pathogens were tested with multiple diagnostic methods.

FINDINGS

Between 2009 and 2018, 20,454 AME patients were recruited for tests. Based on 9,079 patients with all-four-virus tested, 28.43% (95% CI: 27.50%‒29.36%) of them had at least one virus-positive detection. Enterovirus was the most frequently determined virus in children <18 years, herpes simplex virus and Japanese encephalitis virus were the most frequently determined in 18-59 and ≥60 years age groups, respectively. Based on 6,802 patients with all-seven-bacteria tested, 4.43% (95% CI: 3.94%‒4.91%) had at least one bacteria-positive detection, Streptococcus pneumoniae and Neisseria meningitidis were the leading bacterium in children aged <5 years and 5-17 years, respectively. Staphylococcus aureus was the most frequently detected in adults aged 18-59 and ≥60 years. The pathogen spectrum also differed statistically significantly between northern and southern China. Joinpoint analysis revealed age-specific positive rates, with enterovirus, herpes simplex virus and mumps virus peaking at 3-6 years old, while Japanese encephalitis virus peaked in the ≥60 years old. As age increased, the positive rate for Streptococcus pneumoniae and Escherichia coli statistically significantly decreased, while for Staphylococcus aureus and Streptococcus suis it increased.

INTERPRETATION

The current findings allow enhanced identification of the predominant AME-related pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures in China, and a possible reassessment of vaccination strategy.

FUNDING

China Mega-Project on Infectious Disease Prevention and the National Natural Science Funds.

Review on inactivation of airborne viruses using non-thermal plasma technologies: from MS2 to coronavirus

Although several non-thermal plasmas (NTPs) technologies have been widely investigated in air treatment, very few studies have focused on the inactivation mechanism of viruses by NTPs. Due to its efficiency and environmental compatibility, non-thermal plasma could be considered a promising virus-inactivation technology. Plasma is a partly or fully ionized gas including some species (i.e., electrons, free radicals, ions, and neutral molecules) to oxidize pollutants or inactivate harmful organisms. Non-thermal plasmas are made using less energy and have an active electron at a much higher temperature than bulk gas molecules. This review describes NTPs for virus inactivation in indoor air. The different application processes of plasma for microorganism inactivation at both laboratory and pilot-scale was also reviewed This paper reports on recent advances in this exciting area of viral inactivation identifying applications and mechanisms of inactivation, and summarizing the results of the latest experiments in the literature. Moreover, special attention was paid to the mechanism of virus inactivation. Finally, the paper suggests research directions in the field of airborne virus inactivation using non-thermal plasma.

A Case Series on Enteroviral Meningitis in Pakistan

Enteroviruses (EVs) are the most common cause of viral meningitis with a peak incidence between late summer and fall. The onset of symptoms is characteristically abrupt and typically includes headache, fever, nausea or vomiting, malaise, photophobia, and meningismus. In addition, diarrhea, upper respiratory symptoms, and a rash may also be present. The clinical presentation and epidemiologic features help in the diagnosis and it is confirmed by the detection of RNA in the cerebrospinal fluid (CSF) by polymerase chain reaction (PCR). We present the clinical description, diagnosis, and management of five consecutive cases of viral meningitis secondary to enterovirus that presented to the emergency department at a tertiary care center in Karachi, Pakistan, over a span of five weeks during the monsoon season. These cases or outbreaks have not been reported previously in Pakistan and, hence, this case series is the first of its kind.

All of our patients were young males, with ages between 18-35 years, did not have any prior co-morbidities, and resided in different localities of Karachi, Pakistan. The presenting complaints were severe headache in all five patients (100%), fever in all five patients (100%), and diarrhea in two out of five patients (40%). On examination, neck stiffness was present in all patients (100%). After the required workup and detection of RNA in the CSF by PCR, diagnosis of enteroviral meningitis was confirmed. The patients were given symptomatic treatment and discharged home with no neurologic complications. Aseptic meningitis occurring during the summer or fall is most likely to be caused by non-polio EVs (eg. coxsackievirus, echovirus, etc.). It is self-limiting and only requires supportive treatment. However, clinically it cannot be differentiated from other central nervous system infections and significant morbidity has been reported, including hospitalization and impairment of routine activities.

High rate of human enteroviruses among clinically suspected meningitis cases at selected Hospitals in Addis Ababa, Ethiopia

BACKGROUND

Because of limited infrastructure and skilled human capital, the etiology of meningitis is rarely identified in developing countries like Ethiopia. This results in unnecessary antibiotics use, economic crisis, hospitalization, and related nosocomial infections. Thus, we aimed to assess the epidemiology of human enteroviruses (HEVs) among clinically suspected meningitis cases in Addis Ababa, Ethiopia.

METHOD

A cross-sectional study was conducted from January to August 2020 at selected Hospitals in Addis Ababa, Ethiopia. Reverse transcriptase-polymerase chain reaction (RT-PCR) was conducted on cerebrospinal fluid (CSF) collected from 146 clinically suspected meningitis and bacterial culture-negative patients. SPSS v 21.0 was used for data analysis and bivariate correlation was done for the association between variables of interest.

RESULTS

HEVs were detected in 39 (26.7%) of the 146 clinically suspected meningitis cases. Most of the HEVs cases 28 (71.9%) were detected in younger-aged infants less than 1 year. The most commonly observed clinical manifestations were vomiting (75.5%) followed by fever (56.8%) and impaired consciousness or irritability (50.7%). The mean length of hospital stay for patients with enteroviral meningitis was 9 days. Many patients with HEVs were recovered with sequelae (46.2%), and HEVs has contributed for one out of the nine meningeal deaths (11.1%).

CONCLUSIONS

HEVs were found to be the commonest cause of morbidity and mortality in all age groups. Many of the patients were mistreated with antibiotics and hospitalized. The detection of HEVs in 26.7% of clinically suspected meningitis cases indicated the need for molecular tests in investigating the etiology of meningitis. Therefore, we suggest the introduction of molecular tests as a routine practice in referral hospitals and the need to further characterize circulating HEVs strains.

Update on Viral Infections Involving the Central Nervous System in Pediatric Patients

Infections of the central nervous system (CNS) are mainly caused by viruses, and these infections can be life-threatening in pediatric patients. Although the prognosis of CNS infections is often favorable, mortality and long-term sequelae can occur. The aims of this narrative review were to describe the specific microbiological and clinical features of the most frequent pathogens and to provide an update on the diagnostic approaches and treatment strategies for viral CNS infections in children. A literature analysis showed that the most common pathogens worldwide are enteroviruses, arboviruses, parechoviruses, and herpesviruses, with variable prevalence rates in different countries. Lumbar puncture (LP) should be performed as soon as possible when CNS infection is suspected, and cerebrospinal fluid (CSF) samples should always be sent for polymerase chain reaction (PCR) analysis. Due to the lack of specific therapies, the management of viral CNS infections is mainly based on supportive care, and empiric treatment against herpes simplex virus (HSV) infection should be started as soon as possible. Some researchers have questioned the role of acyclovir as an empiric antiviral in older children due to the low incidence of HSV infection in this population and observed that HSV encephalitis may be clinically recognizable beyond neonatal age. However, the real benefit-risk ratio of selective approaches is unclear, and further studies are needed to define appropriate indications for empiric acyclovir. Research is needed to find specific therapies for emerging pathogens. Moreover, the appropriate timing of monitoring neurological development, performing neuroimaging evaluations and investigating the effectiveness of rehabilitation during follow-up should be evaluated with long-term studies.

Living on the Edge of the CNS: Meninges Cell Diversity in Health and Disease

The meninges are the fibrous covering of the central nervous system (CNS) which contain vastly heterogeneous cell types within its three layers (dura, arachnoid, and pia). The dural compartment of the meninges, closest to the skull, is predominantly composed of fibroblasts, but also includes fenestrated blood vasculature, an elaborate lymphatic system, as well as immune cells which are distinct from the CNS. Segregating the outer and inner meningeal compartments is the epithelial-like arachnoid barrier cells, connected by tight and adherens junctions, which regulate the movement of pathogens, molecules, and cells into and out of the cerebral spinal fluid (CSF) and brain parenchyma. Most proximate to the brain is the collagen and basement membrane-rich pia matter that abuts the glial limitans and has recently be shown to have regional heterogeneity within the developing mouse brain. While the meninges were historically seen as a purely structural support for the CNS and protection from trauma, the emerging view of the meninges is as an essential interface between the CNS and the periphery, critical to brain development, required for brain homeostasis, and involved in a variety of diseases. In this review, we will summarize what is known regarding the development, specification, and maturation of the meninges during homeostatic conditions and discuss the rapidly emerging evidence that specific meningeal cell compartments play differential and important roles in the pathophysiology of a myriad of diseases including: multiple sclerosis, dementia, stroke, viral/bacterial meningitis, traumatic brain injury, and cancer. We will conclude with a list of major questions and mechanisms that remain unknown, the study of which represent new, future directions for the field of meninges biology.

Volatile Organic Compounds to Identify Infectious (Bacteria/Viruses) Diseases of the Central Nervous System: A Pilot Study

BACKGROUND

Central nervous system (CNS) infectious diseases are common diseases in emergency rooms and neurology departments. CNS pathogen identification methods are time consuming and expensive and have low sensitivity and poor specificity. Some studies have shown that bacteria and viruses can produce specific volatile organic compounds (VOCs). The aim of this study is to find potential biomarkers by VOC analysis of cerebrospinal fluid (CSF) in patients with bacterial and viral meningitis/encephalitis (ME).

METHODS

CSF samples from 16 patients with bacterial ME and 42 patients with viral ME were collected, and solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze the metabolites in the CSF.

RESULTS

There are 2 substances (ethylene oxide and phenol) that were found to be different between the 2 groups. Ethylene oxide was significantly greater in the group of bacterial ME patients than in the viral ME group of patients (p < 0.05). In addition, phenol was remarkably increased in the group of ME patients compared with the bacterial ME patients (p < 0.05).

CONCLUSIONS

Ethylene oxide and phenol may be potential biomarkers to distinguish bacterial ME and viral ME. VOC analysis of CSF may be used as a supporting tool for clinical diagnosis.

Clinical and laboratory detection of nonpolio enteroviruses among different age groups of aseptic meningitis patients in Alexandria, Egypt

BACKGROUND

Viral meningitis is the most common type of meningitis. Worldwide, nonpolio enteroviruses (NPEVs) account for 23%-60% of all cases of viral meningitis. We aimed to detect NPEV among aseptic meningitis cases using reverse transcription-polymerase chain reaction (RT-PCR) and evaluate molecular testing versus clinical and laboratory parameters.

PATIENTS AND METHODS

A 2-year prospective study was conducted for all clinically suspected meningitis patients, who underwent lumbar puncture in Alshatby University and Alexandria Fever Hospitals. Clinical manifestations were reviewed; cytological, microbiological, and biochemical examinations were done. One-step RT-PCR for NPEV was introduced to a routine workflow using Pan-Enterovirus primers.

RESULTS

Out of 2519 patients, 994 (40%) patients were found to have positive cerebrospinal fluid findings, out of which 716 (72%) patients had positive findings of aseptic meningitis. Ninety-four samples were randomly selected and divided across four age groups: neonates, infants, children, and adults. The significant difference was found among adult patients regarding fever, vomiting, headache, signs of meningeal irritation, cranial nerve affection, and focal neurological deficits (p ≤ .05). Seven cases (7.4%) were found to be NPEV positive by RT-PCR. Positive NPEV PCR samples were shown to be statistically significant among neonates (p ≤ .05). The statistical significance was found among the NPEV group regarding the length of hospital stay and duration of IV antibiotic intake while no statistical significance was found with any clinical or laboratory findings.

CONCLUSION

RT-PCR was reliable to identify NPEV while clinical and laboratory findings were inconclusive. NPEV showed low incidence and slight seasonal variation which rings the bell to investigate other causes of viral meningitis throughout the year.

Adenovirus Infection-associated Central Nervous System Disease in Children

BACKGROUND

Adenovirus (Adv) is a frequent etiology of acute respiratory tract infections. Although rare, neurologic manifestations are known to occur during Adv infection.

METHODS

We retrospectively analyzed clinical, laboratory, outcome and the relationship between clinical characteristics and viral detection results in the cerebrospinal fluid (CSF) in children with Adv-associated central nervous system (CNS) dysfunction.

RESULTS TWENTYONE

(1.5%) cases had Adv-associated CNS manifestations. The median age was 1.4 years and 20 (95%) were less than 5 years of age. Six (28%) were male. The most frequently cited CNS symptoms were altered consciousness (100%) and seizure (14.3%). Fourteen cases (73.7%) had abnormal electroencephalogram examination and 6 cases (37.5%) had abnormal imaging. None of the patients had received cidofovir administration. Twenty children recovered without sequelae and 1 patient died of respiratory failure. Patients with positive Adv polymerase chain reaction (n = 11) presented lower onset age compared with that of patients with negative Adv polymerase chain reaction (n = 10) in the CSF. Clinical manifestation, laboratory findings, imaging studies and electroencephalogram showed no significant difference between the 2 groups.

CONCLUSION

Adv is a rare cause of CNS disease in children, mainly causing altered consciousness. Adv was detected in more cases in the respiratory tract than the CSF, but the majority of patients had the virus detected in both. The lack of Adv in the CSF does not exclude CNS involvement. Furthermore, the viral detection results in the CSF do not seem useful as an indicator of the severity of CNS disease.

Positive Impact of Routine Testing for Enterovirus and Parechovirus on Length of Hospitalization and Antimicrobial Use among Inpatients ≤6 Months of Age

Enterovirus (EV) and parechovirus (PeV) are leading viral causes of central nervous system (CNS) infection among hospitalized neonates and young infants, yet testing for PeV is not routinely performed. The goal of our study was to determine how EV and PeV CSF RT-PCR testing impacted the duration of antibiotic use and the length of hospitalization (LOS) in children ≤6 months old with suspected CNS infection. This retrospective cohort study at Children's Mercy Kansas City evaluated data from patients ≤6 months old for whom routine CSF EV and PeV reverse transcription-PCR (RT-PCR) testing was performed during January 2011 to December 2018. Electronic data were abstracted from the electronic medical record, including demographics, systemic antimicrobial use, imaging data, herpes simplex virus (HSV) testing, and overall hospital charges. Among 1,926 patients, 345 (17.9%) were RT-PCR positive for EV and 172 (8.9%) were positive for PeV. A significantly shorter LOS was observed for patients with EV (51.6 h; P < 0.001) and PeV (66.3 h; P = 0.048) compared to patients that tested negative for both viruses (74.1 h). Discontinuation of empirical antibiotic therapy following test result availability occurred more frequently for PeV patients (57.8%; P = 0.03) and EV patients (65.4%; P < 0.001) than RT-PCR-negative patients (48.5%). Routine EV/PeV RT-PCR testing of cerebrospinal fluid (CSF) samples in children impacted care of hospitalized neonates and young infants. Rapid and prompt diagnosis has the potential to reduce antibiotic usage, length of stay, and patient charges.

Viruses Causing Aseptic Meningitis: A Tertiary Medical Center Experience With a Multiplex PCR Assay

Background: Central nervous system (CNS) infection is associated with high rates of morbidity and mortality, and despite advancements in molecular testing, aseptic meningitis remains challenging to diagnose. Aseptic meningitis cases are often underreported worldwide, which impacts the quality of patient care. Therefore, we aimed to assess the results of BioFire® FilmArray® meningitis/encephalitis (ME) PCR panel, clinical characteristics, and etiologies of aseptic meningitis patients.

Methods: From January 2018 to January 2020, all pediatric and adult patients in a large tertiary medical center who underwent lumbar puncture and cerebrospinal fluid (CSF) testing by a ME multiplex PCR panel and who fit the aseptic meningitis definition were retrospectively reviewed.

Results: Data were reviewed from 1,607 patients; 240 met the inclusion criteria (54.6% males; 68.8% <4 years of age). The rate of detected viral causes of aseptic meningitis was 40.4%; therefore, 59.6% of the patients remained with unidentified etiology. Among the identified viral meningitis, enterovirus and human herpesvirus 6 (HHV-6) were the most common (25 and 7.9%, respectively). The median length of hospital stay was 6 days, and it was longer in patients with unidentifiable aseptic meningitis (p < 0.0001).

Conclusion: Aseptic meningitis is common among suspected meningitis patients, but most cases remained of unknown etiology. The most common identified viruses were enterovirus followed by HHV-6, and there is predominance in males and the pediatric age group. These results highlight that further research is needed to identify other etiologies and possible additional viral pathogens for aseptic meningitis in the current diagnostic methods.

Differential Diagnosis and Hospital Emergency Management for Fastlane Treatment of Central Nervous System Infection Under the COVID-19 Epidemic in Changsha, China

Importance: Corona virus disease 2019 (COVID-19) has long latent period, strong infectivity, and non-specific symptoms and signs in the upper respiratory tract. Some initial neurological symptoms appear, including dizziness, headache, seizures, slurred speech, disturbance of consciousness, and limb paralysis among a few COVID-19 patients, which share similar manifestations with central nervous system (CNS) infection. Improving the diagnostic efficiency of suspected CNS infection patients on the basis of preventing and controlling COVID-19 plays a key role in preventing nosocomial and cross infections. This study intends to formulate a hospital emergency management system of fastlane treatment of CNS infection for epidemic prevention and control, aiming at providing references and guidelines for the government and medical institutions to improve the efficiency of treating CNS infection patients in the clinical practice during COVID-19.

Observations: This study formulated a framework of a fastlane treatment of CNS infection based on the cooperation of resources and experience, aiming at the key and difficult problems faced by the hospital emergency management system during the COVID-19 outbreak in Changsha, China. The main problem of formulating the hospital emergency management system is efficiently identifying whether CNS infection was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The framework improves the efficiency of diagnosing and treating CNS infections by standardizing the diagnosis and treatment process of patients in emergency observation and strengthening the management of inpatient wards, aiming at assisting medical staff during clinical practice.

Conclusions and Relevance: The hospital emergency management system of a fastlane treatment of CNS infection for epidemic prevention and control of the COVID-19 outbreak is a professional and multisystem project, which needs the cooperation of various resources and the experience of clinical leadership.

Diagnostic accuracy of cerebrospinal fluid lactate in confirmed cases of acute bacterial meningitis in children

Objective:

To determine the diagnostic accuracy of cerebrospinal fluid lactate level in confirmed cases of acute bacterial meningitis in children

Methods:

This cross sectional study was conducted in the Department of Paediatrics, King Edward Medical University/ Mayo Hospital, Lahore from January to December 2018. A total of 250 children, between two months - 12 years of age, of both the genders, with suspected acute bacterial meningitis were included by non-probability consecutive sampling. Each child was subjected to lumbar puncture for biochemistry, cytology, culture, and lactate level. CSF lactate level of 1.1-2.4 mmol/L was taken as normal, and >2.4 mmol/L was taken as cut off for acute bacterial meningitis. All collected data was entered and analyzed in SPSS version 22. A 2 x 2 table was made to calculate diagnostic accuracy, sensitivity, specificity, positive and negative predictive value for CSF Lactate.

Results:

The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CSF lactate taking CSF culture as gold standard was 100%, 60.61%, 17.27%, 100% and 63.6% respectively, with kappa of 0.19 and p value of 0.000.

Conclusion:

At a cut off value of 2.4 mmol/L, cerebrospinal fluid lactate level has a high diagnostic accuracy for acute bacterial meningitis.

Viral Meningitis: A Pediatric Case Study

Meningitis is a significant viral, bacterial, or fungal infection of the meninges that cover and protect the brain and the spinal cord. Symptoms of meningitis may present rapidly or develop gradually over a period of days, manifesting with common prodromal flu-like symptoms of headache, photophobia, fever, nuchal rigidity, myalgias, and fatigue. Character and significance of symptoms vary by patient age. Symptoms of infection may improve spontaneously or worsen, becoming potentially lethal. Early recognition and treatment of meningitis are crucial to prevent morbidity and mortality. The case reviewed in this article focuses on viral meningitis in a pediatric patient that may be unrecognized or underreported because of indistinct symptoms. Epidemiology, pathophysiology, presentation, assessment techniques, diagnostics, clinical management, and health promotion relevant to viral meningitis are presented.

Secondary Headache: Current Update

PURPOSE

The purpose of this paper is to review some of the causes of secondary headache particularly focusing on the subcategories of secondary headache in the International Classification of Headache Disorders, 3rd edition, the clinical features of these headaches, and their associated features and management.

OVERVIEW

Headache attributed to trauma or injury to the head and/or neck, headache attributed to cranial or cervical vascular disorder, headache attributed to non-vascular intracranial disorder, headache attributed to a substance or its withdrawal, headache attributed to infection, headache attributed to disorder of homeostasis, and headache or facial pain attributed to disorder of the cranium, neck, eye, ears, nose, sinuses, teeth, mouth, or other facial or cervical structure are discussed in this paper.

DISCUSSION

Headache is a common symptom of multiple medical conditions. Although a minority of headache patients have a secondary basis for their headaches, it is important to identify clinical features of secondary headache disorders including both the headache and non-headache features of the condition, diagnose the secondary etiology correctly, and treat them appropriately.

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.

Enteroviral and herpes simplex virus central nervous system infections in infants < 90 days old: a Paediatric Investigators' Collaborative Network on Infections in Canada (PICNIC) study

Background

The relative contribution of viruses to central nervous system (CNS) infections in young infants is not clear. For viral CNS infections, there are limited data on features that suggest HSV etiology or on predictors of unfavorable outcome.

Methods

In this cross-sectional retrospective study, seven centers from the Pediatric Investigators Collaborative Network on Infections in Canada identified infants < 90 days of age with CNS infection proven to be due to enterovirus (EV) or herpes simplex virus (HSV) January 1, 2013 through December 31, 2014.

Results

Of 174 CNS infections with a proven etiology, EV accounted for 103 (59%) and HSV for 7 (4%). All HSV cases and 41 (40%) EV cases presented before 21 days of age. Four HSV cases (57%) and 5 EV cases (5%) had seizures. Three (43%) HSV and 23 (23%) EV cases lacked cerebrospinal fluid (CSF) pleocytosis. HSV cases were more likely to require ICU admission (p = 0.010), present with seizures (p = 0.031) and have extra-CNS disease (p < 0.001). Unfavorable outcome occurred in 12 cases (11% of all EV and HSV infections) but was more likely following HSV than EV infection (4 (57%) versus 8 (8%); p = 0.002).

Conclusions

Viruses accounted for approximately two-thirds of proven CNS infections in the first 90 days of life. Empiric therapy for HSV should be considered in suspected CNS infections in the first 21 days even in the absence of CSF pleocytosis unless CSF parameters are suggestive of bacterial meningitis. Neurodevelopmental follow-up should be considered in infants whose course of illness is complicated by seizures.

Implementation of the FilmArray ME panel in laboratory routine using a simple sample selection strategy for diagnosis of meningitis and encephalitis

Background

Infectious meningitis is a serious disease and patient outcome relies on fast and reliable diagnostics. A syndromic panel testing approach like the FilmArray ME can accelerate diagnosis and therefore decrease the time to pathogen specific therapy. Yet, its clinical utility is controversial, mainly because of a remaining uncertainty in correct interpretation of results, limited data on its performance on clinical specimens and its relatively high costs. The aim of this study was to analyze clinical performance of the assay in a real life setting at a tertiary university hospital using a pragmatic and simple sample selection strategy to reduce the overall cost burden.

Methods

Over a period of 18 months we received 4623 CSF samples (2338 hospitalizations, 1601 individuals). FilmArray ME analysis was restricted to CSF-samples with a high pretest probability of infectious meningitis, e.g. positive Gram-stain, samples in which leukocytes and/or bacteria were evident or urgent suspicion of infection was communicated by clinicians. N = 171 samples matched to our risk criteria and were subjected to FilmArray ME analysis. Those samples were also analyzed by reference methods: culture only (n = 45), PCR only (n = 20) or both methods (n = 106).

Results

56/171 (32.75%) were FilmArray ME positive. Bacterial pathogens were detected in 30/56 (53.57%), viral pathogens were detected in 27/56 (48.21%) and yeast DNA was detected in 1/56 (1.79%) of positive samples. Double detection occurred in 2/56 samples. In 52/56 (92.86%) FilmArray ME positive samples, results could be confirmed by the reference assays (sensitivity = 96.30%, specificity =96.58%).

Conclusion

The FilmArray ME assay is a fast and reliable diagnostic tool for the management of infectious meningitis and can easily be implemented in routine diagnostic workflows. However, correlation of test results and underlying clinical symptoms requires experienced users and the awareness of potentially false negative or false positive results. Moreover, considering the need for antimicrobial susceptibility testing, the use of molecular tests as a stand-alone diagnostic cannot be recommended.

Clinical characteristics and molecular epidemiology of children with meningitis in Tehran, Iran: a prospective study

The molecular epidemiology of meningitis in children is unclear in Iran, and data are scarce. We aimed to characterize its clinical and paraclinical features as well as to determine the distribution of genotype/capsular types of common bacterial meningitis agents in children in Iran. All children suspected to have meningitis aged 4 days to 15 years were enrolled onto a prospective cross-sectional study from January 2015 to September 2017. Diagnostic values of clinical features, cerebrospinal fluid and serum parameters were evaluated independently and in combination with each other by multivariate logistic regression to develop a diagnostic rule. Genotype/capsular types of all the isolates were determined by targeting serotype-specific genes with uniplex or multiplex PCR. Among 119 patients suspected of having meningitis, 43 had bacterial meningitis, 19 aseptic and one tuberculous; and there were 56 nonmeningitis cases (NMC). Presentation of four features at the same time-cerebrospinal fluid white blood cell count, protein, polymorphonuclear leukocytes and serum C-reactive protein-revealed 100% sensitivity and 86.4% specificity for diagnosis of bacterial meningitis. Haemophilus influenzae type b (60%), Streptococcus pneumoniae serotype 3 (28.5%) and Neisseria meningitidis B (63.5%) were the most prevalent serotypes. This study demonstrated that a well-designed combination of clinical and paraclinical features is useful, but these combinations are not good enough to be relied on as stand-alone exclusionary tests for the diagnosis of bacterial meningitis. In addition, public immunization of infants with the most prevalent bacterial meningitis serotypes is recommended.

Early clinical management of acute CNS infections: a prospective cohort study

Aim: To explore early management and clinical predictors of patients with suspected CNS infections. Methods: In a prospective cohort study of 125 adult patients with suspected CNS infections, clinical features and early management time points were compared between groups with and without confirmed CNS infections. Results: The door-to-lumbar puncture time was associated with the initial Glasgow Coma Scale score, the confirmed diagnosis and the time to change empirical treatment. Multivariate analysis indicated that the initial Glasgow Coma Scale score was an independent risk factor for prognosis. Conclusion: Lumbar puncture plays a crucial role in early management of CNS infections. Patients with CNS infection who have disturbances of consciousness should receive particular attention.

Central nervous system (CNS) enterovirus infections: A single center retrospective study on clinical features, diagnostic studies, and outcome

Enteroviruses (EV) are responsible for a large number of meningoencephalitis cases, especially in children. The objective of this study was to identify modes of diagnosis including the significance of respiratory and cerebrospinal fluid samples, associated clinical characteristics, inpatient management, and outcome of individuals with EV infections of the central nervous system (CNS). Electronic medical records of individuals with enterovirus infections of the CNS who presented to the Columbia University Irving Medical Center and Children's Hospital of New York between January 1, 2012 and December 31, 2017 were reviewed retrospectively for demographic, epidemiological, and clinical data. The median age overall was 1.7 months (interquartile range 14 years) and most (62.4%) were male. The majority of CNS infections presented as meningitis (95.7%) and occurred in the summer (45.2%) and fall seasons (37.6%). Eighty-five cases (91.4%) demonstrated EV positivity in cerebrospinal fluid, thirty cases (32.3%) exhibited both cerebrospinal fluid and respiratory positivity, and eight cases (8.6%) exhibited respiratory positivity with coinciding neurological findings. Eighty-nine individuals overall (95.7%) received antibiotics and 37 (39.8%) received antiviral treatment. All surviving individuals had favorable Modified Rankin Scores (MRS) within the zero to two ranges upon discharge. Testing respiratory samples in addition to cerebrospinal fluid was found to be an important diagnostic tool in EV-associated cases. While clinical outcomes were favorable for an overwhelming majority of cases, etiological understanding of CNS infections is essential for identifying ongoing and changing epidemiological patterns and aid in improving the diagnosis and treatment.

Genome-Wide miRNA Analysis Identifies Potential Biomarkers in Distinguishing Tuberculous and Viral Meningitis

Tuberculous meningitis (TBM) is the most common and severe form of central nervous system tuberculosis. Due to the non-specific clinical presentation and lack of efficient diagnosis methods, it is difficult to discriminate TBM from other frequent types of meningitis, especially viral meningitis (VM). In order to identify the potential biomarkers for discriminating TBM and VM and to reveal the different pathophysiological processes between TBM and VM, a genome-wide miRNA screening of PBMCs from TBM, VM, and healthy controls (HCs) using microarray assay was performed (12 samples). Twenty-eight differentially expressed miRNAs were identified between TBM and VM, and 11 differentially expressed miRNAs were identified between TBM and HCs. The 6 overlapping miRNAs detected in both TBM vs. VM and TBM vs. HCs were verified by qPCR analysis and showed a 100% consistent expression patterns with that in microarray test. Statistically significant differences of 4 miRNAs (miR-126-3p, miR-130a-3p, miR-151a-3p, and miR-199a-5p) were further confirmed in TBM compared with VM and HCs in independent PBMCs sample set (n = 96, P < 0.01). Three of which were also showed significantly different between TBM and VM in CSF samples (n = 70, P < 0.05). The receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve (AUC) of these 4 miRNAs in PBMCs were more than 0.70 in discriminating TBM from VM. Combination of these 4 miRNAs could achieve better discriminative capacity [AUC = 0.893 (0.788-0.957)], with a sensitivity of 90.6% (75.0-98.0%), and a specificity of 86.7% (69.3-96.2%). Additional validation was performed to evaluate the diagnostic panel in another independent sample set (n = 49), which yielded a sensitivity of 81.8% (9/11), and specificity of 90.0% (9/10) in distinguishing TBM and VM, and a sensitivity of 81.8% (9/11), and a specificity of 84.6% (11/13) in discriminating TBM from other non-TBM patients. This study uncovered the miRNA profiles of TBM and VM patients, which can facilitate better understanding of the pathogenesis involved in these two diseases and identified 4 novel miRNAs in distinguishing TBM and VM.

Human adenovirus meningoencephalitis: a 3-years' overview

Human adenovirus (HAdV) has been recognized as a significant viral pathogen implicated in neurological diseases, particularly in immunocompromised patients. However, its involvement in meningoencephalitis remains unclear. The aim of this study was to investigate HAdV and other viral co-infections in the cerebrospinal fluid (CSF) of patients suspected of having either meningoencephalitis or encephalitis. A total of 373 CSF samples from patients under clinical suspicion of neurological viral infection were included in this study. HAdV was investigated by conventional or multiplex real-time PCR, for different time periods. The frequency of HAdV central nervous system (CNS) infection was 1.08%, predominating in female patients with a predisposing condition, and presented with HAdV encephalitis. HAdV CNS infection was found to occur during the months of autumn and winter. The frequency of HAdV detected in CSF positive samples increased after the change in the diagnostic method from conventional to multiplex real-time PCR. There were no specific NMRI or EEG characteristics and two CSF samples with HAdV encephalitis had normal CSF WBC count. There were two cases of co-infection with HIV; no other co-infections with enterovirus or herpes family viruses were detected. All patients had good outcome. Although HAdV is rarely observable in CNS infectious syndromes, it must be investigated particularly in immunocompromised patients.

Performance of lactate in discriminating bacterial meningitis from enteroviral meningitis

The cytological and biochemical examination of cerebrospinal fluid (CSF) has been used for the presumed diagnosis of bacterial meningitis until the final microbiological results are achieved. We assessed the ability of CSF lactate in comparison with other CSF parameters to discriminate bacterial and enteroviral community acquired meningitis. We included 1,187 CSF samples of acute community-acquired meningitis, being 662 cases of bacterial and 525 of enteroviral meningitis. Lactate concentration (mg/dL), leukocyte count/mm³, protein (mg/dL), and glucose (mg/dL) were compared between bacterial and viral meningitis. Receiver operator characteristic (ROC) curves were used to assess diagnostic performance. CSF leukocytes, CSF protein and CSF lactate were significantly higher in bacterial meningitis cases (P<0.0001). CSF glucose was significantly lower in bacterial meningitis cases (P<0.0001). CSF lactate showed the best predictive ability with an area under the curve of 0.944 (95% CI 0.929 – 0.959). Considering a cut off of CSF lactate of 30 mg/dL, the sensitivity and specificity for bacterial meningitis were 84.1% and 99%, respectively. In the cytological and biochemical CSF analysis, CSF lactate was the most accurate marker for bacterial meningitis.

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.

Community-acquired acute meningitis and encephalitis: a narrative review

Meningitis and encephalitis are medical emergencies. Patients need prompt evaluation and immediate empiric therapy to reduce the likelihood of fatal outcomes and chronic neurological sequelae. Conjugate bacterial vaccines have significantly reduced the incidence of bacterial meningitis, especially in children. As the results of changes in patterns of bacterial drug sensitivity, ceftriaxone is now part of the recommended empiric treatment for bacterial meningitis and should be administered as early as possible. Neuroimaging delays the treatment of meningitis and is not needed in most cases. Adjunctive corticosteroid therapy is of benefit for many patients with meningitis and should be initiated in most adults before antibiotic therapy. Molecular testing can assist the specific diagnosis of encephalitis and should be based on the exposure history and geographic risk factors relevant to the patient, but non-infectious causes of encephalitis are also common. Empiric therapy for encephalitis should be directed at the most frequently identified infectious pathogen, herpes simplex virus type 1 (ie, intravenous aciclovir). Vaccines can protect against the major pathogens of childhood infections (measles, mumps, rubella, polio, varicella viruses), influenza viruses, and exotic pathogens that cause meningitis and encephalitis (rabies, Japanese encephalitis, dengue, yellow fever, tick-borne encephalitis viruses, Mycobacterium tuberculosis).

Infections of the Nervous System

Microorganisms can affect the entire neuraxis, producing a variety of neurologic complications that frequently entail prolonged hospitalizations and complicated treatment regimens. The spread of pathogens to new regions and the reemergence of opportunistic organisms in immunocompromised patients pose increasing challenges to health care professionals. Because rapid diagnosis and treatment may prevent long-term neurologic sequelae, providers should approach these diseases with a structured, neuroanatomic framework, incorporating a thorough history, examination, laboratory analysis, and neuroimaging in their clinical reasoning and decision-making.

Cerebrospinal fluid cytology in nonmalignant aseptic meningeal disorders

Cerebrospinal fluid cytology examination is a common and reliable primary and/or complementary procedure for the diagnosis of central nervous system (CNS) disorders. This review provides an update of aseptic meningeal disorders that may be encountered in cytopathology practice. The article covers the cytological findings and helpful ancillary studies needed of nonmalignant aseptic CNS disorders such as viral, bacterial, fungal and parasitic infections, and other noninfectious diseases, such as Mollaret's meningitis (recurrent benign lymphocytic meningitis), Guillain-Barré syndrome, multiple Sclerosis, subarachnoid haemorrhage, and drug-induced disorders.