Acute bacterial meningitis

Clinical characteristics and outcomes of acute bacterial meningitis in adults at a tertiary university hospital in Thailand

The epidemiology of acute bacterial meningitis varies among settings, areas, and times. This study aimed to determine the clinical characteristics, the causative organisms and their antibiotic susceptibility, and the outcomes of patients with acute bacterial meningitis in Thai adults. This retrospective study included hospitalized patients aged ≥18 years diagnosed with acute bacterial meningitis at Siriraj Hospital during January 2002-December 2016. Of 390 patients, the median age was 48 years, 51% were male, and 80% had at least 1 underlying illness. Over half (54%) of patients had community-acquired bacterial meningitis (CBM), and 46% had nosocomial bacterial meningitis (NBM). The triad of acute bacterial meningitis (fever, headache, and neck stiffness) was found in 46% of CBM and 15% of NBM (P < .001). The causative organisms were identified in about half (53%) of patients. Most study patients (73%) received antibiotic treatment before the CSF collection. Causative organisms were identified more frequently in CBM (P < .001). Gram-positive cocci were more prevalent in CBM (P < .001), whereas Gram-negative bacilli were more common in NBM (P < .001). Streptococcus agalactiae (29%), Streptococcus pneumoniae (12%), and Streptococcus suis (11%) were most common in CBM, and all of them were sensitive to third-generation cephalosporins. Acinetobacter baumannii (19%), Klebsiella pneumoniae (16%), and Staphylococcus aureus (11%) were the most common organisms in NBM, and antibiotic-resistant isolates were frequently found among these organisms. Ceftriaxone monotherapy and meropenem plus vancomycin were the most common empiric antibiotic in CBM and NBM, respectively. Mortality was 19% among CBM and 23% among NBM (P = .338). HIV infection, alcoholism, pneumonia, shock, and disseminated intravascular coagulation were independent predictors of mortality. Mortality remains high among adults with acute bacterial meningitis in Thailand. A clinical practice guideline for acute bacterial meningitis should be developed that is based on local epidemiology and microbiology data.

Daptomycin for the treatment of acute bacterial meningitis: a narrative review

BACKGROUND

There is a growing interest in the utilization of daptomycin for the treatment of multi-drug resistant, Gram-positive infections. Pharmacokinetic studies suggest that daptomycin could penetrate into the cerebrospinal fluid, albeit to a small extent. The objective of this review was to evaluate the available clinical evidence for daptomycin use in acute bacterial meningitis of both pediatric and adult patients.

METHODS

Electronic databases were searched up to June 2022 for studies published on the topic. The inclusion criteria were met if the study reported the use of intravenous daptomycin (more than a single dose) for the treatment of diagnosed acute bacterial meningitis.

RESULTS

A total of 21 case reports were identified that met the inclusion criteria. These suggest that daptomycin could be safe and effective alternative in achieving clinical cure of meningitis. In these studies, daptomycin was used in the event of treatment failure, patient intolerance, or bacterial resistance to first-line agents.

CONCLUSIONS

Daptomycin has potential to be an alternative to standard care for meningitis caused by Gram-positive bacteria in the future; however, more robust research is required to establish an optimal dosing regimen, duration of therapy, and place in therapy for the management of meningitis.

Changes in the incidence of acute bacterial meningitis caused by Streptococcus pneumoniae and the implications of serotype replacement in children in Colombia after mass vaccination with PCV10

INTRODUCTION

Acute bacterial meningitis (ABM) is a public health problem. The disease has reemerged after the introduction of pneumococcal conjugate vaccines (PCVs) due to an increase in serotypes that are not covered. The objective was to determine the changes in the disease incidence before and after the introduction of the 10-valent vaccine (PCV10) in Colombia.

METHODS

This multicenter study was conducted in 17 hospitals in Colombia. Data were collected from January 2008 to December 2019 in 10 hospitals in Bogotá and from January 2017 to December 2019 in seven hospitals in Cali, Medellín and Cartagena. The data were grouped into three periods: 2008-2011, 2012-2015, and 2016-2019.

RESULTS

Of the 706 cases of invasive pneumococcal disease, 81 (11.4%) corresponded to meningitis. The relative incidence in Bogotá in the first period was 0.6 per 100,000 patients ≤ 5 years, decreased to 0.4 per 100,000 patients ≤ 5 years in the second period and increased in the third period to 0.7 per 100,000 patients ≤ 5 years. Serotypes covered by PCV10 decreased from 75 to 9.1%, with Spn19A (31.8%) and Spn34 (13.6%) emerging in the third period. Increased resistance to penicillin (13 to 37%) and to ceftriaxone (5.9 to 16%) was due to the emergence of multidrug-resistant Spn19A. The total mortality rate was 23.5% and increased from 12 to 33%.

CONCLUSIONS

ABM due to pneumococcus has high morbidity and mortality rates. Reemergence of the disease has been observed due to the inclusion of polymerase chain reaction (PCR) for diagnosis and replacement of circulating serotypes after the introduction of PCV10, with an increase in Spn19A, which causes death and exhibits antimicrobial resistance. Continued surveillance is needed.

Factors associated with mortality in intracranial infection patients admitted to pediatric intensive care unit: A retrospective cohort study

Background

Intracranial infection is a major cause of emergency and death in children. To assist clinical decision-making in patient management, we conducted a study about factors associated with mortality. This study aimed to evaluate factors associated with mortality in pediatric patients with intracranial infection.

Methods

We performed a cohort retrospective study in our tertiary hospital to evaluate the outcomes of patients admitted to the pediatric intensive care unit (PICU) from 2014 to 2018. The Chi-square test was performed to determine the significance of the predictor, and p < 0.05 was considered to indicate a statistically significant result. We used multivariate logistic regression to determine relative risk (RR) with 95% confidence interval (CI).

Results

We recruited 112 patients who were admitted to the PICU of our tertiary hospital. A total of 38.4% were diagnosed with encephalitis, 9.8% meningitis and 51.8% meningoencephalitis. Of the 112 patients who met the inclusion criteria, 28 (25%) patients died in the PICU. The need of mechanical ventilation support variable had a statistically significant association with mortality (RR 22.76; 95% CI: 3.88–51.45).

Conclusion

Recognition of conditions that exacerbate intracranial infection in children needs to be done as early as possible. Moreover, the need of mechanical ventilation support in the PICU needs more attention.

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Intracranial infection is a major cause of emergency and death in children.

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Recognition of conditions that exacerbate intracranial infection.

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The need of mechanical ventilation support in the pediatric intensive care unit.

Three-Dimensional Printability of an ECM-Based Gelatin Methacryloyl (GelMA) Biomaterial for Potential Neuroregeneration

The current study introduces two novel, smart polymer three-dimensional (3D)-printable interpenetrating polymer network (IPN) hydrogel biomaterials with favorable chemical, mechanical, and morphological properties for potential applications in traumatic brain injury (TBI) such as potentially assisting in the restoration of neurological function through closure of the wound deficit and neural tissue regeneration. Additionally, removal of injury matter to allow for the appropriate scaffold grafting may assist in providing a TBI treatment. Furthermore, due to the 3D printability of the IPN biomaterials, complex structures can be designed and fabricated to mimic the native shape and structure of the injury sight, which can potentially assist with neural tissue regeneration after TBI. In this study, a peptide-only approach was employed, wherein collagen and elastin in a blend with gelatin methacryloyl were prepared and crosslinked using either Irgacure or Irgacure and Genipin to form either a semi or full IPN hydrogel 3D-printable neuromimicking platform system, respectively. The scaffolds displayed favorable thermal stability and were amorphous in nature with high full width at half-maximum values. Furthermore, no alteration to the peptide secondary structure was noted using Fourier transform infrared spectroscopy. The IPN biomaterials have a stiffness of around 600 Pa and are suitable for softer tissue engineering applications-that is, the brain. Scanning electron micrographs indicated that the IPN biomaterials had a morphological structure with a significant resemblance to the native rat cortex. Both biomaterial scaffolds were shown to support the growth of PC12 cells over a 72 h period. Furthermore, the increased nuclear eccentricity and nuclear area were shown to support the postulation that the IPN biomaterials maintain the cells in a healthy state encouraging cellular mitosis and proliferation. The Genipin component of the full IPN was further shown to exhibit antimicrobial properties and this suggests that Genipin can prevent the growth of pathogens associated with postsurgical brain infections. In addition to these findings, the study presents an anomaly, wherein the full IPN is found to be more brittle than the semi IPN, a finding that is in contradiction with the literature. This research, therefore, contributes to the collection of potential biomaterials for TBI applications coupled with 3D printing and can assist in the progression of neural treatments toward patient-specific scaffolds through the development of custom scaffolds.

The Epidemiology and Outcomes of Meningitis among Iranian Children in a Period of 10 Years

Background:

One of the important causes of childhood febrile illness is meningitis. It causes bacterial, viral, fungal, parasitic, and non-infectious agents. Pediatric bacterial meningitis is one of the most important causes of infant mortality, especially in premature infants. This study aimed to identify the outcome and mortality of children with meningitis.

Methods and Materials:

All children with meningitis in the Pediatric Department of Rasool Akram Hospital from December 23, 2007, to December 16, 2017, were included. Signs and symptoms (fever, consciousness, neck rigidity, and seizure) were collected and Cerebrospinal fluid analysis in children was made. Based on these findings, patients were divided into two groups, which include bacterial and non-bacterial meningitis. Then we recalled all families and examined them to discover the child’s outcome and complications at least after two years.

Results:

During the ten-year study period, 202 children were included in the study. Patients aged less than 12 months were found to be more frequently affected. Fever was the most common presentation (83.4%) followed by seizure (51.5%) and vomiting (49%). 119 (58.9%) of the patients were male and 83 (41.1%) were female. Definite bacterial meningitis was the final diagnosis in 35.6% (72) of patients (mean age 34.1± 48.3 months), and non-bacterial meningitis was diagnosed in 64.4% (130) of cases (mean age 46.3± 52.4 months). The most common organism in bacterial meningitis (by all methods) was Streptococcus pneumonia. Among children, 187 (92.1%) were survivors and 15 (%7.9) were non-survivors. Neurological sequelae such as motor deficit and epilepsy were identified in 9 (4.8%) and 5 (2.6%) subjects, respectively, and that they were all caused by bacterial meningitis. There was no death or neurological sequelae observed during follow-up in children with non-bacterial meningitis. Gender, age, signs and symptoms of patients at the time of admission were not significantly different between the bacterial and non-bacterial meningitis groups (p>0.05). Hydrocephalus, CSF characteristic, morbidity and mortality were significantly different between the bacterial and non-bacterial meningitis groups.

Conclusion:

This study showed that elevated LDH and low glucose levels in CSF are characteristic of bacterial meningitis. Increased LDH is significantly related to death in children (P-value > 0.001) with meningitis. Beneficial empirical antibiotics and sufficient follow-up by parents cause good prognosis in children with meningitis. Also in a child with fever and seizure, we should think of meningitis, even though in the absence of positive neurological examinations. It seems that increased CSF LDH, elevated CSF protein and age under one year are significant mortality risk factors in children with meningitis.

A Rare Mutation in SPLUNC1 Affects Bacterial Adherence and Invasion in Meningococcal Disease

Background

Neisseria meningitidis (Nm) is a nasopharyngeal commensal carried by healthy individuals. However, invasive infections occurs in a minority of individuals, with devastating consequences. There is evidence that common polymorphisms are associated with invasive meningococcal disease (IMD), but the contributions of rare variants other than those in the complement system have not been determined.

Methods

We identified familial cases of IMD in the UK meningococcal disease study and the European Union Life-Threatening Infectious Disease Study. Candidate genetic variants were identified by whole-exome sequencing of 2 patients with familial IMD. Candidate variants were further validated by in vitro assays.

Results

Exomes of 2 siblings with IMD identified a novel heterozygous missense mutation in BPIFA1/SPLUNC1. Sequencing of 186 other nonfamilial cases identified another unrelated IMD patient with the same mutation. SPLUNC1 is an innate immune defense protein expressed in the nasopharyngeal epithelia; however, its role in invasive infections is unknown. In vitro assays demonstrated that recombinant SPLUNC1 protein inhibits biofilm formation by Nm, and impedes Nm adhesion and invasion of human airway cells. The dominant negative mutant recombinant SPLUNC1 (p.G22E) showed reduced antibiofilm activity, increased meningococcal adhesion, and increased invasion of cells, compared with wild-type SPLUNC1.

Conclusions

A mutation in SPLUNC1 affecting mucosal attachment, biofilm formation, and invasion of mucosal epithelial cells is a new genetic cause of meningococcal disease.

Psychiatric Disabilities and Other Long-term Consequences of Childhood Bacterial Meningitis

BACKGROUND

Bacterial meningitis is known to cause hearing impairments and neurologic deficits; however, less is known regarding psychiatric disabilities. In this study, we assessed psychiatric disabilities and other long-term consequences of childhood bacterial meningitis.

METHODS

From a previously validated dataset, we selected children having had bacterial meningitis. We then reviewed medical records and child health records from discharge onwards to identify disabilities. We calculated the occurrence of disabilities with a 95% confidence interval (CI), and we used a χ test to assess possible individual risk factors associated with occurrence of disabilities.

RESULTS

Of the 80 children included in this study, permanent disabilities not attributed to preexisting diseases were noted in 56% (CI: 45-67) during the mean observation period of 19 years and 2 months. Psychiatric disease was diagnosed in 30% (CI: 21-41), and another 5% (CI: 2-13) were under ongoing investigations for symptoms of psychiatric disease. Hearing impairments affected at least 30% (CI: 20-40), and neurologic deficits affected at least 23% (CI: 15-34). While other disabilities were often detected within the first year, psychiatric disabilities were detected after a mean time period of 14 years (CI: 11:1-16:11). Although some associations were noted, no individual risk factor was able to predict the occurrence of disabilities.

CONCLUSIONS

Psychiatric disabilities affect more than one-third of survivors and are among the most common long-term consequence of childhood bacterial meningitis. Late discovery and predictive difficulties call for a revision of current guidelines to include a specific long-term strategy for detecting psychiatric disabilities.

MeningiSSS: A New Predictive Score to Support Decision on Invasive Procedures to Monitor or Manage the Intracerebral Pressure in Children with Bacterial Meningitis

BACKGROUND

Knowing the individual child's risk is highly useful when deciding on treatment strategies, especially when deciding on invasive procedures. In this study, we aimed to develop a new predictive score for children with bacterial meningitis and compare this with existing predictive scores and individual risk factors.

METHODS

We developed the Meningitis Swedish Survival Score (MeningiSSS) based on a previous systematic review of risk factors. From this, we selected risk factors identified in moderate-to-high-quality studies that could be assessed at admission to the hospital. Using data acquired from medical records of 101 children with bacterial meningitis, we tested the overall capabilities of the MeningiSSS compared with four existing predictive scores using a receiver operating characteristic curve (ROC) analysis to assert the area under the curve (AUC). Finally, we tested all predictive scores at their cut-off levels using a Chi-square test. As outcome, we used a small number of predefined outcomes; in-hospital mortality, 30-day mortality, occurrence of neurological disabilities at discharge defined as Pediatric Cerebral Performance Category Scale category two to five, any type of complications occurring during the hospital stay, use of intensive care, and use of invasive procedures to monitor or manage the intracerebral pressure.

RESULTS

For identifying children later undergoing invasive procedures to monitor or manage the intracerebral pressure, the MeningiSSS excelled in the ROC-analysis (AUC = 0.90) and also was the only predictive score able to identify all cases at its cut-off level (25 vs 0%, p < 0.01). For intensive care, the MeningiSSS (AUC = 0.79) and the Simple Luanda Scale (AUC = 0.75) had the best results in the ROC-analysis, whereas others performed less well (AUC ≤ 0.65). Finally, while none of the scores' results were significantly associated with complications, an elevated score on the MeningiSSS (AUC = 0.70), Niklasson Scale (AUC = 0.72), and the Herson-Todd Scale (AUC = 0.79) was all associated with death.

CONCLUSIONS

The MeningiSSS outperformed existing predictive scores at identifying children later having to undergo invasive procedures to monitor or manage the intracerebral pressure in children with bacterial meningitis. Our results need further external validation before use in clinical practice. Thus, the MeningiSSS could potentially be helpful when making difficult decisions concerning intracerebral pressure management.

A prospective study on the clinical profile and outcome of meningoencephalitis in adults in a South Indian tertiary care centre

BACKGROUND

Although there are numerous studies on meningitis and encephalitis separately, literature on meningoencephalitis is sparse. In this study we analysed the clinical profile of meningoencephalitis and its clinical outcome.

METHODS

Fifty adults diagnosed with meningoencephalitis from July 2014 to July 2015 in a tertiary care hospital in South India were studied prospectively and their clinical presentation, aetiology and outcome were analysed.

RESULTS

Among 50 patients, 33 (66%) were male; 39 (78%) were <50 years of age. Fever was the most common presenting symptom in 41 out of 50 patients (82%), followed by headache (74%) and altered sensorium (62%); only 18 patients (36%) had all three classical symptoms. Twenty-eight out of 50 patients (56%) did not have neck stiffness. A majority of patients had acute-to-subacute clinical presentation. Mycobacterium tuberculosis was identified in 58% (29 out of 50). Forty-seven patients (94%) recovered completely.

CONCLUSION

Tuberculosis was the most common cause of meningoencephalitis in the studied population, often with subacute presentation, and outcome was good with early institution of antituberculous therapy.

Mediators and Biomarkers of Inflammation in Meningitis: Cytokine and Peptidome Profiling of Cerebrospinal Fluid

Differential diagnosis of bacterial and viral meningitis is an urgent problem of the modern clinical medicine. Early and accurate detection of meningitis etiology largely determines the strategy of its treatment and significantly increases the likelihood of a favorable outcome for the patient. In the present work, we analyzed the peptidome and cytokine profiles of cerebrospinal fluid (CSF) of 17 patients with meningitis of bacterial and viral etiology and of 20 neurologically healthy controls. In addition to the identified peptides (potential biomarkers), we found significant differences in the cytokine status of the CSF of the patients. We found that cut-off of 100 pg/ml of IL-1β, TNF, and GM-CSF levels discriminates bacterial and viral meningitis with 100% specificity and selectivity. We demonstrated for the first time the reduction in the level of two cytokines, IL-13 and GM-CSF, in the CSF of patients with viral meningitis in comparison with the controls. The decrease in GM-CSF level in the CSF of patients with viral meningitis can be explained by a disproportionate increase in the levels of cytokines IL-10, IFN-γ, and IL-4, which inhibit the GM-CSF expression, whereas IL-1, IL-6, and TNF activate it. These observations suggest an additional approach for differential diagnosis of bacterial and viral meningitis based on the normalized ratio IL-10/IL-1β and IL-10/TNF > 1, as well as on the ratio IFN-γ/IL-1β and IFN-γ/TNF < 0.1. Our findings extend the panel of promising clinical and diagnostic biomarkers of viral and bacterial meningitis and reveal opposite changes in the cytokine expression in meningitis due to compensatory action of pro- and antiinflammatory factors.

C-REACTIVE PROTEIN (CRP) AS A SUPPORTING MARKER OF ANTIBIOTIC EFFECTIVENESS ON CENTRAL NERVOUS SYSTEM (CNS) INFECTIONS

Infection of the central nervous system in pediatric patients have a high mortality as well as acute and chronic neurological sequelae. Signs of the disease are unclear, so cerebrospinal fluid (CSF) test is used as a gold standard for diagnosis, but the investigation has faced many obtacles. Empiric antibiotic therapy is the key factor in reducing morbidity and mortality. Microbiological culture result is obtained within 5-7 days. The effectiveness of empirical antibiotic use is questionable. Therefore, other investigations are conducted to determine the effectiveness of antibiotics by using one marker, the CRP. This study was to analyze CRP level in supporting antibiotic therapy effectiveness in pediatric patients with central nervous system (CNS) infections. A prospective cohort study was conducted to determine the relationship of CRP with other parameters, including clinical, microbiological and laboratory, in pediatric patients with central nervous system infections. Patients meeting blood samples criteria were taken before (H0), the third day (H3) and the fifth day (H5) after antibiotics administration. This study involved 10 patients with central nervous system infections (meningoencephalitis, encephalitis and encephalitis with cerebral edema). Six patients were male, with ages less than a year. Antibiotic treatment effectiveness was associated with improved condition of the patients' CRP level. It was 3.558 ±3.196 before (H0), 3.878±2.813 on the third day (H3) and 3.891±2.204 on the fifth day (H5) after antibiotic administration. Leukocyte levels were 13.680±1.660 before (H0), 17.832±7.213 on the third day (H5), and 10.546±3.671 on the fifth day (H5) after antibiotic administration. Pearson's correlation test analysis performed on CRP and WBC parameters showed H0 p=0.981, CRP and WBC H3 p=0.621, while CRP and WBC H5 obtained significance p=0.644. There was no significant correlation observed between CRP and WBC parameters before and after antibiotic administration. In conclusion, there was no correlation of CRP levels with clinical, laboratory and micobiological parameters in patients with central nervous system infections.

Bacterial agents causing meningitis during 2013-2014 in Turkey: A multi-center hospital-based prospective surveillance study

This is an observational epidemiological study to describe causes of bacterial meningitis among persons between 1 month and 18 y of age who are hospitalized with suspected bacterial meningitis in 7 Turkish regions. covering 32% of the entire population of Turkey. We present here the results from 2013 and 2014. A clinical case with meningitis was defined according to followings: any sign of meningitis including fever, vomiting, headache, and meningeal irritation in children above one year of age and fever without any documented source, impaired consciousness, prostration and seizures in those < 1 y of age. Single tube multiplex PCR assay was performed for the simultaneous identification of bacterial agents. The specific gene targets were ctrA, bex, and ply for N. meningitidis, Hib, and S. pneumoniae, respectively. PCR positive samples were recorded as laboratory-confirmed acute bacterial meningitis. A total of 665 children were hospitalized for suspected acute meningitis. The annual incidences of acute laboratory-confirmed bacterial meningitis were 0.3 cases / 100,000 population in 2013 and 0.9 cases/100,000 in 2014. Of the 94 diagnosed cases of bacterial meningitis by PCR, 85 (90.4%) were meningococcal and 9 (9.6%) were pneumococcal. Hib was not detected in any of the patients. Among meningococcal meningitis, cases of serogroup Y, A, B and W-135 were 2.4% (n = 2), 3.5% (n = 3), 32.9% (n = 28), and 42.4% (n = 36). No serogroup C was detected among meningococcal cases. Successful vaccination policies for protection from bacterial meningitis are dependent on accurate determination of the etiology of bacterial meningitis. Additionally, the epidemiology of meningococcal disease is dynamic and close monitoring of serogroup distribution is comprehensively needed to assess the benefit of adding meningococcal vaccines to the routine immunization program.

A structural insight into the P1S1 binding mode of diaminoethylphosphonic and phosphinic acids, selective inhibitors of alanine aminopeptidases

N'-substituted 1,2-diaminoethylphosphonic acids and 1,2-diaminoethylphosphinic dipeptides were explored to unveil the structural context of the unexpected selectivity of these inhibitors of M1 alanine aminopeptidases (APNs) versus M17 leucine aminopeptidase (LAP). The diaminophosphonic acids were obtained via aziridines in an improved synthetic procedure that was further expanded for the phosphinic pseudodipeptide system. The inhibitory activity, measured for three M1 and one M17 metalloaminopeptidases of different sources (bacterial, human and porcine), revealed several potent compounds (e.g., Ki = 65 nM of 1u for HsAPN). Two structures of an M1 representative (APN from Neisseria meningitidis) in complex with N-benzyl-1,2-diaminoethylphosphonic acid and N-cyclohexyl-1,2-diaminoethylphosphonic acid were determined by the X-ray crystallography. The analysis of these structures and the models of the phosphonic acid complexes of the human ortholog provided an insight into the role of the additional amino group and the hydrophobic substituents of the ligands within the S1 active site region.

The clinical presentation of acute bacterial meningitis varies with age, sex and duration of illness

AIM

This Swedish study reviewed differences in clinical presentation and laboratory findings of acute bacterial meningitis in children aged one month to 17 years in Västerbotten County, Sweden.

METHODS

A register-based study was performed for the period 1986 to 2013 using the Västerbotten County Council's patient registration and laboratory records at the Department of Laboratory Medicine at Umeå University Hospital. The medical records were reviewed to extract data and confirm the diagnosis.

RESULTS

We found 103 cases of acute bacterial meningitis, and Haemophilus influenzae was the most common pathogen, causing 40.8% of all cases, followed by Streptococcus pneumoniae at 30.1% and Neisseria meningitidis at 9.7%. Significant differences in clinical presentation and laboratory findings were found. Younger children were more unwell than older ones and had more diffuse symptoms on admission. In addition, important sex-related differences were found that might explain the higher case fatality rates for boys than girls. For example, boys tended to have a higher disturbance in the blood-brain barrier, which is known to be a negative prognostic factor.

CONCLUSION

This study showed that clinical presentation for acute bacterial meningitis varied with age and sex and, to a lesser extent, on the duration of the illness.

Comparative proteomics of cerebrospinal fluid reveals a predictive model for differential diagnosis of pneumococcal, meningococcal, and enteroviral meningitis, and novel putative therapeutic targets

BACKGROUND

Meningitis is the inflammation of the meninges in response to infection or chemical agents. While aseptic meningitis, most frequently caused by enteroviruses, is usually benign with a self-limiting course, bacterial meningitis remains associated with high morbidity and mortality rates, despite advances in antimicrobial therapy and intensive care. Fast and accurate differential diagnosis is crucial for assertive choice of the appropriate therapeutic approach for each form of meningitis.

METHODS

We used 2D-PAGE and mass spectrometry to identify the cerebrospinal fluid proteome specifically related to the host response to pneumococcal, meningococcal, and enteroviral meningitis. The disease-specific proteome signatures were inspected by pathway analysis.

RESULTS

Unique cerebrospinal fluid proteome signatures were found to the three aetiological forms of meningitis investigated, and a qualitative predictive model with four protein markers was developed for the differential diagnosis of these diseases. Nevertheless, pathway analysis of the disease-specific proteomes unveiled that Kallikrein-kinin system may play a crucial role in the pathophysiological mechanisms leading to brain damage in bacterial meningitis. Proteins taking part in this cellular process are proposed as putative targets to novel adjunctive therapies.

CONCLUSIONS

Comparative proteomics of cerebrospinal fluid disclosed candidate biomarkers, which were combined in a qualitative and sequential predictive model with potential to improve the differential diagnosis of pneumococcal, meningococcal and enteroviral meningitis. Moreover, we present the first evidence of the possible implication of Kallikrein-kinin system in the pathophysiology of bacterial meningitis.

Predicting the optimum compositions of a parenteral nanoemulsion system loaded with azithromycin antibiotic utilizing the artificial neural network model

For the purpose of brain delivery via intravenous administration, the formulation of an azithromycin-loaded nanoemulsion system was optimized utilizing the artificial neural network (ANN) as a multivariate statistical technique.

Long-term effects from bacterial meningitis in childhood and adolescence on postural control

Bacterial meningitis in childhood is associated with cognitive deficiencies, sensorimotor impairments and motor dysfunction later in life. However, the long-term effects on postural control is largely unknown, e.g., whether meningitis subjects as adults fully can utilize visual information and adaptation to enhance stability. Thirty-six subjects (20 women, mean age 19.3 years) treated in childhood or adolescence for bacterial meningitis, and 25 controls (13 women, mean age 25.1 years) performed posturography with eyes open and closed under unperturbed and perturbed standing. The meningitis subjects were screened for subjective vertigo symptoms using a questionnaire, clinically tested with headshake and head thrust test, as well as their hearing was evaluated. Meningitis subjects were significantly more unstable than controls during unperturbed (p≤0.014) and perturbed standing, though while perturbed only with eyes open in anteroposterior direction (p = 0.034) whereas in lateral direction both with eyes open and closed (p<0.001). Meningitis subjects had poorer adaption ability to balance perturbations especially with eyes open, and they frequently reported symptoms of unsteadiness (88% of the subjects) and dizziness (81%), which was found significantly correlated to objectively decreased stability. Out of the 36 subjects only 3 had unilateral hearing impairment. Hence, survivors of childhood bacterial meningitis may suffer long-term disorders affecting postural control, and would greatly benefit if these common late effects became generally known so treatments can be developed and applied.

A pilot study of a wearable apnoea detection device

RATIONALE

Current techniques for monitoring patients for apnoea suffer from significant limitations. These include insufficient availability to meet diagnostic needs, cost, accuracy of results in the presence of artefacts and difficulty of use in unsupervised conditions.

OBJECTIVES

We created and clinically tested a novel miniature medical device that targets overcoming these limitations.

METHODS

We studied 20 healthy control participants and 10 patients who had been referred for sleep apnoea diagnosis. The performances of the new system and also of the Food and Drug Administration (FDA) approved SOMNO clinical system, conventionally used for sleep apnoea diagnosis were evaluated under the same conditions. Both systems were tested during a normal night of sleep in controls and patients. Their performances were quantified in terms of detection of apnoea and hypopnoea in individual 10 s epochs, which were compared with scoring of signals by a blinded clinician.

MAIN RESULTS

For spontaneous apnoeas during natural sleep and considering the clinician scorer as the gold standard, the new wearable apnoea detection device had 88.6% sensitivity and 99.6% specificity. In comparison the SOMNO system had 14.3% sensitivity and 99.3% specificity. The novel device had been specifically designed to detect apnoea, but if apnoea and hypopnoea during sleep were both considered in the assessment, the sensitivity and specificity were 77.1% and 99.7%, respectively, versus 54% and 98.5%, respectively, for the SOMNO.

CONCLUSIONS

The performance of the novel device compares very well to the scoring by an experienced clinician even in the presence of breathing artefacts, in this small pilot study. This can potentially make it a real solution for apnoea home monitoring.

Bacterial meningitis: a density-equalizing mapping analysis of the global research architecture

Bacterial meningitis is caused by a variety of pathogens and displays an important public health threat all over the world. Despite the necessity to develop customized public health-related research projects, a thorough study of global meningitis research is not present, so far. Therefore, the aim of this study was a combined density-equalizing and scientometric study. To evaluate the scientific efforts of bibliometric methods, density-equalizing algorithms and large-scale data analysis of the Web of Science were applied in the period between 1900 and 2007. From this, 7998 publications on bacterial meningitis have been found. With a number of 2698, most publications have been written by U.S. authors, followed by the UK (912), Germany (749) and France (620). This dominance can also be shown in the international cooperation. The specific citation analyses reveal that the nation with the highest average citation rate (citations per publications) was Norway (26.36), followed by Finland (24.16) and the U.S. (24.06). This study illustrates the architecture of global research on bacterial meningitis and points to the need for customized research programs with a focus on local public health issues in countries with a low development index, but high incidences, to target this global public health problem.

Hyperdense large artery sign in meningitis: A marker of ominous thrombogenic potential of pneumococcus?

Hyperdensity in the middle cerebral artery (MCA) or posterior cerebral artery (PCA) on non-contrast head CT, suggests the presence of a thrombus inside these vessels, often referred to as the “MCA sign” or “PCA sign” respectively. These two signs are classically associated with strokes secondary to cardiovascular etiologies and are only infrequently reported with other types of stroke. Whereas stroke is a recognized complication of pneumococcal meningitis hyperdense large vessel sign (in this case a combination of MCA and PCA) has not been previously reported. We report a case of rapidly progressive pneumococcal meningitis that presented as acute stroke involving large vessels in the vicinity of the circle of Willis in a patient with a history of non-Hodgkin lymphoma (NHL) in remission for 6 years. This patient had received a week of high dose steroids before admission. Head CT scan on admission showed the presence of hyperdense MCA and PCA signs. The patient rapidly deteriorated and a follow-up head CT revealed diffuse brain edema and increased density in the basal cisterns without evidence of sub arachnoid hemorrhage. Tc99m exametazime brain flow scan showed no intracerebral blood flow both supra and infratentorially. Steptococcus pneumoniae, NHL cells and high-dose steroid use can upregulate tissue factor synthesis and may have led to a hypercoagulable state via activation of the extrinsic pathway in the large intracerbral arteries.

An Acute Ibuprofen Overdose Masking a SevereStaphylococcus aureusMeningitis: A Case Report

Acute bacterial meningitis has a low incidence (3/100,000 in the United States) and yet high fatality rate (approximately 14–16%) and classically presents as a triad of fever, neck stiffness, and altered mental status. However, less than half of patients with meningitis present with this classic triad. We present the clinical course of a patient who initially presented to the emergency department after overdosing on ibuprofen for what he described as back pain secondary to mechanical injury. However, the patient's condition quickly deteriorated: he developed tachycardia, mental status changes, was intubated due to respiratory distress, and then suffered an 8-minute PEA arrest before return of spontaneous circulation was achieved. After the patient was stabilized, in addition to the nonsteroidal anti-inflammatory drug (NSAID) overdose Staphylococcus aureus meningitis, bacteremia, and pneumonia were diagnosed. We report this case to illustrate that the initial presentation of meningitis may be extremely unusual especially in the setting of NSAID overdose and the acutely decompensating patient. As the risk of adverse clinical outcomes increases with delays in appropriate antibiotic therapy, it is therefore crucial to recognize the many signs and symptoms of meningitis, typical and atypical, and quickly begin appropriate treatment.

An integrated approach to the ligand binding specificity of Neisseria meningitidis M1 alanine aminopeptidase by fluorogenic substrate profiling, inhibitory studies and molecular modeling

Neisseria meningitides is a gram-negative diplococcus bacterium and is the main causative agent of meningitis and other meningococcal diseases. Alanine aminopeptidase from N. meningitides (NmAPN) belongs to the family of metallo-exopeptidase enzymes, which catalyze the removal of amino acids from the N-terminus of peptides and proteins, and are found among all the kingdoms of life. NmAPN is suggested to be mostly responsible for proteolysis and nutrition delivery, similar to the orthologs from other bacteria. To explore the possibility of NmAPN being a potential drug target for inhibition and development of novel therapeutic agents, the specificity of the S1 and S1' binding sites was explored using an integrated approach. Initially, an extensive library consisting of almost 100 fluorogenic substrates derived from both natural and unnatural amino acids, were used to obtain a detailed substrate fingerprint of the S1 pocket of NmAPN. A broad substrate tolerance of NmAPN was revealed, with bulky basic and hydrophobic ligands being the most favored substrates. Additionally, the potency of a set of organophosphorus inhibitors of neutral aminopeptidases, amino acid and dipeptide analogs was determined. Inhibition constants in the nanomolar range, determined for phosphinic dipeptides, proves the positive increase in inhibition impact of the P1' ligand elongation. The results were further verified via molecular modeling and docking of canonical aminopeptidase phosphinic dipeptide inhibitors in the NmAPN active site. These studies present comprehensive characterization of interactions responsible for specific ligand binding. This knowledge provides invaluable insight into understanding of the enzyme and development of novel NmAPN inhibitors.

Infections of the nervous system

Glycemic control is an important aspect of patient care in the surgical Infections of the nervous system are among the most difficult infections in terms of the morbidity and mortality posed to patients, and thereby require urgent and accurate diagnosis. Although viral meningitides are more common, it is the bacterial meningitides that have the potential to cause a rapidly deteriorating condition that the physician should be familiar with. Viral encephalitis frequently accompanies viral meningitis, and can produce focal neurologic findings and cognitive difficulties that can mimic other neurologic disorders. Brain abscesses also have the potential to mimic and present like other neurologic disorders, and cause more focal deficits. Finally, other infectious diseases of the central nervous system, such as prion disease and cavernous sinus thrombosis, are explored in this review.

Clinical and laboratory features of Streptococcus salivarius meningitis: a case report and literature review

Streptococcus salivarius is a normal member of the human oral microbiome that is an uncommon cause of invasive infections. Meningitis is a rare but increasingly reported infection caused by S. salivarius. Despite the growing number of reported cases, a comprehensive review of the literature on S. salivarius meningitis is lacking. We sought to gain a better understanding of the clinical presentation, evaluation, management, and outcome of S. salivarius meningitis by analyzing previously reported cases. In addition to a single case reported here, 64 previously published cases of meningitis were identified for this review. The collected data confirm that most patients presented with classical signs and symptoms of bacterial meningitis with a predominance of neutrophils in the cerebrospinal fluid (CSF) and hypoglycorrhachia. The majority of cases followed iatrogenic or traumatic CSF contamination. Most cases were diagnosed by CSF culture within one day of symptom onset. There was no clear evidence of predisposing co-morbid conditions in patients with meningitis, although in most case reports, limited information was given on the medical history of each patient. Outcomes were generally favorable with antibiotic management. Clinicians should suspect S. salivarius meningitis in patients presenting acutely after medical or surgical procedures involving the meninges.

Headaches attributable to infectious diseases

Headache is the most common symptom that humans experience. While the vast majority of headaches are due to benign primary headache disorders, a small but important minority of headaches are due to secondary causes. Whereas significant emphasis is placed on educating physicians regarding prompt recognition of subarachnoid hemorrhage and headaches secondary to brain tumors, attention toward headaches secondary to infectious causes is often neglected. Unfortunately, a missed or delayed diagnosis of a headache secondary to meningitis, encephalitis, brain abscess, subdural empyema, or other infectious etiologies can lead to dire consequences for both the patient and physician. Accordingly, this article provides an overview of headaches attributed to systemic and intracranial infectious causes.

Long-term sequelae of childhood bacterial meningitis: an underappreciated problem

BACKGROUND

Numerous sequelae have been noted in survivors of bacterial meningitis; however, few studies document sequelae for several years following a childhood episode of bacterial meningitis. In addition, studies generally focus on the more commonly found sequelae. To review the known information and highlight this gap, this article presents a comprehensive literature review of the long-term (≥ 5 years of follow-up) sequelae of childhood bacterial meningitis.

METHODS

A systematic literature search was conducted between December 2009 and February 2010. English-language articles published between January 1970 and January 2010 were selected for screening. Articles were included if the subjects were between the ages of 1 month and <18 years at the time of diagnoses of meningitis.

RESULTS

A total of 1433 children who were survivors of childhood bacterial meningitis were evaluated for sequelae after the time of discharge. Of these children, 705 (49.2%) were reported to have 1 or more long-term sequelae. A majority of reported sequelae were behavioral and/or intellectual disorders (n 455, 45.0%). Hearing changes accounted for 6.7% (n 68) of sequelae and gross neurologic deficits accounted for 14.3% (n 145).

DISCUSSION

A majority of childhood bacterial meningitis survivors with long-term sequelae that are documented in the literature have academic and behavioral limitations. While neurologic deficits may resolve over time, subtle behavioral deficits may not be appreciated initially and may continue to affect survivors for many years. Further studies are needed to quantify the true societal and economic burden of long-term sequelae as well as fully understand the breadth of types of sequelae that survivors experience.

Therapeutic management of bacterial meningitis in children: a systematic review and comparison of published guidelines from a European perspective

Bacterial meningitis is an infectious disease emergency that can cause substantial morbidity and mortality. We compared the most recent international guidelines and recommendations on bacterial meningitis management in infants and children in developed countries, in terms of initial management approach, empirical antimicrobial therapy, timing, dosages, and duration of antimicrobial therapy, and possible adjunctive treatment with dexamethasone. Secondly, epidemiological data on bacterial resistance in several european countries were analyzed and discussed in relation to the therapies currently recommended for bacterial meningitis. The comparative analysis of the selected guidelines highlighted significant differences in the therapeutic management of bacterial meningitis. Differences among guidelines have important consequences for daily practice. An agreed protocol for early, evidence-based, and effective therapeutic management of bacterial meningitis is essential for the best outcome. further studies and expert consensus are required to establish the best management of bacterial meningitis in the european setting based on the most recent epidemiological data on resistance rates.

Rebound in the incidence of pneumococcal meningitis in northern France: effect of serotype replacement

AIM

To determine whether the recent emergence of nonvaccine pneumococcal serotypes has affected the incidence of pneumococcal meningitis in children a few years after the introduction of the heptavalent pneumococcal conjugate vaccine.

METHODS

We conducted a multicentre retrospective cohort study from 2005 to 2008 in all hospitals with paediatric units in northern France. It included all patients < 18 years of age who were admitted for laboratory-confirmed pneumococcal meningitis during the study period. Data were collected from medical files and laboratory records at each hospital and compared with the regional hospital discharge codes. We assessed global and age-specific incidence rates of pneumococcal meningitis from 2005 through 2008, compared them with those from the prevaccine era (2000-2002) and evaluated pneumococcal serotypes.

RESULTS

In all, 41 cases were found during the study period. The incidence rate of pneumococcal meningitis varied from 0.8/100,000 children < 18 years in 2005 to 1.8/100,000 children in 2008 (2.2-fold increase, p = 0.06); and from 1.8 to 11.9/100,000 children < 2 years (6.5-fold increase, p = 0.004). This increase was caused by nonvaccine pneumococcal serotypes.

CONCLUSION

The incidence of pneumococcal meningitis in infants has rebounded in northern France during the pneumococcal conjugate vaccine programme, with the emergence of nonvaccine pneumococcal serotypes.

Central nervous system infections as a cause of an altered mental status? What is the pathogen growing in your central nervous system?

There are several central nervous system (CNS) infections (meningitis, encephalitis, and brain abscess), any of which may present with an altered level of consciousness. Because CNS infections can have a devastating outcome, it is important to recognize the presence of a CNS infection and begin treatment as soon as possible because early appropriate therapy may, in some cases, limit morbidity and mortality.

Multiple therapeutic effects of adjunctive baicalin therapy in experimental bacterial meningitis

This study aimed to examine effects of adjunctive baicalin therapy to ampicillin for experimental bacterial meningitis in rabbits. After Escherichia Coli inoculation, mean leukocyte counts, concentrations of protein, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and lactate in cerebrospinal fluid (CSF), brain water content and mean arterial and intracranial pressures substantially increased in the meningitis group. Ampicillin alone for 5 h markedly exacerbated the enhanced leukocyte counts and protein concentration, and showed no significant effect on the elevated CSF TNF-alpha, IL-1 and lactate concentration, mean arterial and intracranial pressures, and brain water content. Baicalin (7-D-glucuronic acid-5,6-dihydroxyflavone, C(21)H(18)O(11)) completely counteracted ampicillin-induced exacerbation, and further alleviated the enhanced mean leukocyte counts and protein concentration when combined with ampicillin. Adjunctive baicalin also significantly ameliorated the elevated CSF TNF-alpha, IL-1 and lactate concentration, mean arterial and intracranial pressures, and brain water content. Baicillin, as an adjunctive treatment exerted multiple therapeutic effects in experimental bacterial meningitis.

Bacterial meningitis after traumatic thoracic fracture-dislocation: two case reports and review of the literature

Bacterial meningitis occurs rarely in the setting of traumatic spinal injury. Bacterial meningitis after spinal surgery for traumatic thoracic fracture-dislocation injuries has not been reported. We report on two cases of bacterial meningitis in two pediatric patients undergoing posterior segmental instrumentation with pedicle screws after thoracic fracture-dislocation injuries with associated traumatic dural laceration and complete spinal cord transection. Both patients were treated and recovered. Early recognition of bacterial meningitis after traumatic spinal injury enables appropriate and timely treatment to be instituted and can yield a favorable outcome.

Clinical decision rules for evaluating meningitis in children

PURPOSE OF REVIEW

Distinguishing between bacterial and aseptic meningitis in children is sometimes difficult. Guidelines recommend that patients with acute meningitis be systematically hospitalized and treated with antibiotics until the cerebrospinal fluid culture results are available. This strategy ensures rapid treatment for bacterial meningitis, but also involves unnecessary admissions and antibiotics for aseptic meningitis. Some authors have, therefore, proposed different combinations of predictors in clinical decision rules to distinguish as early as possible between bacterial and aseptic meningitis. To be useful, these rules must have near-100% sensitivity for bacterial meningitis, good specificity (to reduce unnecessary antibiotics and admissions), and easy bedside application.

RECENT FINDINGS

The present review examines the performance and level of validation of decision rules proposed after the Haemophilus influenzae vaccination entered widespread use. Most of these rules have been validated incompletely, if at all. Only one rule incorporates the best single validated predictive marker for distinguishing between bacterial and aseptic meningitis in children: serum procalcitonin level.

SUMMARY

Two rules are highly promising, meeting the three major conditions after a retrospective validation process in large samples. These rules can be applied cautiously to patients with the same inclusion and exclusion criteria as those in the derivation sets, while awaiting prospective multicenter validation studies.

Identifying low-risk patients for bacterial meningitis in adult patients with acute meningitis

OBJECTIVE

To derive and validate a clinical prediction model with high sensitivity for differentiating aseptic meningitis (AM) patients from bacterial meningitis (BM) patients.

METHODS

We developed the model using the derivation cohort in a community rural hospital in Okinawa and assessed its performance using the validation cohort in a metropolitan urban hospital in Tokyo. There were 66 (39.5%) and 5 (17.9%) adult patients with BM among the derivation (n=167) and the validation cohort (n=28), respectively. Recursive partitioning analysis was used to determine the important classification variables and to develop a sensitive model to safely exclude BM.

RESULTS

The model produced high- and low-risk groups based on the following: 1) Gram stain, 2) CSF neutrophil percent < or =15%, 3) CSF neutrophil count < or =150 cells/mm(3), and, 4) mental status change. Among the derivation cohort, there were 65 patients with BM in the high-risk group (n=76), while only one patient with BM was noted (sensitivity, 99%) in the low-risk group (n=91). Among the validation cohort, there were 5 patients with BM in the high-risk group (n=7), while no patient was classified with BM (sensitivity, 100%) in the low-risk group (n=21).

CONCLUSION

This simple and sensitive model might be useful to safely identify low-risk patients for BM who would not require antibiotic treatment.