Clinical presentation and prognostic factors of Streptococcus pneumoniae meningitis according to the focus of infection

Global Case Fatality of Bacterial Meningitis During an 80-Year Period: A Systematic Review and Meta-Analysis

Importance

The impact of vaccination, antibiotics, and anti-inflammatory treatment on pathogen distribution and outcome of bacterial meningitis over the past century is uncertain.

Objective

To describe worldwide pathogen distribution and case fatality ratios of community-acquired bacterial meningitis.

Data Sources

Google Scholar and MEDLINE were searched in January 2022 using the search terms bacterial meningitis and mortality.

Study Selection

Included studies reported at least 10 patients with bacterial meningitis and survival status. Studies that selected participants by a specific risk factor, had a mean observation period before 1940, or had more than 10% of patients with health care-associated meningitis, tuberculous meningitis, or missing outcome were excluded.

Data Extraction and Synthesis

Data were extracted by 1 author and verified by a second author. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Random-effects models stratified by age (ie, neonates, children, adults), Human Development Index (ie, low-income or high-income countries), and decade and meta-regression using the study period's year as an estimator variable were used.

Main Outcome and Measure

Case fatality ratios of bacterial meningitis.

Results

This review included 371 studies performed in 108 countries from January 1, 1935, to December 31, 2019, describing 157 656 episodes. Of the 33 295 episodes for which the patients' sex was reported, 13 452 (40%) occurred in females. Causative pathogens were reported in 104 598 episodes with Neisseria meningitidis in 26 344 (25%) episodes, Streptococcus pneumoniae in 26 035 (25%) episodes, Haemophilus influenzae in 22 722 (22%), other bacteria in 19 161 (18%) episodes, and unidentified pathogen in 10 336 (10%) episodes. The overall case fatality ratio was 18% (95% CI, 16%-19%), decreasing from 32% (95% CI, 24%-40%) before 1961 to 15% (95% CI, 12%-19%) after 2010. It was highest in meningitis caused by Listeria monocytogenes at 27% (95% CI, 24%-31%) and pneumococci at 24% (95% CI, 22%-26%), compared with meningitis caused by meningococci at 9% (95% CI, 8%-10%) or H influenzae at 11% (95% CI, 10%-13%). Meta-regression showed decreasing case fatality ratios overall and stratified by S pneumoniae, Escherichia coli, or Streptococcus agalactiae (P < .001).

Conclusions and Relevance

In this meta-analysis with meta-regression, declining case fatality ratios of community-acquired bacterial meningitis throughout the last century were observed, but a high burden of disease remained.

How common is otogenic meningitis? A retrospective study in southern Sweden over 18 years

BACKGROUND

Bacterial meningitis is a rare, but life-threatening disease, which sometimes occurs as a complication to acute otitis media (AOM). The proportion of meningitis cases originating from AOM is not clear.

PURPOSE

The aim of this study was to investigate the proportion of meningitis cases caused by AOM, to compare risk factors, bacteriology and outcome between otogenic and non-otogenic meningitis, and to analyse the incidence of bacterial meningitis after the introduction of conjugate pneumococcal vaccines (PCV).

METHODS

The medical charts of all patients admitted to hospitals in southern Sweden with bacterial meningitis between 2000 and 2017 were retrieved. Based on otoscopy and/or imaging, the proportion of otogenic meningitis cases was calculated, as were annual incidences.

RESULTS

A total of 216 patients were identified, 25 of whom died. The proportion of otogenic meningitis was 31% but varied from 6% among teenagers to 40% among adults. Before PCV, 23% of all meningitis cases were children < 2 years, compared to 1% post-PCV. The average incidence in the adult population, on the other hand, increased post-PCV, though there were large annual variations. S. pneumoniae was the most commonly identified pathogen in everyone but teenagers, in whom N. meningitidis was predominant.

CONCLUSION

AOM is an important cause of meningitis in children and adults. Though bacterial meningitis almost disappeared in children < 2 years after the introduction of PCV, the incidence of pneumococcal meningitis in adults seems to have increased.

Clinical Picture and Risk Factors for Poor Outcome in Streptococcus pneumoniae Meningitis of Childhood on Three Continents

BACKGROUND

Streptococcus pneumoniae meningitis (SpM) remains a major health burden worldwide, particularly in low- and middle-income countries. Identifying the patients at highest risk for mortality and disabling sequelae may reveal potentially avoidable predisposing factors and identify patients most in need of intensive care. We searched for factors that do not require laboratory facilities.

METHODS

This study was a secondary analysis of prospectively collected data from 5 clinical trials of childhood bacterial meningitis on 3 continents between 1984 and 2017. SpM cases were analyzed by study site and predictors for poor outcome (death or severe sequelae) were identified from the whole series, Latin America and Angola.

RESULTS

Among a total of 1575 children (age range: 2 months to 15 years), 505 cases were due to pneumococci. Compared to other etiologies, SpM doubled the death rate (33% vs. 17%) and tripled poor outcome (15% vs. 6%). In SpM, Glasgow Coma Score <13 [odds ratio (OR): 4.73] and previous antibiotics in Angola (OR: 1.70) were independent predictors for death. Predictors for poor outcome were age <1 year (OR: 2.41) and Glasgow Coma Score <13 (OR: 6.39) in the whole series, seizures in Latin America (OR: 3.98) and previous antibiotics in Angola (OR: 1.91). Angolan children had a 17-fold increased risk for poor outcome when compared with Finnish children ( P = 0.011).

CONCLUSIONS

Our study proved the severity of SpM when compared with other etiologies. The outcome was especially poor in Angola. Most patients at risk for poor outcome are easily identified by clinical factors on admission.

Pneumonia in childhood bacterial meningitis-Experience from three continents

INTRODUCTION

Although concomitant pneumonia is sometimes diagnosed in childhood bacterial meningitis, its role in the illness course and prognosis is not known. We examined these associations using prospectively collected data from Finland, Latin America and Angola.

METHODS

This was a secondary descriptive analysis of prospectively collected data (clinical and laboratory findings at admission, during hospitalisation and outcome) from five clinical bacterial meningitis trials. We included children aged 2 months to 15 years from sites with confirmed bacterial meningitis and potential concomitant pneumonia (diagnosed clinically with or without a chest radiograph).

RESULTS

Pneumonia was not observed in the 341 children included in Finland. Pneumonia was observed in 8% (51/606) of children in Latin America and in 46% (377/819) in Angola (p < 0.0001). In multivariate analyses, predisposing factors for pneumonia in Latin America were age <1 year, seizures and severe anaemia; the corresponding factors for Angola were preadmission duration of illness >3 days and non-meningococcal meningitis. Concomitant pneumonia increased the severity of the disease and disabling sequelae.

CONCLUSION

Bacterial meningitis with pneumonia is a major, previously undescribed entity of severe bacterial meningitis, especially in Angola.

Streptococcus bovis infection of the central nervous system in adults: Report of 4 cases and literature review

OBJECTIVES

To describe the clinical features, history and association with intestinal disease in central nervous system (CNS) S. bovis infections.

METHODS

Four cases of S. bovis CNS infections from our institution are presented. Additionally a systematic literature review of articles published between 1975 and 2021 in PubMed/MEDLINE was conducted.

RESULTS

52 studies with 65 cases were found; five were excluded because of incomplete data. In total 64 cases were analyzed including our four cases: 55 with meningitis and 9 with intracranial focal infections. Both infections were frequently associated with underlying conditions (70.3%) such as immunosuppression (32.8%) or cancer (10.9%). In 23 cases a biotype was identified, with biotype II being the most frequent (69.6%) and S. pasteurianus the most common within this subgroup. Intestinal diseases were found in 60.9% of cases, most commonly neoplasms (41.0%) and Strongyloides infestation (30.8%). Overall mortality was 17.1%, with a higher rate in focal infection (44.4% vs 12.7%; p=0.001).

CONCLUSIONS

CNS infections due to S. bovis are infrequent and the most common clinical form is meningitis. Compared with focal infections, meningitis had a more acute course, was less associated with endocarditis and had a lower mortality. Immunosuppression and intestinal disease were frequent in both infections.

Risk factors and pathogen characteristics associated with unfavorable outcomes among adults with pneumococcal meningitis in Japan, 2006 to 2016

PURPOSE

In this study, we aimed to clarify the risk factors associated with unfavorable outcomes in adults with pneumococcal meningitis (PnM).

METHODS

Surveillance was conducted between 2006 and 2016. Adults with PnM (n = 268) were followed up for outcomes within 28 days after admission using the Glasgow Outcome Scale (GOS). After classifying the patients into the unfavorable (GOS1-4) and favorable (GOS5) outcome groups, i) the underlying diseases, ii) biomarkers at admission, and iii) serotype, genotype, and antimicrobial susceptibility for all isolates were compared between both groups.

RESULTS

Overall, 58.6% of patients with PnM survived,15.3% died, and 26.1% had sequelae. The number of living days in the GOS1 group was highly heterogeneous. Motor dysfunction, disturbance of consciousness, and hearing loss were the commonest sequelae. Of the underlying diseases identified in 68.9% of the PnM patients, liver and kidney diseases were significantly associated with unfavorable outcomes. Of the biomarkers, creatinine and blood urea nitrogen, followed by platelet and C-reactive protein had the most significant associations with unfavorable outcomes. There was a significant difference in the high protein concentrations in the cerebrospinal fluid between the groups. Serotypes 23F, 6C, 4, 23A, 22F, 10A, and 12F were associated with unfavorable outcomes. These serotypes were not penicillin-resistant isolates possessing three abnormal pbp genes (pbp1a, 2x, and 2b), except for 23F. The expected coverage rate of the pneumococcal conjugate vaccine (PCV) was 50.7% for PCV15 and 72.4% for PCV20.

CONCLUSIONS

In the introduction of PCV for adults, the risk factors for underlying diseases should be prioritized over age, and serotypes with unfavorable outcomes should be considered.

Bacteria hijack a meningeal neuroimmune axis to facilitate brain invasion

The meninges are densely innervated by nociceptive sensory neurons that mediate pain and headache1,2. Bacterial meningitis causes life-threatening infections of the meninges and central nervous system, affecting more than 2.5 million people a year3-5. How pain and neuroimmune interactions impact meningeal antibacterial host defences are unclear. Here we show that Nav1.8+ nociceptors signal to immune cells in the meninges through the neuropeptide calcitonin gene-related peptide (CGRP) during infection. This neuroimmune axis inhibits host defences and exacerbates bacterial meningitis. Nociceptor neuron ablation reduced meningeal and brain invasion by two bacterial pathogens: Streptococcus pneumoniae and Streptococcus agalactiae. S. pneumoniae activated nociceptors through its pore-forming toxin pneumolysin to release CGRP from nerve terminals. CGRP acted through receptor activity modifying protein 1 (RAMP1) on meningeal macrophages to polarize their transcriptional responses, suppressing macrophage chemokine expression, neutrophil recruitment and dural antimicrobial defences. Macrophage-specific RAMP1 deficiency or pharmacological blockade of RAMP1 enhanced immune responses and bacterial clearance in the meninges and brain. Therefore, bacteria hijack CGRP-RAMP1 signalling in meningeal macrophages to facilitate brain invasion. Targeting this neuroimmune axis in the meninges can enhance host defences and potentially produce treatments for bacterial meningitis.

Clinical Characteristics, Antimicrobial Resistance, and Outcomes of Patients with Invasive Pneumococcal Disease in Ningxia Hui Autonomous Region, China, 2013-2021

Objectives

This study aimed to analyze the clinical features, antibiotic susceptibility profiles, and outcomes of patients with invasive pneumococcal disease (IPD) at a hospital in Ningxia Hui Autonomous Region, to provide the basis for improving the clinical treatment effect.

Methods

Patients with IPD were retrospectively collected from 2013 to 2021. Clinical manifestations, laboratory tests, antimicrobial susceptibility, antibiotic treatment, and outcomes of the disease were analyzed.

Results

In this study, we identified 127 IPD cases, of whom 49 (38.6%) had meningitis and 78 (61.4%) had bacteremia. The median ages of pediatric cases and adult cases were 2 years (IQR: 0-5) and 52.5 years (IQR: 35-62), respectively. There were 27 and 45 males in the pediatric and adult groups, and no significant gender difference in the different age groups (p = 0.584) was found. Of 75 cases with underlying diseases, pneumonia (11%), malignancy (11%), hypertension (9.4%), and hepatic cirrhosis (7.9%) were the most common. The incidence of underlying diseases was even higher in the adult group (67.1%) than in the pediatric group (47.1%) (p = 0.028). The frequency of fever, cough, and seizures was significantly higher in the pediatric group than in the adult group, with p-values of 0.004, 0.004, and 0.001, respectively. The percentage of neutrophils in the blood was significantly higher in the adult cases than in the pediatric cases (p  <  0.001). Furthermore, there was a significantly higher WBC count (p  <  0.001), percentage of neutrophils (p = 0.012), and protein level (p = 0.019) in the CSF samples in the adult patients compared to pediatric patients. The susceptibility rates of S. pneumoniae isolates to vancomycin, linezolid, and levofloxacin were 100%. The susceptibility rates of penicillin were 98.7% and 34.1% in bacteremia and meningitis patients, respectively. Most isolates were resistant to erythromycin, clindamycin, tetracycline, and azithromycin. The most common antibiotic treatment was β-lactams. Seven (5.5%) patients died during hospitalization, and 38 (29.9%) patients' health deteriorated.

Conclusion

These results may provide a reference basis for the diagnosis and empiric treatment of IPD in the region.

Respiratory immune status and microbiome in recovered COVID-19 patients revealed by metatranscriptomic analyses

Coronavirus disease 2019 (COVID-19) is currently a severe threat to global public health, and the immune response to COVID-19 infection has been widely investigated. However, the immune status and microecological changes in the respiratory systems of patients with COVID-19 after recovery have rarely been considered. We selected 72 patients with severe COVID-19 infection, 57 recovered from COVID-19 infection, and 65 with non-COVID-19 pneumonia, for metatranscriptomic sequencing and bioinformatics analysis. Accordingly, the differentially expressed genes between the infected and other groups were enriched in the chemokine signaling pathway, NOD-like receptor signaling pathway, phagosome, TNF signaling pathway, NF-kappa B signaling pathway, Toll-like receptor signaling pathway, and C-type lectin receptor signaling pathway. We speculate that IL17RD, CD74, and TNFSF15 may serve as disease biomarkers in COVID-19. Additionally, principal coordinate analysis revealed significant differences between groups. In particular, frequent co-infections with the genera Streptococcus, Veillonella, Gemella, and Neisseria, among others, were found in COVID-19 patients. Moreover, the random forest prediction model with differential genes showed a mean area under the curve (AUC) of 0.77, and KCNK12, IL17RD, LOC100507412, PTPRT, MYO15A, MPDZ, FLRT2, SPEG, SERPINB3, and KNDC1 were identified as the most important genes distinguishing the infected group from the recovered group. Agrobacterium tumefaciens, Klebsiella michiganensis, Acinetobacter pittii, Bacillus sp. FJAT.14266, Brevundimonas naejangsanensis, Pseudopropionibacterium propionicum, Priestia megaterium, Dialister pneumosintes, Veillonella rodentium, and Pseudomonas protegens were selected as candidate microbial markers for monitoring the recovery of COVID patients. These results will facilitate the diagnosis, treatment, and prognosis of COVID patients recovering from severe illness.

Healthy adults with Streptococcus pneumoniae meningitis and Streptococcus pneumoniae subdural abscess: two case reports and a literature review

We present the cases of two otherwise healthy adults, one with meningitis and another with a subdural abscess, with both conditions attributable to Streptococcus pneumoniae. A 31-year-old man was admitted with a 3-day history of fever, headache, and vomiting. Physical examination revealed intermittent confusion, irritability, and neck stiffness. Cerebrospinal fluid (CSF) culture was positive for S. pneumoniae. Contrast-enhanced magnetic resonance imaging (C-MRI) revealed multiple small lesions on the bilateral frontal lobes. Intravenous ceftriaxone and vancomycin were administered, followed by intravenous moxifloxacin. His symptoms resolved within 3 months. Additionally, a 66-year-old man was admitted for acute fever with confusion, abnormal behavior, and a recent history of acute respiratory infection. Physical examination revealed confusion, neck stiffness, and a positive right Babinski sign. CSF metagenomic analysis detected S. pneumoniae. C-MRI disclosed left occipitotemporal meningoencephalitis with subdural abscesses. Intravenous ceftriaxone was administered for 3 weeks. His condition gradually improved, with resorbed lesions detected on repeat MRI. This study expanded the clinical and imaging spectra of S. pneumoniae meningitis. In healthy adults, S. pneumoniae can invade the brain, but subdural abscess is a rare neuroimaging manifestation. Early diagnosis of S. pneumoniae meningitis by high-throughput sequencing and flexible treatment strategies are necessary for satisfactory outcomes.

Spatial and temporal variation of routine parameters: pitfalls in the cerebrospinal fluid analysis in central nervous system infections

The cerebrospinal fluid (CSF) space is convoluted. CSF flow oscillates with a net flow from the ventricles towards the cerebral and spinal subarachnoid space. This flow is influenced by heartbeats, breath, head or body movements as well as the activity of the ciliated epithelium of the plexus and ventricular ependyma. The shape of the CSF space and the CSF flow preclude rapid equilibration of cells, proteins and smaller compounds between the different parts of the compartment. In this review including reinterpretation of previously published data we illustrate, how anatomical and (patho)physiological conditions can influence routine CSF analysis. Equilibration of the components of the CSF depends on the size of the molecule or particle, e.g., lactate is distributed in the CSF more homogeneously than proteins or cells. The concentrations of blood-derived compounds usually increase from the ventricles to the lumbar CSF space, whereas the concentrations of brain-derived compounds usually decrease. Under special conditions, in particular when distribution is impaired, the rostro-caudal gradient of blood-derived compounds can be reversed. In the last century, several researchers attempted to define typical CSF findings for the diagnosis of several inflammatory diseases based on routine parameters. Because of the high spatial and temporal variations, findings considered typical of certain CNS diseases often are absent in parts of or even in the entire CSF compartment. In CNS infections, identification of the pathogen by culture, antigen detection or molecular methods is essential for diagnosis.

Differential Pneumococcal Growth Features in Severe Invasive Disease Manifestations

The nasopharyngeal commensal Streptococcus pneumoniae can become invasive and cause metastatic infection. This requires the pneumococcus to have the ability to adapt, grow, and reside in diverse host environments. Therefore, we studied whether the likelihood of severe disease manifestations was related to pneumococcal growth kinetics. For 383 S. pneumoniae blood isolates and 25 experimental mutants, we observed highly reproducible growth curves in nutrient-rich medium. The derived growth features were lag time, maximum growth rate, maximum density, and stationary-phase time before lysis. First, the pathogenicity of each growth feature was probed by comparing isolates from patients with and without marked preexisting comorbidity. Then, growth features were related to the propensity of causing severe manifestations of invasive pneumococcal disease (IPD). A high maximum bacterial density was the most pronounced pathogenic growth feature, which was also an independent predictor of 30-day mortality (P = 0.03). Serotypes with an epidemiologically higher propensity for causing meningitis displayed a relatively high maximum density (P < 0.005) and a short stationary phase (P < 0.005). Correspondingly, isolates from patients diagnosed with meningitis showed an especially high maximum density and short stationary phase compared to isolates from the same serotype that had caused uncomplicated bacteremic pneumonia. In contrast, empyema-associated strains were characterized by a relatively long lag phase (P < 0.0005), and slower growth (P < 0.005). The course and dissemination of IPD may partly be attributable to the pneumococcal growth features involved. If confirmed, we should tailor the prevention and treatment strategies for the different infection sites that can complicate IPD.

IMPORTANCEStreptococcus pneumoniae is a leading infectious cause of deaths worldwide. To understand the course and outcome of pneumococcal infection, most research has focused on the host and its response to contain bacterial growth. However, bacterial epidemiology suggest that certain pneumococcal serotypes are particularly prone to causing complicated infections. Therefore, we took the bacterial point of view, simply examining in vitro growth features for hundreds of pneumococcal blood isolates. Their growth curves were very reproducible. Certain poles of pneumococcal growth features were indeed associated with specific clinical manifestations like meningitis or pleural empyema. This indicates that bacterial growth style potentially affects the progression of infection. Further research on bacterial growth and adaptation to different host environments may therefore provide key insight into pathogenesis of complicated invasive disease. Such knowledge could lead to more tailored vaccine targets or therapeutic approaches to reduce the million deaths that are caused by pneumococcal disease every year.

Evaluation of Rat Brain Morphology Following the Induction of Acute Meningitis Treated with Ceftriaxone

The soft and delicate tissue of the brain, which is the center of our coordination, is protected by its surrounding layers. The disruption of these layers results in complicated situations and serious health problems. The brain has three protective layers of bone or skull tissue, the blood tissue layer, and finally the meningeal layer. The layer of blood tissue contains the blood vessels that are located between the skull and the meningeal membranes. If germs or foreign matter enter the fluid through the blood vessels under any circumstances and cause infection, the bones that protect the meninges will break and cause tissue damage. The present study aimed to assess the histological and immunohistochemical characteristics of the brain of rats that underwent induced acute purulent pneumococcal meningitis after antibiotic therapy with Ceftriaxone. A number of 20 white adult male Wistar rats were assigned to three groups. The first group (n=5) regarded as the control were injected with a saline solution into the subarachnoid space in an equivalent amount. The second and third groups of rats (n=5 and 10, respectively) were infected with acute purulent meningitis by the injection of 10 μl of Streptococcus pneumoniae (S. pneumonia) suspension into the subarachnoid space of the brain using a 23-G needle. The various areas of the brains of rats after meningitis induced by S. pneumoniae were examined after the treatment with Ceftriaxone. The S. pneumoniae culture was injected into the subarachnoid space in the area of the rhomboid fossa. Treatment started 18 h after the injection. On day 10, a repeated puncture was performed with the analysis of cerebrospinal fluid in order to confirm the absence of meningitis; thereafter, the animals were taken out of the experiment. No signs of meningitis were found on histological examination. Mild perivascular and pericellular focal edema were revealed with signs of overload of the lymphatic system in the brain and focal ischemic changes in neurons. The investigation of expression with caspase-3 revealed a positive reaction of individual neurons. A positive reaction with antibodies to NeuN and Doublecortin was detected in most neurons; moreover, Glial fibrillary acidic protein (GFAP)-positive astrocytes and their processes were visualized in all layers of the brain substance. The reaction with neuron-specific enolase (NSE), microtubule-associated protein 2 (MAP-2), CD 31, and CD 34 was negative. Typical structure and pictures pointed to an intact brain and purulent meningitis in the first and second groups. The microscopic image and the changes revealed during immunohistochemistry by dual corticosteroid antibodies and neuronal nuclear protein were characterized by predominantly cytoplasmic and perinuclear reactions, respectively. Some neurons are positive for caspase-3 and are related to changes in the characteristic of premature aging.

Bacterial Meningitis in Children: Neurological Complications, Associated Risk Factors, and Prevention

Bacterial meningitis is a devastating infection, with a case fatality rate of up to 30% and 50% of survivors developing neurological complications. These include short-term complications such as focal neurological deficit and subdural effusion, and long-term complications such as hearing loss, seizures, cognitive impairment and hydrocephalus. Complications develop due to bacterial toxin release and the host immune response, which lead to neuronal damage. Factors associated with increased risk of developing neurological complications include young age, delayed presentation and Streptococcus pneumoniae as an etiologic agent. Vaccination is the primary method of preventing bacterial meningitis and therefore its complications. There are three vaccine preventable causes: Haemophilus influenzae type b (Hib), S. pneumoniae, and Neisseria meningitidis. Starting antibiotics without delay is also critical to reduce the risk of neurological complications. Additionally, early adjuvant corticosteroid use in Hib meningitis reduces the risk of hearing loss and severe neurological complications.

Complications in Pediatric Acute Mastoiditis: HCUP KID Analysis

OBJECTIVE

A small proportion of children with otitis media develop acute mastoiditis, which has the potential to spread intracranially and result in significant morbidity and mortality. The aim of this study was to evaluate the incidence and management of complications related to pediatric acute mastoiditis using a national database.

STUDY DESIGN

Retrospective review of 2016 Kids' Inpatient Database, part of the Healthcare Cost and Utilization Project.

SETTING

Academic, community, general, and pediatric specialty hospitals in the United States.

METHODS

International Classification of Diseases, Tenth Revision, Clinical Modification code H70.XXX was used to retrieve records for children admitted with a diagnosis of mastoiditis. Data included patient demographics, intracranial infections, procedures (middle ear drainage, mastoidectomy, and intracranial drainage), length of stay (LOS), and total charges.

RESULTS

In total, 2061 children aged ≤21 years were identified with a diagnosis of acute mastoiditis. Complications included subperiosteal abscess (6.90%), intracranial thrombophlebitis/thrombosis (5.30%), intracranial abscess (3.90%), otitic hydrocephalus (1.20%), encephalitis (0.90%), subperiosteal abscess with intracranial complication (0.60%), petrositis (0.60%), and meningitis (0.30%). Children with intracranial abscesses were more likely (P < .001) to undergo myringotomy ± ventilation tube insertion (63.7%), mastoidectomy (53.8%), mastoidectomy with ventilation tube or myringotomy (42.5%), intracranial drainage procedure (36.3%), or all 3 key procedures (15.0%). Children with any type of intracranial complication had a significantly longer LOS (P < .001) and higher total charges (P < .001). Both a diagnosis of bacterial meningitis and undergoing an intracranial drainage procedure (P < .001) contributed significantly to LOS and total charges.

CONCLUSION

Patients with intracranial complications are more likely to undergo surgical procedures; however, there is still wide variability in practice patterns, illustrating that controversies in the management of otitis media complications persist.

Overview of Brain-to-Gut Axis Exposed to Chronic CNS Bacterial Infection(s) and a Predictive Urinary Metabolic Profile of a Brain Infected by Mycobacterium tuberculosis

A new paradigm in neuroscience has recently emerged - the brain-gut axis (BGA). The contemporary focus in this paradigm has been gut → brain ("bottom-up"), in which the gut-microbiome, and its perturbations, affects one's psychological state-of-mind and behavior, and is pivotal in neurodegenerative disorders. The emerging brain → gut ("top-down") concept, the subject of this review, proposes that dysfunctional brain health can alter the gut-microbiome. Feedback of this alternative bidirectional highway subsequently aggravates the neurological pathology. This paradigm shift, however, focuses upon non-communicable neurological diseases (progressive neuroinflammation). What of infectious diseases, in which pathogenic bacteria penetrate the blood-brain barrier and interact with the brain, and what is this effect on the BGA in bacterial infection(s) that cause chronic neuroinflammation? Persistent immune activity in the CNS due to chronic neuroinflammation can lead to irreversible neurodegeneration and neuronal death. The properties of cerebrospinal fluid (CSF), such as immunological markers, are used to diagnose brain disorders. But what of metabolic markers for such purposes? If a BGA exists, then chronic CNS bacterial infection(s) should theoretically be reflected in the urine. The premise here is that chronic CNS bacterial infection(s) will affect the gut-microbiome and that perturbed metabolism in both the CNS and gut will release metabolites into the blood that are filtered (kidneys) and excreted in the urine. Here we assess the literature on the effects of chronic neuroinflammatory diseases on the gut-microbiome caused by bacterial infection(s) of the CNS, in the context of information attained via metabolomics-based studies of urine. Furthermore, we take a severe chronic neuroinflammatory infectious disease - tuberculous meningitis (TBM), caused by Mycobacterium tuberculosis, and examine three previously validated CSF immunological biomarkers - vascular endothelial growth factor, interferon-gamma and myeloperoxidase - in terms of the expected changes in normal brain metabolism. We then model the downstream metabolic effects expected, predicting pivotal altered metabolic pathways that would be reflected in the urinary profiles of TBM subjects. Our cascading metabolic model should be adjustable to account for other types of CNS bacterial infection(s) associated with chronic neuroinflammation, typically prevalent, and difficult to distinguish from TBM, in the resource-constrained settings of poor communities.

Adult Otogenic Meningitis in the Pneumococcal Conjugated Vaccines Era

Introduction   Streptococcus pneumoniae is a major pathogen of otogenic meningitis (OgM), the most commonly reported intra-cranial complication of otitis media (OM). Objectives  To study the changes in adult OgM patients in the pneumococcal conjugated vaccines (PCVs) era. Methods  Retrospective cohort of adults presenting with concurrent OM and meningitis in a secondary medical care center between 2005 and 2015. Data collected included demographics, OM-related symptoms, cerebrospinal fluid (CSF) and ear culture results, pre- and during hospitalization antibiotic treatment, imaging findings, and complications. We compared the pre-PCV years (2005-2009) with the post-PCV years (2010-2015). Outcomes were 1) incidence of all-cause adult OgM from the total meningitis cases; 2) impact of PCVs on the clinical presentation of OgM and bacteriology. Results  Otogenic meningitis was diagnosed in 26 out of 45 (58%) cases of all-cause meningitis admissions. Of those, 10 (38%) were male, with a mean age of 62.4 years old. Ear-related signs and symptoms were documented in 70% of the patients, and OgM was diagnosed following imaging studies in 6 out of 26 (23%) patients. All of the patients received intravenous antibiotic therapy, and 7 (27%) patients required surgical interventions: 6 required myringotomy and 1 required mastoidectomy. There were 12 (46%) patients in the pre-PCV years and 14 (56%) in the post-PCV years. The positive pneumococcal CSF and ear culture rates remained high and unchanged (∼ 75%). There were no significant changes in the clinical presentation or mortality rates. Conclusion  Micro-otoscopy should be included in the routine work-up of any suspected adult meningitis, because OgM is underdiagnosed. Unlike their impact on pediatric otitis media, PCVs did not change the epidemiology and bacteriology of OgM.

S1 guidelines "lumbar puncture and cerebrospinal fluid analysis" (abridged and translated version)

Introduction

Cerebrospinal fluid (CSF) analysis is important for detecting inflammation of the nervous system and the meninges, bleeding in the area of the subarachnoid space that may not be visualized by imaging, and the spread of malignant diseases to the CSF space. In the diagnosis and differential diagnosis of neurodegenerative diseases, the importance of CSF analysis is increasing. Measuring the opening pressure of CSF in idiopathic intracranial hypertension and at spinal tap in normal pressure hydrocephalus constitute diagnostic examination procedures with therapeutic benefits.Recommendations (most important 3-5 recommendations on a glimpse): The indications and contraindications must be checked before lumbar puncture (LP) is performed, and sampling CSF requires the consent of the patient.Puncture with an atraumatic needle is associated with a lower incidence of postpuncture discomfort. The frequency of postpuncture syndrome correlates inversely with age and body mass index, and it is more common in women and patients with a history of headache. The sharp needle is preferably used in older or obese patients, also in punctures expected to be difficult.In order to avoid repeating LP, a sufficient quantity of CSF (at least 10 ml) should be collected. The CSF sample and the serum sample taken at the same time should be sent to a specialized laboratory immediately so that the emergency and basic CSF analysis program can be carried out within 2 h.The indication for LP in anticoagulant therapy should always be decided on an individual basis. The risk of interrupting anticoagulant therapy must be weighed against the increased bleeding risk of LP with anticoagulant therapy.As a quality assurance measure in CSF analysis, it is recommended that all cytological, clinical-chemical, and microbiological findings are combined in an integrated summary report and evaluated by an expert in CSF analysis.

Conclusions

In view of the importance and developments in CSF analysis, the S1 guideline "Lumbar puncture and cerebrospinal fluid analysis" was recently prepared by the German Society for CSF analysis and clinical neurochemistry (DGLN) and published in German in accordance with the guidelines of the AWMF (https://www.awmf.org). /uploads/tx_szleitlinien/030-141l_S1_Lumbalpunktion_und_Liquordiagnostik_2019-08.pdf). The present article is an abridged translation of the above cited guideline. The guideline has been jointly edited by the DGLN and DGN.

Community-acquired pneumonia in patients with bacterial meningitis: a prospective nationwide cohort study

OBJECTIVE

Pneumonia is considered a focus of infection in patients presenting with community-acquired bacterial meningitis but the impact on disease course is unclear. The aim was to study presenting characteristics, clinical course and outcome of meningitis patients with co-existing pneumonia on admission.

METHODS

We evaluated adult patients with community-acquired bacterial meningitis with pneumonia on admission in a nationwide, prospective cohort performed from March 2006 to June 2017. We performed logistic regression analysis to identify clinical characteristics predictive of pneumonia on admission, and to quantify the effect of pneumonia on outcome.

RESULTS

Pneumonia was diagnosed on admission in 315 of 1852 (17%) bacterial meningitis episodes and confirmed by chest X-ray in 256 of 308 (83%) episodes. Streptococcus pneumoniae was the causative organism in 256 of 315 episodes (81%). Pneumonia on admission was associated with advanced age (OR 1.03 per year increase, 95% CI 1.02-1.04, p < 0.001), alcoholism (OR 1.96, 95% CI 1.23-3.14, p 0.004), cancer (OR 1.54, 95% CI 1.12-2.13, p 0.008), absence of otitis or sinusitis (OR 0.44, 95% CI 0.32-0.59, p < 0.001) and S. pneumoniae (OR 2.14, 95% CI 1.55-2.95, p < 0.001) in the multivariate analysis. An unfavourable outcome defined as a score of 1-4 on the Glasgow Outcome Scale was observed in 172 (55%) episodes and 87 patients (28%) died. Pneumonia on admission was independently associated with unfavourable outcome and mortality in the multivariate analysis (OR 1.48, 95% CI 1.12-1.96; p 0.005).

CONCLUSION

Pneumonia on admission in bacterial meningitis is a frequent coexisting infection and is independently associated with unfavourable outcome and mortality.

Recurrent Pneumococcal Meningitis in Children: A Multicenter Case-control Study

BACKGROUND

Pneumococcal meningitis (PM) is a serious disease that can rarely recur at a later time after the initial episode.

METHODS

A retrospective multicenter case-control study was conducted with data for children 18 years of age or younger obtained from the National Observatory of Bacterial Meningitis in Children between January 2001 and September 2015. Cases were all patients with RPM. Each case was matched with 2 randomized controls with a single PM episode in the year of the first episode of PM in the case and born the same year. Case and control data were compared.

RESULTS

Among the 1634 PM episodes in children 18 years of age or younger, 24 (1.5%) children had RPM. RPM cases were significantly less frequent than single PM cases in winter (27% vs. 48%; P=0.03) and showed significantly less concomitant ear, nose and throat infections when considering the first episode (30% vs. 56%, P = 0.04) and all episodes (28% vs. 56%, P < 0.01). Cerebrospinal fluid leakage was frequent in RPM cases versus controls (83% vs. 10%, P < 0.01), including 25% discovered after the third PM episode. Immune deficiency was absent in cases and present in 15% of controls. Cases and controls did not differ in death rate or neurologic outcome.

CONCLUSIONS

RPM is rare in children. Cerebrospinal fluid leakage must be considered.

Anti-inflammatory and Oto-Protective Effect of the Small Heat Shock Protein Alpha B-Crystallin (HspB5) in Experimental Pneumococcal Meningitis

Sensorineural hearing loss is the most common long-term deficit after pneumococcal meningitis (PM), occurring in up to 30% of surviving patients. The infection and the following overshooting inflammatory host response damage the vulnerable sensory cells of the inner ear, resulting in loss of hair cells and spiral ganglion neurons, ultimately leading to elevated hearing thresholds. Here, we tested the oto-protective properties of the small heat shock protein alpha B-crystallin (HspB5) with previously reported anti-inflammatory, anti-apoptotic and neuroprotective functions, in an experimental model of PM-induced hearing loss. We analyzed the effect of local and systemic delivery of HspB5 in an infant rat model of PM, as well as ex vivo, using whole mount cultures. Cytokine secretion profile, hearing thresholds and inner ear damage were assessed at predefined stages of the disease up to 1 month after infection. PM was accompanied by elevated pro-inflammatory cytokine concentrations in the cerebrospinal fluid (CSF), leukocyte and neutrophil infiltration in the perilymphatic spaces of the cochlea with neutrophils extracellular trap formation during the acute phase of the disease. Elevated hearing thresholds were measured after recovery from meningitis. Intracisternal but not intraperitoneal administration of HspB5 significantly reduced the levels of TNF-α, IL-6 IFN-γ and IL-10 in the acute phase of the disease. This resulted in a greater outer hair cell survival, as well as improved hearing thresholds at later stages. These results suggest that high local concentrations of HspB5 are needed to prevent inner ear damage in acute PM. HspB5 represents a promising therapeutic option to improve the auditory outcome and counteract hearing loss after PM.

Epidemiology of central nervous system infectious diseases: a meta-analysis and systematic review with implications for neurosurgeons worldwide

OBJECTIVE

Central nervous system (CNS) infections cause significant morbidity and mortality and often require neurosurgical intervention for proper diagnosis and treatment. However, neither the international burden of CNS infection, nor the current capacity of the neurosurgical workforce to treat these diseases is well characterized. The objective of this study was to elucidate the global incidence of surgically relevant CNS infection, highlighting geographic areas for targeted improvement in neurosurgical capacity.

METHODS

A systematic literature review and meta-analysis were performed to capture studies published between 1990 and 2016. PubMed, EMBASE, and Cochrane databases were searched using variations of terms relating to CNS infection and epidemiology (incidence, prevalence, burden, case fatality, etc.). To deliver a geographic breakdown of disease, results were pooled using the random-effects model and stratified by WHO region and national income status for the different CNS infection types.

RESULTS

The search yielded 10,906 studies, 154 of which were used in the final qualitative analysis. A meta-analysis was performed to compute disease incidence by using data extracted from 71 of the 154 studies. The remaining 83 studies were excluded from the quantitative analysis because they did not report incidence. A total of 508,078 cases of CNS infections across all studies were included, with a total sample size of 130,681,681 individuals. Mean patient age was 35.8 years (range: newborn to 95 years), and the male/female ratio was 1:1.74. Among the 71 studies with incidence data, 39 were based in high-income countries, 25 in middle-income countries, and 7 in low-income countries. The pooled incidence of studied CNS infections was consistently highest in low-income countries, followed by middle- and then high-income countries. Regarding WHO regions, Africa had the highest pooled incidence of bacterial meningitis (65 cases/100,000 people), neurocysticercosis (650/100,000), and tuberculous spondylodiscitis (55/100,000), whereas Southeast Asia had the highest pooled incidence of intracranial abscess (49/100,000), and Europe had the highest pooled incidence of nontuberculous vertebral spondylodiscitis (5/100,000). Overall, few articles reported data on deaths associated with infection. The limited case fatality data revealed the highest case fatality for tuberculous meningitis/spondylodiscitis (21.1%) and the lowest for neurocysticercosis (5.5%). In all five disease categories, funnel plots assessing for publication bias were asymmetrical and suggested that the results may underestimate the incidence of disease.

CONCLUSIONS

This systematic review and meta-analysis approximates the global incidence of neurosurgically relevant infectious diseases. These results underscore the disproportionate burden of CNS infections in the developing world, where there is a tremendous demand to provide training and resources for high-quality neurosurgical care.

Patterns of cerebral tissue oxygen tension and cytoplasmic redox state in bacterial meningitis

BACKGROUND

Compromised cerebral energy metabolism is common in patients with bacterial meningitis. In this study, simultaneous measurements of cerebral oxygen tension and lactate/pyruvate ratio were compared to explore whether disturbed energy metabolism was usually caused by insufficient tissue oxygenation or compromised oxidative metabolism of pyruvate indicating mitochondrial dysfunction.

SUBJECT AND METHODS

Ten consecutive patients with severe streptococcus meningitis were included in this prospective cohort study. Intracranial pressure, brain tissue oxygen tension (PbtO₂ ), and energy metabolism (intracerebral microdialysis) were continuously monitored in nine patients. A cerebral lactate/pyruvate (LP) ratio <30 was considered indicating normal oxidative metabolism, LP ratio >30 simultaneously with pyruvate below lower normal level (70 µmol/L) was interpreted as biochemical indication of ischemia, and LP ratio >30 simultaneously with a normal or increased level of pyruvate was interpreted as mitochondrial dysfunction. The biochemical variables were compared with PbtO₂ simultaneously monitored within the same cerebral region.

RESULTS

In two cases, the LP ratio was normal during the whole study period and the simultaneously monitored PbtO₂ was 18 ± 6 mm Hg. In six cases, interpreted as mitochondrial dysfunction, the simultaneously monitored PbtO₂ was 20 ± 6 mm Hg and without correlation with the LP ratio. In one patient, exhibiting a pattern interpreted as ischemia, PbtO₂ decreased below 10 mm Hg and a correlation between LP and PbtO₂ was observed.

CONCLUSION

This study demonstrated that compromised cerebral energy metabolism, evidenced by increased LP ratio, was common in patients with severe bacterial meningitis while not related to insufficient tissue oxygenation.

Multifaceted Role of Pneumolysin in the Pathogenesis of Myocardial Injury in Community-Acquired Pneumonia

Pneumolysin (PLY), a member of the family of Gram-positive bacterial, cholesterol-dependent, β-barrel pore-forming cytolysins, is the major protein virulence factor of the dangerous respiratory pathogen, Streptococcus pneumoniae (pneumococcus). PLY plays a major role in the pathogenesis of community-acquired pneumonia (CAP), promoting colonization and invasion of the upper and lower respiratory tracts respectively, as well as extra-pulmonary dissemination of the pneumococcus. Notwithstanding its role in causing acute lung injury in severe CAP, PLY has also been implicated in the development of potentially fatal acute and delayed-onset cardiovascular events, which are now recognized as being fairly common complications of this condition. This review is focused firstly on updating mechanisms involved in the immunopathogenesis of PLY-mediated myocardial damage, specifically the direct cardiotoxic and immunosuppressive activities, as well as the indirect pro-inflammatory/pro-thrombotic activities of the toxin. Secondly, on PLY-targeted therapeutic strategies including, among others, macrolide antibiotics, natural product antagonists, cholesterol-containing liposomes, and fully humanized monoclonal antibodies, as well as on vaccine-based preventive strategies. These sections are preceded by overviews of CAP in general, the role of the pneumococcus as the causative pathogen, the occurrence and types of CAP-associated cardiac complication, and the structure and biological activities of PLY.

Adult Patients with Pneumococcal Meningitis at a Neurosurgical Neurologic Center: Different Predisposing Conditions?

BACKGROUND

In previous studies of pneumococcal meningitis in adults within general hospitals or national cohorts, the most common predisposing conditions were otitis media, sinusitis, pneumonia, immunosuppression, alcoholism, and diabetes. The epidemiology of pneumococcal meningitis is changing because of the use of vaccines in childhood, and antibiotic resistance has increased.

METHODS

We retrospectively reviewed the cases of patients with diagnoses of pneumococcal meningitis proved by an inflammatory cerebrospinal fluid (CSF) with a positive culture, treated during a period of 14 years at an adult neurosurgical neurologic referral center. Our aim was to define their clinical course, predisposing conditions, antimicrobial susceptibilities, and outcome.

RESULTS

We reviewed the cases of 30 patients, 17 men and 13 women, with a mean age of 36.7 years. Fourteen patients (46.6%) had previous neurosurgery, 12 patients (40%) had CSF fistula, 8 had remote head trauma, and 8 also presented recurrent meningitis. Resistance to ceftriaxone or vancomycin was less than 5%, and penicillin resistance was 53%. Eight patients (26.7%) had died. An increased risk of death was associated with coma at admission, septic shock, upper gastrointestinal bleeding, mechanical ventilation, thrombocytopenia, and a low CSF opening pressure.

CONCLUSIONS

We conclude that patients with pneumococcal meningitis treated at neurosurgical neurologic centers have different predisposing conditions with severe disease and high mortality, thus prompting us to recommend aggressive pneumococcal vaccination in patients with CSF leaks and severe head trauma. Prospective studies to identify which neurosurgical patients may benefit in the long term from a pneumococcal vaccine are urgently needed.

Use of intracranial pressure monitoring in bacterial meningitis: a 10-year follow up on outcome and intracranial pressure versus head CT scans

BACKGROUND

The aim of this study was to evaluate the clinical outcome of patients with severe bacterial meningitis where intracranial pressure (ICP) monitoring has been performed.

METHODS

A retrospective observational study including patients admitted 1st^. January 2005 to 31st^. December 2014. Thirty nine patients age 18-89 years were included. All the patients received intensive care with mechanical ventilation, ICP monitoring, sedation, antibiotics and corticosteroids according to current guidelines. Clinical outcome was defined as death during hospitalization or survival at hospital discharge.

RESULTS

The most common pathogen was Streptococcus pneumoniae (26; 67%). Thirteen patients died (33%) and neurologic impairment was noted in twenty two (84.6%) surviving patients. In S. pneumoniae cases patients with adverse outcome were significantly older (p = 0.0024) and immunosuppressed (p = 0.034). Lower mean-cerebral perfusion pressure (CPP) was found to correlate with adverse outcome (p = 0.005). Cerebrospinal fluid (CSF) was drained in fourteen patients. Increased ICP (>20 mmHg) was observed in twenty four patients. No significant correlation was found between measured ICP and head CT scans with signs of elevated ICP.

CONCLUSIONS

Patients with severe meningitis should be admitted to intensive care units and evaluated for ICP monitoring regardless of head CT findings.

Adjunctive dexamethasone therapy in unconfirmed bacterial meningitis in resource limited settings: is it a risk worth taking?

BACKGROUND

Bacterial meningitis is associated with significant morbidity and mortality despite advances in medical care. The main objective of this study was to assess the association of adjunctive dexamethasone treatment with discharge outcome of patients treated as bacterial meningitis in low income setting.

METHODS

A retrospective study was conducted at four teaching hospitals across Ethiopia. Patients of age 14 years and older treated as cases of bacterial meningitis between January 1, 2011 and April 30, 2015 were included in this study. Information regarding sociodemographic data, clinical presentations, laboratory data, treatments given and status at hospital discharge were retrieved from patients' medical records using a structured questionnaire. Predefined outcome variables at discharge were analysed using descriptive statistics. Multivariable logistic regression was used to identify factors independently associated with poor outcome.

RESULTS

A total of 425 patients treated with the presumptive clinical diagnosis of bacterial meningitis were included in this study (lumbar puncture done in 56 %; only 19 % had CSF findings compatible with bacterial meningitis, and only 3 % had proven etiology). The overall in hospital mortality rate was 20.2 %. Impaired consciousness, aspiration pneumonia, and cranial nerve palsy at admission were independently associated with increased mortality. Adjuvant dexamethasone, which was used in 50.4 % of patients, was associated with increased in-hospital mortality (AOR = 3.38; 95 % CI 1.87-6.12, p < 0.001) and low Glasgow outcome scale (GOS) at discharge (AOR = 4.46 (95 % CI 1.98-10.08). This association between dexamethasone and unfavorable outcome was found to be more pronounced in suspected but unproven cases and in those without CSF alterations compatible with bacterial meningitis.

CONCLUSION

Most patients treated for suspected bacterial meningitis did not receive proper diagnostic workup. Adjuvant dexamethasone use in clinically suspected but unproven cases of bacterial meningitis was associated with an increased mortality and poor discharge GOS. These findings show that there are potential deleterious effects in unconfirmed cases in this setting. Physicians practising under such circumstances should thus abide with the current recommendation and defer the use of adjuvant corticosteroid in suspected cases of bacterial meningitis.

Neurological sequelae of bacterial meningitis

OBJECTIVES

We reported on occurrence and impact of neurological sequelae after bacterial meningitis.

METHODS

We reviewed occurrence of neurological sequelae in children and adults after pneumococcal and meningococcal meningitis.

RESULTS

Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive impairment and epilepsy. Adults with pneumococcal meningitis have the highest risk of developing focal neurological deficits, which are most commonly caused by cerebral infarction, but can also be due to cerebritis, subdural empyema, cerebral abscess or intracerebral bleeding. Focal deficits may improve during clinical course and even after discharge, but a proportion of patients will have persisting focal neurological deficits that often interfere in patient's daily life. Hearing loss occurs in a high proportion of patients with pneumococcal meningitis and has been associated with co-existing otitis. Children and adults recovering from bacterial meningitis without apparent neurological deficits are at risk for long-term cognitive deficits. Early identification of neurological sequelae is important for children to prevent additional developmental delay, and for adults to achieve successful return in society after the disease.

CONCLUSIONS

Neurological sequelae occur in a substantial amount of patients following bacterial meningitis. Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive impairment and epilepsy.

Patterns of Local and Systemic Cytokines in Bacterial Meningitis and its Relation with Severity and Long-Term Sequelae

Bacterial meningitis (BM) is a pyogenic infection present in the subarachnoid space, potentially fatal and frequently associated with neurological sequelae. During BM, cytokines (CTs) are locally produced. We sought to determine the CTs' clinical role as disease severity predictors in adults, which is not completely clear. Using a bead-based flow cytometric assay, levels of six CTs were determined in cerebrospinal fluid (CSF) and plasma from 18 adult BM patients and 19 uninfected controls. Long-term neurological sequelae were evaluated using the Glasgow Outcome Scale (GOS). All evaluated CTs were higher in CSF than in plasma, and the levels of CSF interleukin (IL)-6, IL-8, IL-10, IL-1β, and tumor necrosis factor-α and plasma IL-10 and IL-12p70 were significantly higher in patients with severe sepsis than with sepsis, suggesting an association with clinical severity. There was a strong negative correlation between CSF IL-6 and plasma IL-12p70 with GOS score, supporting the possible role of these CTs in the development of neurological long-term sequelae. These findings could be helpful to identify candidates to receive neuroprotective treatments and early physiotherapy schemes.

Clinical Prognosis in Neonatal Bacterial Meningitis: The Role of Cerebrospinal Fluid Protein

Neonates are at high risk of meningitis and of resulting neurologic complications. Early recognition of neonates at risk of poor prognosis would be helpful in providing timely management. From January 2008 to June 2014, we enrolled 232 term neonates with bacterial meningitis admitted to 3 neonatology departments in Shanghai, China. The clinical status on the day of discharge from these hospitals or at a postnatal age of 2.5 to 3 months was evaluated using the Glasgow Outcome Scale (GOS). Patients were classified into two outcome groups: good (167 cases, 72.0%, GOS = 5) or poor (65 cases, 28.0%, GOS = 1–4). Neonates with good outcome had less frequent apnea, drowsiness, poor feeding, bulging fontanelle, irritability and more severe jaundice compared to neonates with poor outcome. The good outcome group also had less pneumonia than the poor outcome group. Besides, there were statistically significant differences in hemoglobin, mean platelet volume, platelet distribution width, C-reaction protein, procalcitonin, cerebrospinal fluid (CSF) glucose and CSF protein. Multivariate logistic regression analyses suggested that poor feeding, pneumonia and CSF protein were the predictors of poor outcome. CSF protein content was significantly higher in patients with poor outcome. The best cut-offs for predicting poor outcome were 1,880 mg/L in CSF protein concentration (sensitivity 70.8%, specificity 86.2%). After 2 weeks of treatment, CSF protein remained higher in the poor outcome group. High CSF protein concentration may prognosticate poor outcome in neonates with bacterial meningitis.

Streptococcus pneumoniae Serotypes and Mortality in Adults and Adolescents in South Africa: Analysis of National Surveillance Data, 2003 - 2008

BACKGROUND

An association between pneumococcal serotypes and mortality has been suggested. We aimed to investigate this among individuals aged ≥15 years with invasive pneumococcal disease (IPD) in South Africa.

METHODS

IPD cases were identified through national laboratory-based surveillance at 25 sites, pre-pneumococcal conjugate vaccine (PCV) introduction, from 2003-2008. We assessed the association between the 20 commonest serotypes and in-hospital mortality using logistic regression with serotype 4 (the third commonest serotype with intermediate case-fatality ratio (CFR)) as referent.

RESULTS

Among 3953 IPD cases, CFR was 55% (641/1166) for meningitis and 23% (576/2484) for bacteremia (p<0.001). Serotype 19F had the highest CFR (48%, 100/207), followed by serotype 23F (39%, 99/252) and serotype 1 (38%, 246/651). On multivariable analysis, factors independently associated with mortality included serotype 1 (OR 1.9, 95%CI 1.1-3.5) and 19F (OR 2.9, 95%CI 1.4-6.1) vs. serotype 4; increasing age (25-44 years, OR 1.8, 95%CI 1.0-3.0; 45-64 years, OR 3.6, 95%CI 2.0-6.4; ≥65 years, OR 5.2, 95%CI 1.9-14.1; vs. 15-24 years); meningitis (OR 4.1, 95%CI 3.0-5.6) vs. bacteremic pneumonia; and HIV infection (OR1.7, 95%CI 1.0-2.8). On stratified multivariate analysis, serotype 19F was associated with increased mortality amongst bacteremic pneumococcal pneumonia cases, while no serotype was associated with increased mortality in meningitis cases.

CONCLUSION

Mortality was increased in HIV-infected individuals, which may be reduced by increased antiretroviral therapy availability. Serotypes associated with increased mortality are included in the 10-and-13-valent PCV and may become less common in adults due to indirect effects following routine infant immunization.

Pathogens penetrating the central nervous system: infection pathways and the cellular and molecular mechanisms of invasion

The brain is well protected against microbial invasion by cellular barriers, such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). In addition, cells within the central nervous system (CNS) are capable of producing an immune response against invading pathogens. Nonetheless, a range of pathogenic microbes make their way to the CNS, and the resulting infections can cause significant morbidity and mortality. Bacteria, amoebae, fungi, and viruses are capable of CNS invasion, with the latter using axonal transport as a common route of infection. In this review, we compare the mechanisms by which bacterial pathogens reach the CNS and infect the brain. In particular, we focus on recent data regarding mechanisms of bacterial translocation from the nasal mucosa to the brain, which represents a little explored pathway of bacterial invasion but has been proposed as being particularly important in explaining how infection with Burkholderia pseudomallei can result in melioidosis encephalomyelitis.

The burden of pneumococcal meningitis in Austrian children between 2001 and 2008

The present study was conducted to evaluate the burden of pneumococcal meningitis in Austrian children between 2001 and 2008. Clinical outcome was retrospectively analyzed both on discharge and on follow-up investigations. This study was based on a prospective multicentre surveillance study on hospitalized invasive pneumococcal infections in Austrian children with a total annual "study population" of about 399,000 children aged below 5 years per year. Between 2001 and 2008, 74 cases of pneumococcal meningitis were identified in children aged below 5 years. The mean annual incidence rate for pneumococcal meningitis was 2.3 per 100,000 children in this age group. In 57/74 children (mean age on admission 14.5 ± 13.3 months), outcome data on hospital discharge were available: 5 deaths (8.8%), 20 children (35.1%) with sequelae and 32 children (56.1%) without sequelae were observed. Sequelae on discharge included motor impairment in 8 children (14.0%), hearing impairment in 9 children (15.8%) and/or other complications in 14 children (24.6%). In 7/8 children with motor deficits, matching cerebral lesions were identified by neuroimaging: cerebral infarction in five children, cerebral vasculitis and cerebral abscess in one child each. In 40/57 children, long-term outcome (18.9 ± 20.2 months after discharge) could be assessed: 1 child (2.5%) died 9 months after hospital discharge, 11 children (27.5%) had one or two long-term sequelae and 28 children (70.0%) had no sequelae. Long-term sequelae included motor impairment in three children (7.5%), hearing impairment in nine children (22.5%) and other deficits in two children (5.0%).

CONCLUSION

Our study confirms that pneumococcal meningitis causes high mortality and severe long-term sequelae. On long-term follow-up, we observed improvements of motor impairment, but not of hearing impairment.

The kynurenine pathway contributes to long-term neuropsychological changes in experimental pneumococcal meningitis

Pneumococcal meningitis is a lethal form of bacterial infection in the central nervous system that often causes lifelong neurological sequelae, despite therapeutic advances. The contemporary view is that the inflammatory response to infection contributes to the functional disabilities among survivors of this disease. We previously have established a mouse model of neurobehavioural deficits, using an automated IntelliCage™ system that revealed long-term behavioural and cognitive deficits in C57BL/6J female mice cured of meningitis by ceftriaxone treatment. We now have investigated the roles of two kynurenine pathway enzymes, indoleamine dioxygenase-1 (IDO1) and tryptophan dioxygenase-2 (TDO2), in the pathomechanisms of pneumococcal meningitis. Since tryptophan metabolism has long been implicated in behavioural and cognitive modulation through the production of neuroactive compounds, we hypothesised that preventing the actions of these enzymes through gene knockout would be beneficial in mice subjected to pneumococcal infection. We found no significant effect of IDO1 or TDO2 on mortality. Post-meningitic wild-type mice showed long-term diurnal hypoactivity and nocturnal hyperactivity when they were exposed to an Intellicage adaptation test throughout both the light and dark phases. These changes were not apparent in IDO1(-/-) survivors, but were present in the TDO2(-/-) survivors. Both IDO1(-/-) and TDO2(-/-) survivors were not protected against developing long-term cognitive deficits as measured in IntelliCage-based patrolling or reversal tasks. Collectively, these observations suggest (i) involvement of the kynurenine pathway in causing some behavioural sequelae of pneumococcal meningitis and (ii) that this pathway might operate synergistically with, or independently of, other pathways to cause other aspects of neurological sequelae.

Increase in hippocampal water diffusion and volume during experimental pneumococcal meningitis is aggravated by bacteremia

Background

The hippocampus undergoes apoptosis in experimental pneumococcal meningitis leading to neurofunctional deficits in learning and memory function. The aim of the present study was 1) to investigate hippocampal apparent diffusion coefficient (ADC) and volume with MRI during the course of experimental pneumococcal meningitis, 2) to explore the influence of accompanying bacteremia on hippocampal water distribution and volume, 3) and to correlate these findings to the extent of apoptosis in the hippocampus.

Methods

Experimental meningitis in rats was induced by intracisternal injection of live pneumococci. The study comprised of four experimental groups. I. Uninfected controls (n = 8); II. Meningitis (n = 11); III. Meningitis with early onset bacteremia by additional i.v. injection of live pneumococci (n = 10); IV. Meningitis with attenuated bacteremia by treatment with serotype-specific anti-pneumococcal antibodies (n = 14). T2 and diffusion weighted MR images were used to analyze changes in hippocampus volume and water diffusion (ADC). The results were correlated to ADC of the cortex, to ventricular volume, and to the extent of hippocampal apoptosis.

Results

Both ADC and the volume of hippocampus were significantly increased in meningitis rats compared to uninfected controls (Kruskal-Wallis test, p = 0.0001, Dunns Post Test, p < 0.05), and were significantly increased in meningitis rats with an early onset bacteremia as compared to meningitis rats with attenuated bacteremia (p < 0.05). Hippocampal ADC and the volume and size of brain ventricles were positively correlated (Spearman Rank, p < 0.05), whereas no association was found between ADC or volume and the extent of apoptosis (p > 0.05).

Conclusions

In experimental meningitis increase in volume and water diffusion of the hippocampus are significantly associated with accompanying bacteremia.

Pneumococcal meningitis in children: epidemiology, serotypes, and outcomes from 1997-2010 in Utah

BACKGROUND

After licensure of the 7-valent pneumococcal conjugate vaccine (PCV7) in the United States in 2000, the incidence of pediatric pneumococcal meningitis decreased significantly. However, cases continue to occur. It is unknown whether meningitis due to PCV7 and non-PCV7 serotypes causes similar morbidity and mortality.

METHODS

We performed a retrospective cohort study of laboratory-confirmed pneumococcal meningitis among Utah children from 1997 to 2010. We reviewed medical records and obtained clinical data during the acute illness and follow-up data on neurologic sequelae.

RESULTS

Sixty-eight cases of meningitis were identified. PCV7 serotypes caused 64% of cases before and 25% of cases after licensure of PCV7 (P < .01). The age range was similar before and after PCV7 licensure (P = .5). The overall case fatality rate was 13% and was similar among cases caused by PCV7 and non-PCV7 serotypes (P = .7). Children with PCV7 serotypes were more likely to require mechanical ventilation (68% vs 34%; P < .01). Of all survivors, 63% had neurologic sequelae, and the proportion was similar after infection with PCV7 or non-PCV7 serotypes (P = .1). More than one-half (54%) of all children who developed pneumococcal meningitis in the PCV7 period were eligible for PCV7 and had not been immunized.

CONCLUSIONS

Pneumococcal meningitis continues to be associated with high mortality and morbidity; death and neurologic sequelae are common with both PCV7 and non-PCV7 serotype meningitis. The substantial burden of this disease and continued cases among unimmunized children reinforce the need for more effective immunization strategies and continued surveillance in the era of PCV13.

Pathophysiology of acute meningitis caused by Streptococcus pneumoniae and adjunctive therapy approaches

Pneumococcal meningitis is a life-threatening disease characterized by an acute purulent infection affecting piamater, arachnoid and the subarachnoid space. The intense inflammatory host's response is potentially fatal and contributes to the neurological sequelae. Streptococcus pneumoniae colonizes the nasopharynx, followed by bacteremia, microbial invasion and blood-brain barrier traversal. S. pneumoniae is recognized by antigen-presenting cells through the binding of Toll-like receptors inducing the activation of factor nuclear kappa B or mitogen-activated protein kinase pathways and subsequent up-regulation of lymphocyte populations and expression of numerous proteins involved in inflammation and immune response. Many brain cells can produce cytokines, chemokines and others pro-inflammatory molecules in response to bacteria stimuli, as consequence, polymorphonuclear are attracted, activated and released in large amounts of superoxide anion and nitric oxide, leading to the peroxynitrite formation, generating oxidative stress. This cascade leads to lipid peroxidation, mitochondrial damage, blood-brain barrier breakdown contributing to cell injury during pneumococcal meningitis.

B7-H3 participates in the development of experimental pneumococcal meningitis by augmentation of the inflammatory response via a TLR2-dependent mechanism

In addition to a well-documented role in regulating T cell-mediated immune responses, B7-H3, a newly discovered member of the B7 superfamily, has been recently identified as a costimulator in the innate immunity-mediated inflammatory response. In this study, we further report that B7-H3 participates in the development of pneumococcal meningitis in a murine model. Exogenous administration of B7-H3 strongly amplified the inflammatory response, exacerbated blood-brain barrier disruption, and aggravated the clinical disease status in Streptococcus pneumoniae-infected C3H/HeN wild-type mice. Consistent with the in vivo findings, B7-H3 substantially augmented proinflammatory cytokine and chemokine production, upregulated NF-κB p65 and MAPK p38 phosphorylation, and enhanced the nuclear transactivation of NF-κB p65 at both TNF-α and IL-6 promoters in S. pneumoniae-stimulated primary murine microglia cells. These B7-H3-associated in vitro and in vivo effects appeared to be dependent on TLR2 signaling, as B7-H3 almost completely lost its amplifying actions in both TLR2-deficient microglial cells and TLR2-deficient mice. Furthermore, administration of the anti-B7-H3 mAb (MIH35) attenuated the inflammatory response and ameliorated blood-brain barrier disruption in S. pneumoniae-infected wild-type mice. Collectively, our results indicate that B7-H3 plays a contributory role in the development of S. pneumoniae infection-induced bacterial meningitis.

Surgical treatment of neurologic complications of bacterial meningitis in children in Kosovo

Neurologic complications of bacterial meningitis can occur any time during the course of the disease and some of them need neurosurgical aproach.

OBJECTIVE

to determine the incidence of neurologic complications of bacterial meningitis in children requring neurosurgical treatment.

MATERIAL AND METHODOLOGY

a total of 277 children were followed and treated for bacterial meningitis at the Clinic of Infectious Diseases in Prishtina. The authors have analyzed cases who developed acute neurologic complications and treatment procedures.

RESULTS

of the 277 children treated for bacterial meningitis, due to the suspicion for neurologic complications, 109 children underwent a head computerized tomography scan. About 47 cases (43%) had evident structural abnormalities while only 15/277 cases (5%) required neurosurgical treatment; 9/38 cases with subdural collections, 5 cases with hydrocephalus and 1 case of spinal abscess.

CONCLUSION

Neurosurgical intervention were not common in pediatric bacterial meningitis cases (5%) but were highly significant in cases complicated with acute neurologic complications (32%).

Prognostic accuracy of five simple scales in childhood bacterial meningitis

BACKGROUND

In childhood acute bacterial meningitis, the level of consciousness, measured with the Glasgow coma scale (GCS) or the Blantyre coma scale (BCS), is the most important predictor of outcome. The Herson-Todd scale (HTS) was developed for Haemophilus influenzae meningitis. Our objective was to identify prognostic factors, to form a simple scale, and to compare the predictive accuracy of these scales.

METHODS

Seven hundred and twenty-three children with bacterial meningitis in Luanda were scored by GCS, BCS, and HTS. The simple Luanda scale (SLS), based on our entire database, comprised domestic electricity, days of illness, convulsions, consciousness, and dyspnoea at presentation. The Bayesian Luanda scale (BLS) added blood glucose concentration. The accuracy of the 5 scales was determined for 491 children without an underlying condition, against the outcomes of death, severe neurological sequelae or death, or a poor outcome (severe neurological sequelae, death, or deafness), at hospital discharge.

RESULTS

The highest accuracy was achieved with the BLS, whose area under the curve (AUC) for death was 0.83, for severe neurological sequelae or death was 0.84, and for poor outcome was 0.82. Overall, the AUCs for SLS were ≥0.79, for GCS were ≥0.76, for BCS were ≥0.74, and for HTS were ≥0.68.

CONCLUSIONS

Adding laboratory parameters to a simple scoring system, such as the SLS, improves the prognostic accuracy only little in bacterial meningitis.

Mortality from bacterial meningitis in children in Kosovo

Bacterial meningitis is a severe infection responsible for high mortality. This prospective study of 277 pediatric bacterial meningitis cases was done to identify factors predicting death in children <16 years of age living and treated in a limited-resources country (Kosovo). Of the 277 children enrolled, 60 patients (22%) developed neurologic complications, and 15 children died (5%). The following variables were strongly correlated with mortality: altered mental status on admission (relative risk [RR] = 29.9), presentation of the initial cerebrospinal fluid as thick pus (RR = 29.9), prehospital seizures (RR = 23.5) and their recurrence >24 hours after admission (RR = 11.5), age <1 month (RR = 19.3), the use of inotropic agents (RR = 11.5), and admission after 5 days' duration of illness (P < .001). The mortality rate in children in Kosovo is similar to those reported from developing countries, and this is most likely due to the unfavorable living conditions.

Increased risk of death in human immunodeficiency virus-infected children with pneumococcal meningitis in South Africa, 2003-2005

BACKGROUND

Pneumococcal disease is a major global cause of morbidity and mortality. This study evaluated risk factors for mortality in children with pneumococcal meningitis and other invasive pneumococcal diseases (IPD).

METHODS

The study population included patients <15 years of age with laboratory-confirmed IPD and available outcome data between January 1, 2003 and December 31, 2005 as reported to a national laboratory-based surveillance program. Meningitis was defined by having pneumococcus identified from cerebrospinal fluid culture, while other IPD included patients with pneumococci identified from other normally sterile site specimens. Risk factors for mortality were evaluated using multivariable logistic regression.

RESULTS

A total of 2251 patients with IPD were reported from sentinel sites: 581 with laboratory-confirmed meningitis and 1670 with other IPD. The case-fatality ratio was 35% (205/581) among meningitis cases and 18% (300/1670) among other IPD cases (P < 0.001). Among individuals with available human immunodeficiency virus (HIV) status data, HIV coinfection was less likely among patients with meningitis compared with other IPD (74% [244/328] vs. 82% [880/1067] P < 0.001). On multivariable analysis, HIV-infected status (odds ratio [OR]: 5.34, 95% confidence interval [CI]: 2.32-12.29), Pitt bacteremia score ≥4 (OR: 3.08, 95% CI: 1.21-7.83) and age group <1 year (OR: 2.58, 95% CI: 1.21-5.51) were independent predictors of death among patients with meningitis. Among children with other IPD, malnutrition was an independent predictor of death while HIV infection was not independently associated with increased risk of death.

CONCLUSIONS

Pneumococcal meningitis is associated with a high case-fatality ratio among South African children and this is increased by HIV coinfection. Increasing access to antiretroviral therapy and a catch-up program for pneumococcal conjugate vaccine among HIV-infected and malnourished children could reduce this excess mortality.