Bacterial meningitis--a view of the past 90 years

An Integrative Approach to Investigate the Mode of Action of (-)-Dendroparishiol in Bacterial Meningitis: Computer-Aided Estimation of Biological Activity and Network Pharmacology

Bacterial meningitis remains one of the most prevalent infectious diseases worldwide. Although advances in medical care have improved mortality and morbidity, neurological complications remain high. Therefore, aside from antibiotics, therapeutic adjuvants targeting neuroinflammation are essential to combat the long-term neuronal sequelae of bacterial meningitis. In the present study, we propose (-)-dendroparishiol as a potential add-on therapy to improve neuroinflammation associated with bacterial meningitis. The biological activity of (-)-dendroparishiol was first predicted by computational analysis and further confirmed in vitro using a cell-based assay with LPS-induced BV-2 microglial cells. Biological pathways involved with (-)-dendroparishiol were identified by applying network pharmacology. Computational predictions of biological activity indicated possible attenuation of several inflammatory processes by (-)-dendroparishiol. In LPS-induced BV-2 microglial cells, (-)-dendroparishiol significantly reduced the expression of inflammatory mediators: iNOS, NO, COX-2, IL-6, and TNF-α. Molecular docking results demonstrated the potential iNOS and COX-2 inhibitory activity of (-)-dendroparishiol. Network pharmacological analysis indicated the plausible role of (-)-dendroparishiol in biological processes involved in oxidative stress and neuroinflammation with enrichment in neuroinflammatory pathways. Overall, this study provides scientific evidence for the potential application of (-)-dendroparishiol in the management of bacterial meningitis-associated neuroinflammation.

Mid-term health-related quality of life in community-acquired bacterial meningitis survivors; the COMBAT study

BACKGROUND

Community Acute Bacterial Meningitis (CABM) is a rare infectious disease leading to important impairments. Our aim was to describe CABM survivors' quality of life (QOL) 12 months post-CABM and to assess its associations with CABM sequelae.

METHODS

Patients included in the CABM COMBAT cohort were evaluated one year after the CABM episode. Data were collected by questionnaire, via phone calls with the patients. The WHOQOL-BREF was used to measure CABM survivors' QOL. Hierarchical multivariate linear regressions were performed.

RESULTS

Study population was composed of 284 patients. At 12 months, 53.9% (153/284) reported at least incident headache/worsening headache intensity at 12 months post-CABM, and/or incident hearing impairment, and/or unfavourable disability outcome (GOS). Unfavourable disability outcome was associated with lower physical health QOL (B = -30.35, p<0.001), lower mental health QOL (B = -15.31, p<0.001), lower environmental QOL (B = -11.08, p<0.001) and lower social relationships QOL (B = -9.62, p<0.001). Incident headache/worsening headache since meningitis onset was associated with lower psychological health (B = -5.62, p = 0.010). Incident hearing impairment was associated with lower physical QOL (B = -5.34, p = 0.030). Hierarchical regressions showed that CABM impairments significantly increase explanatory power of multivariate models (for physical health R2 change = 0.42, p<0.001, for psychological health R2 change = 0.23, p<0.001, for social relationships R2 change = 0.06, p<0.001 and for environment domain R2 change was 0.15, p<0.001).

CONCLUSIONS

12 month-CABM burden is heavy. Early detection and management of CABM impairments should be performed in clinical practice as early as possible to optimize patients' psychological and psychosocial functioning.

CLINICALTRIAL. GOV IDENTIFICATION NUMBER

NCT01730690.

Spinal canal infection caused by Streptococcus suis in human: a case report

Background

Streptococcus suis is an emerging zoonotic pathogen that mainly causes meningitis, sepsis, arthritis, endocarditis, and endophthalmitis in human. To the best of our knowledge, Spinal canal infection caused by Streptococcus suis has rarely been reported.

Case presentation

Here we report a case of spinal canal infection caused by Streptococcus suis in a 50-year-old male patient. The patient had a history of close contact with sick pigs days before disease onset. Initially he presented with headache and fever. After admission, the patient began to experience lower back pain, which led physicians to perform a lumber puncture. Meta-genomic next generation sequencing helped identify Streptococcus suis in the cerebrospinal fluid. MRI imaging indicated a spinal canal infection caused by Streptococcus suis.

Conclusions

Spinal canal infection is an uncommon disease of Streptococcus suis infection. This case report indicates that people presented with fever, headache and lower back pain should also be suspected as Streptococcus suis infection, especially for those who have had a history of sick pig contact.

Penicillin- and third-generation cephalosporin-resistant strains of Streptococcus pneumoniae meningitis: Case report and literature review

BACKGROUND

Treatment of patients with penicillin-resistant S. pneumoniae (PRSP) is complicated because of the relatively poor blood-brain barrier penetration of effective antimicrobials. Our case: A previously healthy 70-year-old woman, a traveler from China to Japan, was admitted to our hospital with fever and loss of consciousness. She has no history of pneumococcal vaccination. She was diagnosed with bacterial meningitis due to penicillin-and third-generation cephalosporin-resistant strains of S. pneumoniae. The patient was successfully treated with a combination therapy of vancomycin (VCM) and levofloxacin (LVFX) and recovered without any neurological sequelae. As the treatment of penicillin-and third-generation cephalosporin-resistant strains of S. pneumoniae meningitis remains unclear, we conducted a review of the reported cases of meningitis caused by penicillin- and cephalosporin-resistant S. pneumoniae.

METHOD

We performed a search using the keywords "penicillin-resistant Streptococcus pneumoniae," "meningitis," and "pneumococcal meningitis". We searched the electronic databases PubMed, Embase, and Ichushi from their inception to March 2020. Subsequently, two authors independently reviewed the resulting database records, retrieved full texts for eligibility assessment, and extracted data from these cases.

RESULT

We identified 18 papers describing thirty-five cases of penicillin- and cephalosporin-resistant S. pneumoniae meningitis including our case. The patient's characteristics were; median age: 50 years, men:50%, 85% of cases received combination regimens of antibiotics: Ceftroriaxone (CTRX) plus VCM (20 cases), CTRX plus VCM plus rifampicin (RFP) (two cases), CTRX plus linezolid (one case), fluoroquinolones (two cases), carbapenems (six cases), Thirty-five percent received steroids. Twenty-four percent of patients died. Twenty-six percent of patients complicated neurological sequalae.

CONCLUSION

Combination therapy including VCM plus LVFX could be a treatment option.

Existing Data Sources for Clinical Epidemiology: The Danish Study Group of Infections of the Brain Database (DASGIB)

Central nervous system (CNS) infections are rare diseases that are associated with considerable morbidity and mortality. Increased knowledge based on contemporary data is a prerequisite for improved management and prevention of these serious conditions. Yet, population-based databases of patients hospitalized with CNS infections remain scarce. The Danish Study Group of Infections of the Brain (DASGIB) has prospectively registered information on all adults ≥18 years of age admitted with CNS infections at departments of infectious diseases in Denmark since 2015. The main variables collected are baseline demographics, blood and cerebrospinal fluid tests, imaging results, and outcome using the Glasgow Outcome Scale score. To investigate important aspects for each type of CNS infections, additional variables are included specifically for bacterial meningitis, viral meningitis, encephalitis, brain abscess, neurosyphilis, and Lyme neuroborreliosis. From 2015 to 2020, a total of 3579 cases of CNS infections have been recorded in the DASGIB database. Using the unique civil registration number assigned to all Danish residents, the database can be unambiguously linked with nationwide healthcare registries at the individual level. This enables researchers to conduct detailed population-based and longitudinal observational studies of risk and prognosis of CNS infections and to compare them with matched population cohorts. The database is well-suited for epidemiological research and the DASGIB network forms a solid infrastructure for future national and international collaborations.

Meningococcus, this famous unknown

Neisseria meningitidis (meningococcus) is a Gram-negative bacterium responsible for two devastating forms of invasive diseases: purpura fulminans and meningitis. Since the first description of the epidemic nature of the illness at the dawn of the nineteenth century, the scientific knowledge of meningococcal infection has increased greatly. Major advances have been made in the management of the disease with the advent of antimicrobial therapy and the implementation of meningococcal vaccines. More recently, an extensive knowledge has been accumulated on meningococcal interaction with its human host, revealing key processes involved in disease progression and new promising therapeutic approaches.

Estimating the economic burden of pneumococcal meningitis and pneumonia in northern Ghana in the African meningitis belt post-PCV13 introduction

BACKGROUND

Ghana introduced 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant immunization program in 2012, using a three-dose primary series without a booster. Despite ≥ 88% reported three-dose vaccination coverage since 2013, PCV13-type pneumococcal meningitis outbreaks have occurred. We estimated the ongoing economic burden of PCV13-type pneumococcal meningitis and pneumonia in northern Ghana, an area within the African meningitis belt with seasonal increases of pneumococcal meningitis post-PCV13 introduction, to inform PCV13 vaccination policy.

METHODS

We performed a cross-sectional survey among patients with pneumonia or meningitis at three hospitals in northern Ghana to determine patient-level costs (direct medical and nonmedical, indirect patient and caregiver costs) incurred in household, outpatient, and inpatient settings. Pneumonia burden was estimated using 2017-2018 administrative records. Pneumococcal meningitis burden was estimated using 2017-2018 case-based surveillance data. Economic burden was reported in 2019 U.S. dollars ($) from the societal perspective.

RESULTS

For an area with a total population of 5,068,521, our model estimated 6,441 PCV13-type pneumonia cases and 286 PCV13-type meningitis cases occurred in a typical year post-PCV13. In the base case scenario, the total economic burden was $5,230,035 per year ($777 per case). By age group, cost per PCV13-type pneumonia case was $423 (<5 years), $911 (5-14 years), and $784 (≥15 years); cost per PCV13-type meningitis case was $2,128 (<5 years), $3,247 (5-14 years), and $2,883 (≥15 years). Most (78.0-93.4%) of the total societal cost was due to indirect costs related to deaths from PCV13-type diseases.

CONCLUSIONS

The estimated economic burden of PCV13-type disease in northern Ghana remains substantial, especially in older children and adults who were expected to have benefited from indirect effects from infant immunization. Additional interventions such as changes in the infant immunization schedule, reactive vaccination, or catch-up PCV13 vaccination may be needed to control remaining vaccine-type disease.

Neuronal Damage and Neuroinflammation, a Bridge Between Bacterial Meningitis and Neurodegenerative Diseases

Bacterial meningitis is an inflammation of the meninges which covers and protects the brain and the spinal cord. Such inflammation is mostly caused by blood-borne bacteria that cross the blood-brain barrier (BBB) and finally invade the brain parenchyma. Pathogens such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae are the main etiological causes of bacterial meningitis. After trafficking across the BBB, bacterial pathogens in the brain interact with neurons, the fundamental units of Central Nervous System, and other types of glial cells. Although the specific molecular mechanism behind the interaction between such pathogens with neurons is still under investigation, it is clear that bacterial interaction with neurons and neuroinflammatory responses within the brain leads to neuronal cell death. Furthermore, clinical studies have shown indications of meningitis-caused dementia; and a variety of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and Huntington's disease are characterized by the loss of neurons, which, unlike many other eukaryotic cells, once dead or damaged, they are seldom replaced. The aim of this review article is to provide an overview of the knowledge on how bacterial pathogens in the brain damage neurons through direct and indirect interactions, and how the neuronal damage caused by bacterial pathogen can, in the long-term, influence the onset of neurodegenerative disorders.

The Global Burden of Meningitis in Children: Challenges with Interpreting Global Health Estimates

The World Health Organization (WHO) has developed a global roadmap to defeat meningitis by 2030. To advocate for and track progress of the roadmap, the burden of meningitis as a syndrome and by pathogen must be accurately defined. Three major global health models estimating meningitis mortality as a syndrome and/or by causative pathogen were identified and compared for the baseline year 2015. Two models, (1) the WHO and the Johns Hopkins Bloomberg School of Public Health’s Maternal and Child Epidemiology Estimation (MCEE) group’s Child Mortality Estimation (WHO-MCEE) and (2) the Institute for Health Metrics and Evaluation (IHME) Global Burden of Disease Study (GBD 2017), identified meningitis, encephalitis and neonatal sepsis, collectively, to be the second and third largest infectious killers of children under five years, respectively. Global meningitis/encephalitis and neonatal sepsis mortality estimates differed more substantially between models than mortality estimates for selected infectious causes of death and all causes of death combined. Estimates at national level and by pathogen also differed markedly between models. Aligning modelled estimates with additional data sources, such as national or sentinel surveillance, could more accurately define the global burden of meningitis and help track progress against the WHO roadmap.

Transcranial Doppler Ultrasonographic Evaluation of Cerebrovascular Abnormalities in Children With Acute Bacterial Meningitis

Introduction: Bacterial meningitis (BM) is a global public health concern that results in significant morbidity and mortality. Cerebral arterial narrowing contributes to stroke in BM and may be amenable to intervention. However, it is difficult to diagnose in resource-limited settings where the disease is common. Methods: This was a prospective observational study from September 2015 to December 2019 in sub-Saharan Africa. Children 1 month-18 years of age with neutrophilic pleocytosis or a bacterial pathogen identified in the cerebrospinal fluid were enrolled. Transcranial Doppler ultrasound (TCD) of the middle cerebral arteries was performed daily with the aim to identify flow abnormalities consistent with vascular narrowing. Results: Forty-seven patients were analyzed. The majority had Streptococcus pneumoniae (36%) or Neisseria meningitides (36%) meningitis. Admission TCD was normal in 10 (21%). High flow with a normal pulsatility index (PI) was seen in 20 (43%) and high flow with a low PI was identified in 7 (15%). Ten (21%) had low flow. All children with a normal TCD had a good outcome. Patients with a high-risk TCD flow pattern (high flow/low PI or low flow) were more likely to have a poor outcome (82 vs. 38%, p = 0.001). Conclusions: Abnormal TCD flow patterns were common in children with BM and identified those at high risk of poor neurological outcome.

Neuroinvasive Listeria monocytogenes infection triggers accumulation of brain CD8+ tissue-resident memory T cells in a miR-155-dependent fashion

Background

Brain inflammation is a key cause of cognitive decline after central nervous system (CNS) infections. A thorough understanding of immune responses to CNS infection is essential for developing anti-inflammatory interventions that improve outcomes. Tissue-resident memory T cells (T_RM) are non-recirculating memory T cells that provide surveillance of previously infected tissues. However, in addition to protecting the brain against reinfection, brain T_RM can contribute to post-infectious neuroinflammation. We hypothesized that accumulation of CD8⁺T_RM in the brain could be reduced by inhibiting microRNA (miR)-155, a microRNA that influences development of cytotoxic CD8⁺ T lymphocytes during infection.

Methods

C57BL/6J mice were infected by intraperitoneal injection with a lethal inoculum of Listeria monocytogenes (Lm) then treated with antibiotics. Flow cytometry was used to quantify specific populations of brain leukocytes 28–29 days (d) post-infection (p.i.). To test the degree to which miR-155 altered leukocyte influxes into the brain, infected mice were injected with a miR-155 inhibitor or locked nucleic acid (LNA) scramble control 2d, 4d, 6d, and 8d p.i. along with antibiotic treatment. Bacterial loads in spleen and liver and body weights were measured up to 7d p.i. Brain leukocytes were analyzed 14d and 28d p.i. Confirmatory studies were performed in mutated mice lacking miR-155 (miR-155^−/−)

Results

Lm infection significantly increased the numbers of brain CD3⁺CD8⁺ lymphocytes at 28d p.i. These cells were extravascular, and displayed markers characteristic of T_RM, with the predominant phenotype of CD44⁺CD62L^-CD69⁺CX3CR1⁻. Further analysis showed that > 75% of brain T_RM also expressed CD49a, PD-1, Ly6C, CD103, and CD127. Mice injected with miR-155 inhibitor lost less weight through 7d p.i. than did control mice, whereas bacterial loads in brain, liver, and spleen were not different from controls. By 28d p.i., the numbers of brain CD8⁺ T_RM cells were significantly decreased in mice treated with the inhibitor compared with controls. Similarly, miR-155^−/− mice showed significantly reduced numbers of brain CD8⁺T_RM cells by 28d p.i.

Conclusions

Brain CD8⁺ T_RM populations are established during neuroinvasive Lm infection. Accumulation of brain CD8⁺ T_RM cells is reduced by blocking miR-155 and in miR-155^−/− mice, indicating that this molecule has a critical role in development of these specialized cells. Administering anti-miR-155 during infection could provide a novel avenue for reducing post-infectious neuroinflammation.

Acute Bacterial Meningitis: Challenges to Better Antibiotic Therapy

Bacterial meningitis is a medical emergency requiring highly bactericidal antibiotics to achieve cure. Many challenges exist to achieving optimal patient outcome. First, antibiotics must pass the blood brain barrier. Once in the subarachnoid space, achieving bactericidal therapy involves circumventing antibiotic resistance and, more commonly, antibiotic tolerance arising from the slow growth of bacteria in the nutrient poor cerebrospinal fluid. Finally, bactericidal therapy is most often bacteriolytic, and debris from lysis is highly inflammatory. Controlling damage from lytic products may require adjunctive therapy to prevent neuronal death. These challenges are an extreme example of the different requirements for treating infections in different body sites.

High-Dose Ceftriaxone for Bacterial Meningitis and Optimization of Administration Scheme Based on Nomogram

High dosages of ceftriaxone are used to treat central nervous system (CNS) infections. Dosage adaptation according to the glomerular filtration rate is currently not recommended. Ceftriaxone pharmacokinetics (PK) was investigated by a population approach in patients enrolled in a French multicenter prospective cohort study who received high-dose ceftriaxone for CNS infection as recommended by French guidelines (75 to 100 mg/kg of body weight/day without an upper limit). Only those with suspected bacterial meningitis were included in the PK analysis. A population model was developed using Pmetrics. Based on this model, a dosing nomogram was developed, using the estimated glomerular filtration rate (eGFR) and total body weight as covariates to determine the optimal dosage allowing achievement of targeted plasma trough concentrations. Efficacy and toxicity endpoints were based on previous reports, as follows: total plasma ceftriaxone concentrations of ≥20 mg/liter in >90% of patients for efficacy and ≤100 mg/liter in >90% of patients for toxicity. Based on 153 included patients, a two-compartment model including eGFR and total body weight as covariates was developed. The median value of the unbound fraction was 7.57%, and the median value of the cerebral spinal fluid (CSF)/plasma ratio was 14.39%. A nomogram was developed according to a twice-daily regimen. High-dose ceftriaxone administration schemes, used to treat meningitis, should be adapted to the eGFR and weight, especially to avoid underdosing using current guidelines. (This study has been registered at ClinicalTrials.gov under identifier NCT01745679.).

Epidemiology of lumbar punctures in hospitalized patients in the United States

Objectives

Lumbar puncture (LP) is an important technique for assessing and treating neurological symptoms. The objective of this study was to describe the characteristics of diagnostic lumbar punctures performed on hospitalized patients in the United States.

Methods

We analyzed data from the 2010 National Inpatient Sample (NIS) and the National Emergency Department Survey (NEDS). We included patients treated in the Emergency Department (ED) as well as those admitted to an inpatient bed through the ED. We identified patients undergoing LPs from ICD-9 procedural code 03.31 and CPT code 62270. We generated nationally weighted estimates of the total number of LPs. We also assessed patient and hospital characteristics of cases undergoing LP.

Results

Of an estimated 135 million hospitalizations (ED + admission, or ED only), there were an estimated 362,718 LPs (331,248–394,188), including 273,612 (251,850–295,375) among adults and 89,106 (71,870–106,342) among children (<18 years old). Of the 362,718 LPs, 136,764 (122,117–151,410) were performed in the ED without admission. The most common conditions associated with LP among children were fever of unknown origin, meningitis, seizures and other perinatal conditions. The most common conditions associated with LP among adults were headache and meningitis.

Conclusions

Lumbar Puncture remains an important procedure for diagnostic and therapeutic uses in United States Hospitals.

Differential influences of complement on neutrophil responses to Neisseria meningitidis infection

The complement system is the primary innate immune determinant protecting against invasive diseases caused by the Gram-negative bacterium Neisseria meningitidis (Nme, meningococcus), as evidenced by the extreme susceptibility of individuals with complement deficiencies. In contrast, the role of phagocytes such as neutrophils is much less well understood, although they are recruited in great numbers to the cerebrospinal fluid during meningococcal meningitis. Here, we consider the interaction of Nme with primary human neutrophils using either purified cells or a whole blood model of infection. We found that neutrophils are capable of non-opsonic uptake and killing of different Nme strains. However, in the presence of immune serum featuring active complement, Nme association is strongly increased, whereas this is not the case in heat-inactivated immune serum. Blockade of complement at the level of C3 using the inhibitor compstatin Cp20 reduces the uptake dramatically. In addition, purified neutrophils did not mount an oxidative burst towards Nme unless complement was added and, vice versa, the oxidative burst was strongly reduced in whole blood upon complement inhibition. In contrast, there was no significant impact of complement on neutrophil degranulation or IL-8 secretion. Taken together, neutrophils require complement activation in order to mount a full response towards Nme.

A Review of Meningococcal Disease and Vaccination Recommendations for Travelers

International travel has been steadily increasing since the middle of the twentieth century, including travel to regions with high levels of endemic meningococcal disease and areas with sporadic or sustained meningococcal outbreaks. Although invasive meningococcal disease (IMD) is relatively rare in travelers since the advent of quadrivalent meningococcal vaccines, it remains a serious concern because of its rapid progression, poor prognosis and outcomes, associated treatment delays, and the potential to precipitate outbreaks. Moreover, fatality occurs in up to 22% of those infected. This review will focus on IMD in travelers, with an emphasis on IMD epidemiology and the geographic regions of potential concern for international travelers. As vaccination is the best approach for preventing IMD among travelers, currently available meningococcal vaccines and corresponding country-specific national meningococcal vaccination recommendations, where available, will be summarized by age and type of vaccine recommended. The use of the quadrivalent meningococcal vaccines, specifically the tetanus toxoid conjugate vaccine (including MenACWY-TT; Nimenrix®), as a protective measure against IMD in travelers will be emphasized.

FUNDING

Pfizer Inc.

Complement C5a Receptor 1 Exacerbates the Pathophysiology of N. meningitidis Sepsis and Is a Potential Target for Disease Treatment

Sepsis caused by Neisseria meningitidis (meningococcus) is a rapidly progressing, life-threatening disease. Because its initial symptoms are rather unspecific, medical attention is often sought too late, i.e., when the systemic inflammatory response is already unleashed. This in turn limits the success of antibiotic treatment. The complement system is generally accepted as the most important innate immune determinant against invasive meningococcal disease since it protects the host through the bactericidal membrane attack complex. However, complement activation concomitantly liberates the C5a peptide, and it remains unclear whether this potent anaphylatoxin contributes to protection and/or drives the rapidly progressing immunopathogenesis associated with meningococcal disease. Here, we dissected the specific contribution of C5a receptor 1 (C5aR1), the canonical receptor for C5a, using a mouse model of meningococcal sepsis. Mice lacking C3 or C5 displayed susceptibility that was enhanced by >1,000-fold or 100-fold, respectively, consistent with the contribution of these components to protection. In clear contrast, C5ar1^−/− mice resisted invasive meningococcal infection and cleared N. meningitidis more rapidly than wild-type (WT) animals. This favorable outcome stemmed from an ameliorated inflammatory cytokine response to N. meningitidis in C5ar1^−/− mice in both in vivo and ex vivo whole-blood infections. In addition, inhibition of C5aR1 signaling without interference with the complement bactericidal activity reduced the inflammatory response also in human whole blood. Enticingly, pharmacologic C5aR1 blockade enhanced mouse survival and lowered meningococcal burden even when the treatment was administered after sepsis induction. Together, our findings demonstrate that C5aR1 drives the pathophysiology associated with meningococcal sepsis and provides a promising target for adjunctive therapy.

The devastating consequences of N. meningitidis sepsis arise due to the rapidly arising and self-propagating inflammatory response that mobilizes antibacterial defenses but also drives the immunopathology associated with meningococcemia. The complement cascade provides innate broad-spectrum protection against infection by directly damaging the envelope of pathogenic microbes through the membrane attack complex and triggers an inflammatory response via the C5a peptide and its receptor C5aR1 aimed at mobilizing cellular effectors of immunity. Here, we consider the potential of separating the bactericidal activities of the complement cascade from its immune activating function to improve outcome of N. meningitidis sepsis. Our findings demonstrate that the specific genetic or pharmacological disruption of C5aR1 rapidly ameliorates disease by suppressing the pathogenic inflammatory response and, surprisingly, allows faster clearance of the bacterial infection. This outcome provides a clear demonstration of the therapeutic benefit of the use of C5aR1-specific inhibitors to improve the outcome of invasive meningococcal disease.

Clinical presentation of invasive disease caused by Neisseria meningitidis serogroup Y in Sweden, 1995 to 2012

Over the period 1995–2012, the incidence of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup Y (NmY) increased significantly in Sweden. This is mainly due to the emergence of a predominant cluster named strain type YI subtype 1, belonging to the ST-23 clonal complex (cc). The aim of this study was to examine the clinical picture of patients with invasive disease caused by NmY and to analyse whether the predominant cluster exhibits certain clinical characteristics that might explain the increased incidence. In this retrospective observational study, the medical records available from patients with IMD caused by Nm serogroup Y in Sweden between 1995 and 2012 were systematically reviewed. Patient characteristics, in-hospital findings and outcome were studied and differences between the dominating cluster and other isolates were analysed. Medical records from 175 of 191 patients were retrieved. The median age was 62 years. The all-cause mortality within 30 days of admission was 9% (15/175) in the whole material; 4% (2/54) in the cohort with strain type YI subtype 1 and 11% (12/121) among patients with other isolates. Thirty-three per cent of the patients were diagnosed with meningitis, 19% with pneumonia, 10% with arthritis and 35% were found to have bacteraemia but no apparent organ manifestation. This survey included cases with an aggressive clinical course as well as cases with a relatively mild clinical presentation. There was a trend towards lower mortality and less-severe disease in the cohort with strain type YI subtype 1 compared with the group with other isolates.

Risk scores for outcome in bacterial meningitis: Systematic review and external validation study

OBJECTIVES

To perform an external validation study of risk scores, identified through a systematic review, predicting outcome in community-acquired bacterial meningitis.

METHODS

MEDLINE and EMBASE were searched for articles published between January 1960 and August 2014. Performance was evaluated in 2108 episodes of adult community-acquired bacterial meningitis from two nationwide prospective cohort studies by the area under the receiver operating characteristic curve (AUC), the calibration curve, calibration slope or Hosmer-Lemeshow test, and the distribution of calculated risks.

FINDINGS

Nine risk scores were identified predicting death, neurological deficit or death, or unfavorable outcome at discharge in bacterial meningitis, pneumococcal meningitis and invasive meningococcal disease. Most studies had shortcomings in design, analyses, and reporting. Evaluation showed AUCs of 0.59 (0.57-0.61) and 0.74 (0.71-0.76) in bacterial meningitis, 0.67 (0.64-0.70) in pneumococcal meningitis, and 0.81 (0.73-0.90), 0.82 (0.74-0.91), 0.84 (0.75-0.93), 0.84 (0.76-0.93), 0.85 (0.75-0.95), and 0.90 (0.83-0.98) in meningococcal meningitis. Calibration curves showed adequate agreement between predicted and observed outcomes for four scores, but statistical tests indicated poor calibration of all risk scores.

INTERPRETATION

One score could be recommended for the interpretation and design of bacterial meningitis studies. None of the existing scores performed well enough to recommend routine use in individual patient management.

Time to antibiotic therapy and outcome in bacterial meningitis: a Danish population-based cohort study

BACKGROUND

Community-acquired bacterial meningitis (CABM) is a life-threatening disease and timing of antibiotic therapy remains crucial. We aimed to analyse the impact of antibiotic timing on the outcome of CABM in a contemporary cohort.

METHODS

We conducted a population-based cohort study based on chart reviews of all adult cases (>16 years of age) of CABM in North Denmark from 1998 to 2014 excluding patients given pre-hospital parenteral antibiotics. We used modified Poisson regression analyses to compute the adjusted risk ratio (adj. RR) with 95 % confidence intervals (CIs) for in-hospital mortality and unfavourable outcome at discharge by time after arrival to hospital to adequate antibiotic therapy.

RESULTS

We identified 195 adults with CABM of whom 173 patients were eligible for further analyses. The median door-to-antibiotic time was 2.0 h (interquartile range (IQR) 1.0-5.5). We observed increased adjusted risk ratios for in-hospital mortality of 1.6 (95 % CI 0.8-3.2) and an unfavourable outcome at discharge of 1.5 (95 % CI 1.0-2.2, p = 0.03) when treatment delays exceeded 6 h versus treatment within 2 h of admission. These findings corresponded to adjusted risk ratios of in-hospital mortality of 1.1 per hour of delay (95 % CI 0.8-1.5) and an unfavourable outcome at discharge of 1.1 per hour of delay (95 % CI 1.0-1.3) within the first 6 h of admission. Some patients (31 %) were diagnosed after admission and had more delays in antibiotic therapy and correspondingly increased in-hospital mortality (30 vs 14 %, p = 0.01) and unfavourable outcome (62 vs 37 %, p = 0.002).

CONCLUSIONS

Delay in antibiotic therapy was associated with unfavourable outcome at discharge.

Challenges of bacterial meningitis case management in low income settings: an experience from Ethiopia

OBJECTIVE

To investigate the current diagnostic and therapeutic strategies used in the care of patients with suspected bacterial meningitis at teaching hospitals in Ethiopia.

METHODS

This was a hospital-based retrospective study conducted at four teaching hospitals in different regions of Ethiopia. Participants were patients aged 14 years and older treated for suspected bacterial meningitis. Presenting complaints, diagnostic strategies used and treatments given were obtained from clinical records.

RESULT

A total of 425 patients were included in the study; 52.7% were men and 83.8% were younger than 50 years. Fever, headache, neck stiffness and impaired consciousness were the most common clinical presentations; 55.5% underwent lumbar puncture. Overall, only 96 (22.6%) patients had cerebrospinal fluid abnormalities compatible with bacterial meningitis. A causative bacterium was identified in only 14 cases. Ceftriaxone was used as the empiric treatment of choice, either alone or in combination with other antibiotics; 17.6% of patients were also given vancomycin. Adjunctive dexamethasone was given to 50.4%.

CONCLUSION

Most patients treated as bacterial meningitis did not receive a proper diagnostic workup. The choice of antibiotic was not tailored to the specific clinical condition of the patient. Such an approach may result in poor treatment outcomes and lead to antibiotic resistance. Management of patients with suspected bacterial meningitis should be supported by analysis of cerebrospinal fluid, and treatment should be tailored to local evidence and current evidence-based recommendations.

Hepatocyte growth factor in cerebrospinal fluid differentiates community-acquired or nosocomial septic meningitis from other causes of pleocytosis

Background

Due to anatomical restrictions, the inflammatory response to intracerebral bacterial infections exposes swollen brain tissues to pressure and ischemia, resulting in life-threatening damage. Rapid diagnosis and immediate empirical antibiotic therapy is highly important. However, diagnosing meningitis in patients after neurosurgery is complicated, due to brain tissue damage and changes in cerebrospinal fluid (CSF) caused by surgery. Hepatocyte growth factor (HGF) is a local, acute-phase protein with healing properties. Previous studies on community-acquired septic meningitis reported high levels of intrathecally produced HGF. The present study focused on nosocomial meningitis in assessing the levels of HGF in the CSF.

Methods

HGF concentrations (ELISA) and HGF binding to receptors; c-Met receptor and heparan sulfate proteoglycan were determined in CSF samples (surface plasmon resonance). CSF samples from patients with community-acquired or nosocomial meningitis (217 samples from 135 patients) were compared to those from controls without signs of cerebral nervous system involvement (N = 36) and patients with Alzheimer’s disease (N = 20).

Results

Compared to samples from patients that had undergone neurosurgery and had other infectious diseases, CSF samples from patients with nosocomial meningitis had significantly higher HGF concentrations (p < 0.001) and binding affinity to c-Met (p < 0.001) and HSPG (p = 0.043) receptors. The sensitivity and specificity to identify nosocomial septic meningitis were 69.7 and 93.4 %, respectively. The HGF concentration and binding affinity to HGF receptors were significantly higher in CSF from patients with community-acquired septic meningitis compared to patients with aseptic (viral and subacute) meningitis as well as controls (p < 0.001). The sensitivity and specificity to identify community-acquired septic meningitis were 95.4 and 95.7 %, respectively.

Discussion

In febrile nosocomial infections that occurred post neurosurgery, HGF assessment could substantially improve the differentiation of meningitis from other infections and therefore might be a tool for rapid diagnosis, limiting injuries and guiding antibiotic therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12987-015-0020-z) contains supplementary material, which is available to authorized users.

Bacterial meningitis: insights into pathogenesis and evaluation of new treatment options: a perspective from experimental studies

Bacterial meningitis is associated with high mortality and morbidity rates. Bacterial components induce an overshooting inflammatory reaction, eventually leading to brain damage. Pathological correlates of neurofunctional deficits include cortical necrosis, damage of the inner ear and hippocampal apoptosis. The hippocampal dentate gyrus is important for memory acquisition and harbors a neuronal stem cell niche, thus being potentially well equipped for regeneration. Adjuvant therapies aimed at decreasing the inflammatory reaction, for example, dexamethasone, and those protecting the brain from injury have been evaluated in animal models of the disease. They include nonbacteriolytic antibiotics (e.g., daptomycin), metalloproteinase inhibitors and modulators of the immunological response, for example, granulocyte colony-stimulating factor. Increasing research interest has recently been focused on interventions aimed at supporting regenerative processes.

[Acute care of patients with bacterial meningitis]

BACKGROUND

Bacterial meningitis is a life-threatening emergency that is still associated with high mortality and poor outcome.

OBJECTIVE

The purpose of this article is to provide a review of clinical presentation, diagnostic procedure, therapy, and prognosis in bacterial meningitis. Prognostic factors which could be influenced positively are identified and a focused procedure in the emergency setting and for the treatment of complications are provided.

MATERIAL AND METHODS

This work is based on a literature search (PubMed, guidelines) and personal experience (standard operating procedures, SOP).

RESULTS

Despite improved health care, bacterial meningitis is still associated with high mortality and poor neurological outcome, which has remained largely unaltered during recent decades. Diagnosis and, more importantly, effective therapy of bacterial meningitis are often delayed, having an immediate negative influence on clinical outcome. Neurological and nonneurological complications often necessitate intensive care and may occur rapidly or in the further course of the disease.

CONCLUSION

Immediate initiation of effective therapy is crucial to positively influence mortality and neurological outcome. Antibiotics should be administered within 30 min after admission. To achieve this, a focused and well-organized procedure in the emergency setting is necessary. Because of intra- and extracranial complications, patients need to be treated on intensive care units including neurological expertise and interdisciplinary support.

Impact of 10-valent pneumococcal conjugate vaccine on pneumococcal meningitis in children up to two years of age in Brazil

The objective of this study was to analyze the impact of vaccination against Streptococcus pneumoniae on the morbidity and mortality from pneumococcal meningitis in children ≤ 2 years in Brazil, from 2007 to 2012. This is a descriptive study and ecological analysis using data from the Information System on Notifiable Diseases. Pre-vaccination (2007-2009) and post-vaccination (2011-2012) periods were defined to compare incidence rates and mortality. A total of 1,311 cases and 430 deaths were reported during the study period. Incidence decreased from 3.70/100,000 in 2007 to 1.84/100,000 in 2012, and mortality decreased from 1.30/100,000 to 0.40/100,000, or 50% and 69% respectively, with the greatest impact in the 6-11 month age group. This decrease in Pneumococcal meningitis morbidity and mortality rates two years after introduction of the 10-valent pneumococcal conjugate vaccine suggests its effectiveness.

Neonatal purulent meningitis in southern Tunisia: Epidemiology, bacteriology, risk factors and prognosis

OBJECTIVES

To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM).

METHODOLOGY

Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis >30 cells/mm(3), protein level >1.3 g/l and glucose level <2.2 mmol/l or CSF/blood glucose ratio <0.4.

RESULTS

The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%.

CONCLUSION

This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.

Epidemiology of bacterial meningitis in the USA from 1997 to 2010: a population-based observational study

BACKGROUND

Bacterial meningitis continues to be a substantial cause of morbidity and mortality, but the epidemiological trends after adjunctive dexamethasone recommendations are unknown in the USA. We aimed to describe the changing patterns among the most common bacterial causes in the USA after conjugate vaccination and to assess the association between adjunctive dexamethasone and mortality.

METHODS

For this population-based observational study, we searched information available from hospital discharges about incidence and inpatient mortality for the most important causes of community and nosocomial bacterial meningitis based on International Classification of Diseases coding across all hospitals in the USA between 1997 and 2010 with the HealthCare Cost Utilization Project (HCUP) network database. We calculated incidences according to US Census Bureau data and used a negative binomial regression model to evaluate the significance of changes over time. We assessed mortality from pneumococcus for three periods 1997-2001 (baseline), 2002-04 (transition years), and 2005-08 (after corticosteroid recommendations were available).

FINDINGS

Streptococcus pneumoniae incidence fell from 0·8 per 100 000 people in 1997, to 0·3 per 100 000 people by the end of 2010 (RR 0·3737, 95% CI 0·1825-0·7656). Mortality from pneumococcal meningitis decreased between 2005 (0·049 per 100 000 people) and 2008 (0·024 per 100 000 people) compared with between 2002 (0·073 per 100 000 people) and 2004 (0·063 per 100 000 people; RR 0·5720, 95% CI 0·4303-0·7582). The incidence of Neisseria meningitidis infection decreased from 0·721 per 100 000 people in 1997, to 0·123 per 100 000 people in 2010 (RR 0·1386, 95% CI 0·048-0·4284), which has placed this pathogen close to common bacterial causes of nosocomial meningitis such as staphylococcus and Gram-negative bacteria and to Haemophilus influenzae.

INTERPRETATION

S pneumoniae continues to be the leading identifiable cause of bacterial meningitis in the USA, but with a significant decrease in incidence and mortality associated with the introduction of conjugated vaccines and a mortality decrease that is associated with the introduction of recommendations for use of adjunctive dexamethasone for pneumococcal meningitis.

FUNDING

National Center for Research Resources.

Etiology and antimicrobial resistance patterns of acute bacterial meningitis in children: a 10-year referral hospital-based study in northwest iran

Background:

Bacterial meningitis is still considered as one of the most dangerous infectious diseases, which causes numerous complications and high mortality if not diagnosed and treated timely.

Objectives:

This study was performed to determine antimicrobial resistance patterns of bacterial pathogens isolated from acute bacterial meningitis at Tabriz Children Educational-Health Care Center in Iran.

Patients and Methods:

In a retrospective study (from 2003 through 2013), all patients with bacterial meningitis were identified by cerebrospinal fluids with positive results in culture (107 cases). Patients' necessary data was recorded in a questionnaire. Furthermore, the results of simultaneous blood culture were also examined. Ultimately, antimicrobial susceptibility of isolates was determined using the disc diffusion method.

Results:

One hundred and seven patients with bacterial meningitis were identified by cerebrospinal fluids with positive results in culture. All of patients (100%) had fever (male/female = 1.27/1). The most prevalent pathogens isolated from CSF culture were Streptococcus pneumoniae (34.5%), Haemophilus influenzae type b (23.36%), Neisseria meningitidis (6.54%), Serratia spp. (6.54%), and Klebsiella pneumoniae (5.6%), respectively. Moreover, the patients' blood culture had positive results in 36.44% of cases with H. influenzae type b (20.65%) and S. pneumoniae (6.54%) as the main bacteria isolated from blood. Meningitis occurred mostly in children under two years (P = 0.001). According to antimicrobial susceptibility test, a relatively high resistance was reported against some conventional cephalosporins and other antibiotics.

Conclusions:

S. pneumoniae and H. influenzae type b were the main pathogens of bacterial meningitis in children in the area under study. Most species had relatively high resistance to conventional antibiotics as compared to the past.

Dexamethasone treatment and prognostic factors in community-acquired bacterial meningitis: a Danish retrospective population-based cohort study

INTRODUCTION

The morbidity and mortality in community-acquired bacterial meningitis (CABM) remain substantial and treatment outcomes and predictors of a poor prognosis must be assessed regularly. We aimed to describe the outcome of patients with CABM treated with dexamethasone and to assess the performance of the Dutch Meningitis Risk Score (DMRS).

METHODS

We retrospectively evaluated all adults with CABM in North Denmark Region, 1998-2012. Outcomes included in-hospital mortality and Glasgow Outcome Scale (GOS) score. A GOS score of 5 was categorized as a favourable outcome and scores of 1-4 as unfavourable. We used logistic analysis to compute relative risks (RRs) with 95% confidence intervals (CIs) for an unfavourable outcome adjusted for age, sex, and comorbidity.

RESULTS

We identified a total of 172 cases of CABM. In-hospital mortality was unaffected by the implementation of dexamethasone in 2003 (19% vs 20%). Dexamethasone treatment was associated with a prompt diagnosis of meningitis and a statistically insignificant decrease in the risk of an unfavourable outcome (33% vs 53%; adjusted RR 0.64, 95% CI 0.41-1.01) and in-hospital mortality (15% vs 24%; adjusted RR 0.72, 95% CI 0.35-1.48). Of the risk factors included in the DMRS, we found age and tachycardia to be significantly associated with an unfavourable outcome in the multivariate analyses.

CONCLUSIONS

Patients treated with dexamethasone were more likely to have a favourable outcome, although statistical significance was not reached. Several parameters included in the Dutch risk score were also negative predictors in our cohort, although the entire risk score could not be validated due to a lack of data.

Modulation of hippocampal neuroplasticity by Fas/CD95 regulatory protein 2 (Faim2) in the course of bacterial meningitis

Supplemental digital content is available in the text.

Fas-apoptotic inhibitory molecule 2 (Faim2) is a neuron-specific membrane protein and a member of the evolutionary conserved lifeguard apoptosis regulatory gene family. Its neuroprotective effect in acute neurological diseases has been demonstrated in an in vivo model of focal cerebral ischemia. Here we show that Faim2 is physiologically expressed in the human brain with a changing pattern in cases of infectious meningoencephalitis.In Faim2-deficient mice, there was increased caspase-associated hippocampal apoptotic cell death and an increased extracellular signal-regulated kinase pattern during acute bacterial meningitis induced by subarachnoid infection with Streptococcus pneumoniae type 3 strain. However, after rescuing the animals by antibiotic treatment, Faim2 deficiency led to increased hippocampal neurogenesis at 7 weeks after infection. This was associated with improved performance of Faim2-deficient mice compared to wild-type littermates in the Morris water maze, a paradigm for hippocampal spatial learning and memory. Thus, Faim2 deficiency aggravated degenerative processes in the acute phase but induced regenerative processes in the repair phase of a mouse model of pneumococcal meningitis. Hence, time-dependent modulation of neuroplasticity by Faim2 may offer a new therapeutic approach for reducing hippocampal neuronal cell death and improving cognitive deficits after bacterial meningitis.

Interleukin-18 deficiency and its long-term behavioural and cognitive impacts in a murine model of pneumococcal meningitis

Pneumococcal meningitis often results in death or neurological sequelae, but the underlying pathogenetic mechanisms remain poorly understood. In C57BL/6J mice subjected to intracerebroventricular (icv) challenge with Streptococcus pneumoniae, the chemokine CCL2 and cytokines interferon-γ, interleukin (IL)-1β, IL-6 and tumour necrosis factor were prominently expressed in the brain during the acute phase of the disease. The upregulation of these immune mediators was markedly diminished in IL-18-deficient mice. Uninfected IL-18(-/-) mice exhibited decreases in anxiety phenotype and licking behaviour, and an increase in behavioural habituation, in an automated monitoring system (the IntelliCage). Without antibiotic intervention, a majority of IL-18(+/+) mice developed irreversible disease after icv S. pneumoniae but this was significantly improved by deleting IL-18 gene function. IL-18(+/+) mice cured of pneumococcal meningitis with four doses of ceftriaxone, initiated at 20 h post-inoculation, showed enduring sequelae. These included abnormal behavioural phenotypes featuring diurnal hypoactivity and nocturnal hyperactivity, light phobia and disrupted cognitive function. While the hyperactive phenotype was absent in the corresponding IL-18(-/-) survivors, cognitive impairments and behavioural deficits were still present. Overall, the results suggest that the high levels of cytokines and/or chemokines released after pneumococcal challenge provoked a series of pathological events, ultimately causing acute death. Furthermore, since only a subset of behavioural phenotypes were ameliorated in the pneumococcus-infected IL-18(-/-) mice, the pathological pathways causing mortality may be, at least in part, distinct from those leading to long-term neurological sequelae.

Current concepts in the treatment of bacterial meningitis beyond the neonatal period

The epidemiology and treatment approach to bacterial meningitis has changed dramatically since the advent of antimicrobial therapy. New vaccines against meningeal pathogens have been implemented into national immunization programs successfully around the world. Antibiotic resistance has had a considerable impact on the efficacy of several therapeutic agents. In this review, the authors will discuss the principles of antibiotic chemotherapy, focusing on new agents for the treatment of penicillin-resistant pneumococci and adjunctive treatments to reduce the inflammatory response to bacterial infection of the meninges.

Spontaneous gram-negative bacillary meningitis in adult patients: characteristics and outcome

BACKGROUND

Spontaneous meningitis caused by gram-negative bacilli in adult patients is uncommon and poorly characterized. Our objective is to describe and compare the characteristics and the outcome of adult patients with spontaneous gram-negative bacilli meningitis (GNBM) and spontaneous meningitis due to other pathogens.

METHODS

Prospective single hospital-based observational cohort study conducted between 1982 and 2006 in a university tertiary hospital in Barcelona (Spain). The Main Outcome Measure: In-hospital mortality.

RESULTS

Gram-negative bacilli meningitis was diagnosed in 40 (7%) of 544 episodes of spontaneous acute bacterial meningitis. The most common pathogens were Escherichia coli and Pseudomonas species. On admission, characteristics associated with spontaneous gram-negative bacilli meningitis by multivariate modeling were advanced age, history of cancer, nosocomial acquisition of infection, urinary tract infection as distant focus of infection, absence of rash, hypotension, and a high cerebrospinal fluid white-cell count. Nine (23%) episodes were acquired in the hospital and they were most commonly caused by Pseudomonas. The in-hospital mortality rate was 53%. The mortality rate was higher among patients with Gram-negative bacillary meningitis than among those with other bacterial meningitis and their risk of death was twenty times higher than among patients infected with Neisseria meningitidis (odds ratio 20.47; 95% confidence interval 4.03-103.93; p<0.001).

CONCLUSIONS

Gram-negative bacilli cause 9% of spontaneous bacterial meningitis of known etiology in adults. Characteristics associated with GNBM include advanced age, history of cancer, nosocomial acquisition, and urinary tract infection as distant focus of infection. The mortality rate is higher among patients with gram-negative bacillary meningitis than among those with other bacterial meningitides.

High mortality amongst adolescents and adults with bacterial meningitis in sub-Saharan Africa: an analysis of 715 cases from Malawi

Mortality from bacterial meningitis in African adults is significantly higher than those in better resourced settings and adjunctive therapeutic interventions such as dexamethasone and glycerol have been shown to be ineffective. We conducted a study analysing data from clinical trials of bacterial meningitis in Blantyre, Malawi to investigate the clinical parameters associated with this high mortality.

Methods

We searched for all clinical trials undertaken in Blantyre investigating bacterial meningitis from 1990 to the current time and combined the data from all included trial datasets into one database. We used logistic regression to relate individual clinical parameters to mortality. Adults with community acquired bacterial meningitis were included if the CSF culture isolate was consistent with meningitis or if the CSF white cell count was >100 cells/mm³ (>50% neutrophils) in HIV negative participants and >5 cells/mm³ in HIV positive participants. Outcome was measured by mortality at discharge from hospital (after 10 days of antibiotic therapy) and community follow up (day 40).

Results

Seven hundred and fifteen episodes of bacterial meningitis were evaluated. The mortality rate was 45% at day 10 and 54% at day 40. The most common pathogens were S.pneumoniae (84% of positive CSF isolates) and N.meningitidis (4%). 607/694 (87%) participants tested were HIV antibody positive. Treatment delays within the hospital system were marked. The median presenting GCS was 12/15, 17% had GCS<8 and 44.9% had a seizure during the illness. Coma, seizures, tachycardia and anaemia were all significantly associated with mortality on multivariate analysis. HIV status and pneumococcal culture positivity in the CSF were not associated with mortality. Adults with community acquired bacterial meningitis in Malawi present with a severe clinical phenotype. Predictors of high mortality are different to those seen in Western settings. Optimising in-hospital care and minimising treatment delays presents an opportunity to improve outcomes considerably.

[Bacterial meningitis: factors related to the delay before appropriate antibiotic administration in the emergency department]

OBJECTIVES

We had for aim to check the appropriateness of our practices according to French guidelines (17th consensus conference, SPILF 2008) and to identify variables associated with the delay before appropriate measures were implemented.

METHODS

Our retrospective observational study (2009-2011) focused on acute bacterial meningitis (ABM) in adults. Data was collected on a standardized questionnaire from medical charts and nurse reports.

RESULTS

We included 31 adults presenting with ABM; 29 (93.5%) received ceftriaxone or cefotaxime in the emergency department. Indications for corticosteroids and brain imaging complied with guidelines in respectively 71.0% and 83.9% of cases. The median delays (IQR) were: admission/lumbar puncture (LP), 2h43 [1h09-5h57]; admission/antimicrobials, 3h21 [1h34-5h11]. The indication of suspected ABM in the admission letter was associated with earlier LP (P=0.01), and was almost significantly associated also with faster initiation of adequate antibiotic therapy (P=0.05).

CONCLUSIONS

Suspicion of ABM mentioned in the admission letter was associated to a better management in the emergency department.

Assessing pneumococcal meningitis association with viral respiratory infections and antibiotics: insights from statistical and mathematical models

Pneumococcus is an important human pathogen, highly antibiotic resistant and a major cause of bacterial meningitis worldwide. Better prevention requires understanding the drivers of pneumococcal infection incidence and antibiotic susceptibility. Although respiratory viruses (including influenza) have been suggested to influence pneumococcal infections, the underlying mechanisms are still unknown, and viruses are rarely considered when studying pneumococcus epidemiology. Here, we propose a novel mathematical model to examine hypothetical relationships between Streptococcus pneumoniae meningitis incidence (SPMI), acute viral respiratory infections (AVRIs) and antibiotic exposure. French time series of SPMI, AVRI and penicillin consumption over 2001-2004 are analysed and used to assess four distinct virus-bacteria interaction submodels, ascribing the interaction on pneumococcus transmissibility and/or pathogenicity. The statistical analysis reveals strong associations between time series: SPMI increases shortly after AVRI incidence and decreases overall as the antibiotic-prescription rate rises. Model simulations require a combined impact of AVRI on both pneumococcal transmissibility (up to 1.3-fold increase at the population level) and pathogenicity (up to threefold increase) to reproduce the data accurately, along with diminished epidemic fitness of resistant pneumococcal strains causing meningitis (0.97 (0.96-0.97)). Overall, our findings suggest that AVRI and antibiotics strongly influence SPMI trends. Consequently, vaccination protecting against respiratory virus could have unexpected benefits to limit invasive pneumococcal infections.

Frontline antibiotic therapy

The need to use front-line antibiotics wisely has never been greater. Antibiotic resistance and multi-drug resistant infection, driven by antibiotic use, remain major public health and professional concerns. To overcome these infection problems, use of older antibiotics active against multi drug-resistant pathogens is increasing - for example, colistin, fosfomycin, pivmecillinam, pristinamycin, temocillin and oral tetracyclines. The number of new antibacterials reaching clinical practice has reduced significantly in the last 20 years, most being focused on therapy of Gram-positive infection - eg linezolid, daptomycin, telavancin and ceftaroline. Recent guidance on antibiotic stewardship in NHS trusts in England is likely to provide a backdrop to antibiotic use in hospitals in the next 5 years.

An unusual presentation of meningococcal meningitis--timely recognition can save lives!

Meningococcal meningitis has been known to have a high fatality rate. A high degree of suspicion is required for early recognition and timely intervention. In this report, a case of a young male is presented who came to the emergency department with predominately lower gastrointestinal symptoms but was diagnosed with meningococcal meningitis and managed accordingly.

[Hospital costs related to streptococcal meningitis among children in São José dos Campos, São Paulo State, Brazil]

Knowledge of hospital costs is highly important for public health decision-making. This study aimed to estimate direct hospital costs related to pneumococcal meningitis in children 13 years or younger in the city of São José dos Campos, São Paulo State, Brazil, from January 1999 to December 2008. Data were obtained from medical records. Hospital costs were calculated according to the mixed method for measurement of quantities of items with identified costs and value attribution to items consumed (micro-costing and gross-costing). All costs were calculated according to monetary values for November 2009 and in Brazilian currency (Real). Epi Info 3.5.1 was used for frequencies and means analysis. Forty-one cases were reported. Direct hospital costs varied from R$ 1,277.90 to R$ 19,887.56 (mean = R$ 5,666.43), or 10 to 20 times the mean cost of hospitalization for other diseases. Hospital staff labor was the highest cost, followed by medication, procedures, supplies, and lab tests.

Meningococcal disease: clinical presentation and sequelae

The clinical spectrum of invasive meningococcal disease is diverse with meningitis and/or septicaemia being the commonest modes of presentation. The severity of manifestations of meningococcal infection ranges from bacteraemia, associated with mild non-specific symptoms, to fulminant sepsis with multiorgan failure and death in approximately 10-15% of cases. Localised infections (such as conjunctivitis or septic arthritis) as well as chronic disease may be the sole clinical manifestations but can also lead to disseminated fulminant disease. Among survivors, disabling long-term sequelae can complicate meningococcal disease and result in potentially devastating effects on the quality of life of survivors, most of whom are infants, children and adolescents. The only rational approach to the prevention of meningococcal disease and the associated human suffering is through vaccination.