Community-acquired bacterial meningitis in adults: categorization of causes and timing of death

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.

Cytokine profile in patients with acute bacterial meningitis

BACKGROUND

Bacterial meningitis is a life-threatening disease with high mortality and common long-term sequelae. The inflammatory response in the subarachnoid space, modulated by different cytokines, plays a major role in the pathogenesis of acute central nervous system infections. We aimed to examine correlations of interleukin (IL)-6, IL-8, IL-10, IL-12(p40), and tumor necrosis factor (TNF)-α levels with disease severity, complications, and outcome in patients with acute bacterial meningitis.

METHODS

The study involved 30 patients with bacterial meningitis/meningoencephalitis admitted to the University Hospital St. George, Plovdiv over a period of 4 years. Patients were selected based on clinical presentation and laboratory abnormalities, consistent with a neuroinfection. Enzyme-linked immunosorbent assay was used to measure the studied cytokines in both cerebrospinal fluid (CSF) and serum in parallel. For microbiological diagnosis multiplex, polymerase chain reaction, and CSF culture were used.

RESULTS

In patients with acute bacterial meningitis CSF levels of IL-6, IL-8, IL-10, and TNF-α are significantly increased than in serum. CSF TNF-α, CSF IL-8, and CSF IL-10 had a moderate negative correlation to CSF glucose. It was found that serum IL-8 is significantly elevated in patients who experienced neurological complications, have severe clinical course, and in deceased patients. CSF IL-10 is increased only in patients with severe acute bacterial meningitis.

CONCLUSION

Among patients with acute bacterial meningitis serum IL-8 could delineate these with increased risk of neurological complications, severe clinical course, and fatal outcome. Serum IL-8 and CSF IL-10 could be used as indicators of disease severity.

A comparative study between children and adults with bacterial neuroinfections

Abstract.

Longer than 2 hours to antibiotics is associated with doubling of mortality in a multinational community-acquired bacterial meningitis cohort

To optimally define the association between time to effective antibiotic therapy and clinical outcomes in adult community-acquired bacterial meningitis. A systematic review of the literature describing the association between time to antibiotics and death or neurological impairment due to adult community-acquired bacterial meningitis was performed. A retrospective cohort, multivariable and propensity-score based analyses were performed using individual patient clinical data from Australian, Danish and United Kingdom studies. Heterogeneity of published observational study designs precluded meta-analysis of aggregate data (I² = 90.1%, 95% CI 71.9–98.3%). Individual patient data on 659 subjects were made available for analysis. Multivariable analysis was performed on 180–362 propensity-score matched data. The risk of death (adjusted odds ratio, aOR) associated with treatment after two hours was 2.29 (95% CI 1.28–4.09) and increased substantially thereafter. Similarly, time to antibiotics of greater than three hours was associated with an increase in the occurrence of neurological impairment (aOR 1.79, 95% CI 1.03–3.14). Among patients with community-acquired bacterial meningitis, odds of mortality increase markedly when antibiotics are given later than two hours after presentation to the hospital.

Outcomes and Health Care Resource Utilization of Adult Bacterial Meningitis in the United States

OBJECTIVE

To examine the longitudinal health care resource utilization, in-hospital mortality, and incidence of downstream complications of bacterial meningitis in the United States.

METHODS

Using IBM MarketScan, we retrieved data on adult patients with a diagnosis of bacterial meningitis admitted to a US hospital between 2008 and 2015. Patients were stratified into groups (1) with/without prior head trauma/neurosurgical complications, (2) nosocomial/community acquisition, and (3) Gram-negative/positive bacteria. Cost data were collected for up to 2 years and analyzed with descriptive statistics and longitudinal modeling.

RESULTS

Among 4,496 patients with bacterial meningitis, 16.5% and 4.6% had preceding neurosurgical complications and head injuries, respectively. Lumbar punctures were performed in 37.3% of patients without prior trauma/complications who went on to develop nosocomial meningitis, and those with prior head injuries or complications had longer initial hospital stays (17.0 days vs 8.0 days). Within a month of diagnosis, 29.2% of patients with bacterial meningitis had experienced downstream complications, most commonly hydrocephalus (12.7%). The worst 30-day mortality was due to tuberculous (12.3%) and streptococcal meningitis (7.2%). Overall, prior head trauma and complications were associated with higher costs. Community-acquired bacterial meningitis had lower median baseline costs relative to the nosocomial group (no head trauma/complication: $17,152 vs $82,778; head trauma/complication: $92,428 vs $168,309) but higher median costs within 3 months of diagnosis (no head trauma/complication: $47,911 vs $34,202; head trauma/complication: $89,207 vs $58,947). All costs demonstrated a sharp decline thereafter.

CONCLUSIONS

Bacterial meningitis remains costly and devastating, especially for those who experience traumatic head injuries or have a complicated progress after neurosurgery.

Characteristics and outcome of spontaneous bacterial meningitis in patients with diabetes mellitus

BACKGROUND

Studies on bacterial meningitis in diabetics patients versus non-diabetics are scarce. In patients with diabetes, bacterial meningitis may have a different presentation, etiology and course. We analyzed and compared the characteristics and outcome of spontaneous BM in adult patients with and without diabetes mellitus (DM).

METHODS

We performed a single-center, prospective observational cohort study, conducted between 1982 and 2017, in a tertiary university hospital in Barcelona (Spain). The primary outcome measure was in-hospital mortality.

RESULTS

We evaluated 715 episodes of bacterial meningitis; 106 patients (15%) had diabetes mellitus. Patients with diabetes were older (median 67 [IQR 17] vs 49 [IQR 40] years, p <  0.001) and more often had a Charlson comorbidity score of ≥3 (40% vs 15%, p <  0.001). Neck stiffness (56% vs 75%, p <  0.001), headache (41% vs 78%) p <  0.001), nausea and/or vomiting (32% vs 56% p < 0.001), and rash (12% vs 26%, p = 0.007) were less frequent in diabetics, whereas altered mental status was more common. Streptococcus pneumoniae and Listeria meningitis were the most common etiologic agents (24 and 18%, respectively). Listeria was more frequent (18% vs. 10%, p = 0.033), whereas meningococcal meningitis was less frequent (10% vs 32%, p < 0.001). Overall mortality was higher in patients with diabetes (26% vs 16%, p = 0.025) concerning non-diabetics.

CONCLUSIONS

Patients with bacterial meningitis and diabetes mellitus are older, have more comorbidities, and higher mortality. S. pneumoniae and L. monocytogenes are the predominant pathogens, Listeria being more common, whereas Neisseria meningitidis is significantly less frequent than in non-diabetics.

The cause of death in bacterial meningitis

Background

Death from bacterial meningitis is rarely attributed to the actual event causing death.

The present study therefore categorized and characterized the cause and time of death due to bacterial meningitis.

Methods

In a cohort of patients > 15 years of age with community acquired bacterial meningitis the medical records were reviewed, and a clinical cause of death categorized into six main categories: 1) CNS complications, 2) Systemic complications, 3) Combination of systemic and CNS complications, 4) Sudden death, 5) Withdrawal of care, or 6) Unknown.

Results

We identified 358 patients of which 84 (23%) died in-hospital. Causes of death were ascribed to CNS complications in 43%, Systemic complications in 39%, Combined CNS and systemic complications in 4%, Sudden death in 7% and withdrawal of care in 5%. Brain herniation, circulatory failure, intractable seizures and other brain injury were the most common specific causes of death within 14 days from admission (55%).

Conclusion

Fatal complications due to the primary infection – meningitis - is most common within 14 days of admission. The diversity of complications causing death in meningitis suggest that determining the clinical cause of death is essential to the evaluation of novel treatment strategies.

Bacterial meningitis in Finland, 1995-2014: a population-based observational study

OBJECTIVES

Bacterial meningitis remains an important cause of morbidity and mortality worldwide. Its epidemiological characteristics, however, are changing due to new vaccines and secular trends. Conjugate vaccines against Haemophilus influenzae type b and Streptococcus pneumoniae (10-valent) were introduced in 1986 and 2010 in Finland. We assessed the disease burden and long-term trends of five common causes of bacterial meningitis in a population-based observational study.

METHODS

A case was defined as isolation of S. pneumoniae, Neisseria meningitidis, Streptococcus agalactiae, Listeria monocytogenes or H. influenzae from cerebrospinal fluid and reported to national, population-based laboratory surveillance system during 1995-2014. We evaluated changes in incidence rates (Poisson or negative binomial regression), case fatality proportions (χ²) and age distribution of cases (Wilcoxon rank-sum).

RESULTS

During 1995-2014, S. pneumoniae and N. meningitidis accounted for 78% of the total 1361 reported bacterial meningitis cases. H. influenzae accounted for 4% of cases (92% of isolates were non-type b). During the study period, the overall rate of bacterial meningitis per 1 00 000 person-years decreased from 1.88 cases in 1995 to 0.70 cases in 2014 (4% annual decline (95% CI 3% to 5%). This was primarily due to a 9% annual reduction in rates of N. meningitidis (95% CI 7% to 10%) and 2% decrease in S. pneumoniae (95% CI 1% to 4%). The median age of cases increased from 31 years in 1995-2004 to 43 years in 2005-2014 (p=0.0004). Overall case fatality proportion (10%) did not change from 2004 to 2009 to 2010-2014.

CONCLUSIONS

Substantial decreases in bacterial meningitis were associated with infant conjugate vaccination against pneumococcal meningitis and secular trend in meningococcal meningitis in the absence of vaccination programme. Ongoing epidemiological surveillance is needed to identify trends, evaluate serotype distribution, assess vaccine impact and develop future vaccination strategies.

Characteristics and outcome of spontaneous bacterial meningitis in patients with cancer compared to patients without cancer

In cancer patients, who are frequently immunocompromised, bacterial meningitis (BM) can be a severe complication, with a different presentation, etiology, and course, compared to patients without cancer. Our objective is to compare the characteristics and outcomes of BM in patients with and without cancer. A single-center, prospective observational cohort study, conducted between 1982 and 2012, in a tertiary university hospital in Barcelona (Spain). The main outcome measure is in-hospital mortality. We evaluated 659 episodes of BM; 97 (15%) had active cancer. Patients with malignancies were older (median 63 (interquartile range [IQR] 24) vs 52 [IQR 42] years, P < .001) and more often had a Charlson comorbidity score of ≥3 (51% vs 11%, P < .001). The classic meningitis triad (35% vs 50%, P = .05), fever (91% vs 96%, P = .03), neck stiffness (58% vs 78%, P < .001), headache (63% vs 77%) P = .003), and rash (7% vs 30%, P < .001) were less frequent. There was a longer interval between admission and antibiotic therapy (median 5 [IQR 14] vs 3 [IQR 6] hours, P < .001). Listeria meningitis was the commonest cause of BM (29%) and was more frequent in cancer than noncancer (8%, P < .001) patients, whereas meningococcal meningitis was much less frequent (4% vs 36%, P < .001). Overall mortality was higher in patients with cancer (31% vs 16%, P < .001), although cancer was not associated with an unfavorable outcome in the multivariate analysis (odds ratio 1.825, P = .07). Patients with meningitis and cancer are older and have more subtle clinical manifestations than patients without cancer. Listeria monocytogenes is the predominant pathogen and mortality is higher in cancer patients.

Community-acquired bacterial meningitis

Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma (nosocomial bacterial meningitis). Despite advances in treatment and vaccinations, community-acquired bacterial meningitis remains one of the most important infectious diseases worldwide. Streptococcus pneumoniae and Neisseria meningitidis are the most common causative bacteria and are associated with high mortality and morbidity; vaccines targeting these organisms, which have designs similar to the successful vaccine that targets Haemophilus influenzae type b meningitis, are now being used in many routine vaccination programmes. Experimental and genetic association studies have increased our knowledge about the pathogenesis of bacterial meningitis. Early antibiotic treatment improves the outcome, but the growing emergence of drug resistance as well as shifts in the distribution of serotypes and groups are fuelling further development of new vaccines and treatment strategies. Corticosteroids were found to be beneficial in high-income countries depending on the bacterial species. Further improvements in the outcome are likely to come from dampening the host inflammatory response and implementing preventive measures, especially the development of new vaccines.

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.

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.

Corticosteroids for acute bacterial meningitis

BACKGROUND

In experimental studies, the outcome of bacterial meningitis has been related to the severity of inflammation in the subarachnoid space. Corticosteroids reduce this inflammatory response.

OBJECTIVES

To examine the effect of adjuvant corticosteroid therapy versus placebo on mortality, hearing loss and neurological sequelae in people of all ages with acute bacterial meningitis.

SEARCH METHODS

We searched CENTRAL (2015, Issue 1), MEDLINE (1966 to January week 4, 2015), EMBASE (1974 to February 2015), Web of Science (2010 to February 2015), CINAHL (2010 to February 2015) and LILACS (2010 to February 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of corticosteroids for acute bacterial meningitis.

DATA COLLECTION AND ANALYSIS

We scored RCTs for methodological quality. We collected outcomes and adverse effects. We performed subgroup analyses for children and adults, causative organisms, low-income versus high-income countries, time of steroid administration and study quality.

MAIN RESULTS

We included 25 studies involving 4121 participants (2511 children and 1517 adults; 93 mixed population). Four studies were of high quality with no risk of bias, 14 of medium quality and seven of low quality, indicating a moderate risk of bias for the total analysis. Nine studies were performed in low-income countries and 16 in high-income countries.Corticosteroids were associated with a non-significant reduction in mortality (17.8% versus 19.9%; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.80 to 1.01, P value = 0.07). A similar non-significant reduction in mortality was observed in adults receiving corticosteroids (RR 0.74, 95% CI 0.53 to 1.05, P value = 0.09). Corticosteroids were associated with lower rates of severe hearing loss (RR 0.67, 95% CI 0.51 to 0.88), any hearing loss (RR 0.74, 95% CI 0.63 to 0.87) and neurological sequelae (RR 0.83, 95% CI 0.69 to 1.00).Subgroup analyses for causative organisms showed that corticosteroids reduced mortality in Streptococcus pneumoniae (S. pneumoniae) meningitis (RR 0.84, 95% CI 0.72 to 0.98), but not in Haemophilus influenzae (H. influenzae) orNeisseria meningitidis (N. meningitidis) meningitis. Corticosteroids reduced severe hearing loss in children with H. influenzae meningitis (RR 0.34, 95% CI 0.20 to 0.59) but not in children with meningitis due to non-Haemophilus species.In high-income countries, corticosteroids reduced severe hearing loss (RR 0.51, 95% CI 0.35 to 0.73), any hearing loss (RR 0.58, 95% CI 0.45 to 0.73) and short-term neurological sequelae (RR 0.64, 95% CI 0.48 to 0.85). There was no beneficial effect of corticosteroid therapy in low-income countries.Subgroup analysis for study quality showed no effect of corticosteroids on severe hearing loss in high-quality studies.Corticosteroid treatment was associated with an increase in recurrent fever (RR 1.27, 95% CI 1.09 to 1.47), but not with other adverse events.

AUTHORS' CONCLUSIONS

Corticosteroids significantly reduced hearing loss and neurological sequelae, but did not reduce overall mortality. Data support the use of corticosteroids in patients with bacterial meningitis in high-income countries. We found no beneficial effect in low-income countries.

Sudden neuropathological deaths: An autopsy study

BACKGROUND

Sudden or unexpected death can occur from unnatural causes, such as violence or poisoning, as well as from natural causes. Second to cardiac causes, neuropathology is one of the main causes of sudden natural death. In spite of the increasing incidence of neuropathological deaths, few studies have been conducted in Asia - hence the reason for the present study.

METHODS

A 10-year (January 2003 to December 2012) retrospective study was conducted at the MS medico-legal institute in a metropolitan city of southern India. All the cases of sudden natural death, where the cause of death was opined to be due to a neuropathology after meticulous medico-legal autopsy and chemical analysis, were included.

RESULTS AND CONCLUSIONS

A total of 7520 reported deaths were investigated. These included 291 sudden natural deaths, amongst which the death was attributed to neuropathology in 43 cases (14.7%). Of these 43 cases, 69.7% were male and 30.3% were female. The majority of cases (25.5%) were in those aged ≥60 years. Causes of neuropathology were due to subarachnoid haemorrhage in 48.8% of cases, stroke in 30.2%, meningitis in 14% and tumours in 7%. There was history of hypertension in 46.5% of cases, diabetes in 32.5% of cases and cardiac disease in 18.6% of cases.

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.

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.

Fulminant bacterial meningitis

BACKGROUND

Fulminant bacterial meningitis is a rare host reaction to infection characterized by sudden onset, rapid deterioration, abrupt cerebral edema and refractory intracranial hypertension associated with an extremely high mortality rate.

METHODS

A search of all relevant medical literature since 1900 was conducted to clarify the nature of this entity and its medical management.

RESULTS

Fulminant meningitis occurs in a small percentage of all cases of bacterial meningitis, at all ages and with all infecting organisms. The mortality rate exceeds 50%. Descriptions of fulminant bacterial meningitis are found in medical literature from the preantibiotic era. Its incidence and clinical character have not changed since the introduction of antibiotics and advanced intensive care medicine. The explosive cerebral edema cannot be predicted, and the underlying molecular pathophysiology remains poorly understood. Vigorous neuroresuscitation and the use of adjunctive techniques to control the cerebral edema have not been shown to modify the extreme intracranial hypertension and risk of herniation.

CONCLUSION

Fulminant bacterial meningitis is an example of an aberrant host response to infection that challenges available medical intervention.

Prognostic indicators in bacterial meningitis: a case–control study

This was a case–control study to identify prognostic indicators of bacterial meningitis in a reference hospital in Pernambuco/Brazil. The data were collected from charts of 294 patients with bacterial meningitis between January 2000 and December 2004. Variables were grouped in biological, clinical, laboratory and etiologic agent/treatment. Variables selected in each step were grouped and adjusted for age. Two models were created: one containing clinical variables (clinical model) and other containing laboratory variables (laboratory model). In the clinical model the variables associated with death due to bacterial meningitis were dyspnea (p = 0.006), evidence of shock (p = 0.051), evidence of altered mental state (p = 0.000), absence of headache (p = 0.008), absence of vomiting (p = 0.052), and age ≥40 years old (p = 0.013). In the laboratory model, the variables associated with death due to bacterial meningitis were positive blood cultures (p = 0.073) and thrombocytopenia (p = 0.019). Identification of prognostic indicators soon after admission may allow early specific measures, like admission of patients with higher risk of death to Intensive Care Units.

Hydrocephalus is a rare outcome in community-acquired bacterial meningitis in adults: a retrospective analysis

Background

Community-acquired bacterial meningitis (CABM) continues to have a high mortality rate and often results in severe sequelae among survivors. Lately, an increased effort has been focused on describing the neurological complications of meningitis including hydrocephalus. To aid in this field of research we set out to ascertain the risk and outcome of hydrocephalus in patients with community-acquired bacterial meningitis (CABM) in North Denmark Region.

Methods

We conducted a retrospective population-based cohort study of CABM cases above 14 years of age. Cases diagnosed during a 13-year period, 1998 through 2010, were identified in a laboratory register and data were acquired through patient records. Cases not confirmed by culture met other strict inclusion criteria. The diagnosis of hydrocephalus relied upon the radiologists’ reports on cranial imaging. Outcome was graded according to the Glasgow Outcome Scale at discharge from the primary admission. Long-term sequelae were based upon any subsequent hospital contacts until the end of 2011.

Results

Hydrocephalus was diagnosed in five of 165 episodes (3%) and all were classified as communicating. Only 120 patients had cranial imaging done and in this group the rate was 4.2%. In three cases hydrocephalus was present at admission, while two cases were diagnosed on days 44 and 99, respectively, due to altered mental status. The aetiology was either Eschericia coli (n = 2) or Streptococcus pneumoniae (n = 3). Case fatality was 60% among cases with hydrocephalus and 17% among other cases. Case fatality was similar irrespective of whether patients had a cranial CT or not.

Conclusions

Hydrocephalus was diagnosed in 3% of adolescent and adult cases with CABM and had a high case fatality rate in spite of specialised medical care and neurosurgical interventions. Our findings are comparable with a recent Dutch national prospective study.

Corticosteroids for acute bacterial meningitis

BACKGROUND

In experimental studies, the outcome of bacterial meningitis has been related to the severity of inflammation in the subarachnoid space. Corticosteroids reduce this inflammatory response.

OBJECTIVES

To examine the effect of adjuvant corticosteroid therapy versus placebo on mortality, hearing loss and neurological sequelae in people of all ages with acute bacterial meningitis.

SEARCH METHODS

We searched CENTRAL 2012, Issue 12, MEDLINE (1966 to January week 2, 2013), EMBASE (1974 to January 2013), Web of Science (2010 to January 2013), CINAHL (2010 to January 2013) and LILACS (2010 to January 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of corticosteroids for acute bacterial meningitis.

DATA COLLECTION AND ANALYSIS

We scored RCTs for methodological quality. We collected outcomes and adverse effects. We performed subgroup analyses for children and adults, causative organisms, low-income versus high-income countries, time of steroid administration and study quality.

MAIN RESULTS

Twenty-five studies involving 4121 participants were included. Corticosteroids were associated with a non-significant reduction in mortality (17.8% versus 19.9%; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.80 to 1.01, P = 0.07). A similar non-significant reduction in mortality was observed in adults receiving corticosteroids (RR 0.74, 95% CI 0.53 to 1.05, P = 0.09). Corticosteroids were associated with lower rates of severe hearing loss (RR 0.67, 95% CI 0.51 to 0.88), any hearing loss (RR 0.74, 95% CI 0.63 to 0.87) and neurological sequelae (RR 0.83, 95% CI 0.69 to 1.00).Subgroup analyses for causative organisms showed that corticosteroids reduced mortality in Streptococcus pneumoniae (S. pneumoniae) meningitis (RR 0.84, 95% CI 0.72 to 0.98), but not in Haemophilus influenzae (H. influenzae) orNeisseria meningitidis (N. meningitidis) meningitis. Corticosteroids reduced severe hearing loss in children with H. influenzae meningitis (RR 0.34, 95% CI 0.20 to 0.59) but not in children with meningitis due to non-Haemophilus species.In high-income countries, corticosteroids reduced severe hearing loss (RR 0.51, 95% CI 0.35 to 0.73), any hearing loss (RR 0.58, 95% CI 0.45 to 0.73) and short-term neurological sequelae (RR 0.64, 95% CI 0.48 to 0.85). There was no beneficial effect of corticosteroid therapy in low-income countries.Subgroup analysis for study quality showed no effect of corticosteroids on severe hearing loss in high-quality studies.Corticosteroid treatment was associated with an increase in recurrent fever (RR 1.27, 95% CI 1.09 to 1.47), but not with other adverse events.

AUTHORS' CONCLUSIONS

Corticosteroids significantly reduced hearing loss and neurological sequelae, but did not reduce overall mortality. Data support the use of corticosteroids in patients with bacterial meningitis in high-income countries. We found no beneficial effect in low-income countries.

The spectrum of acute bacterial meningitis in elderly patients

BACKGROUND

We conducted a prospective, observational study in Barcelona to determine the epidemiology, clinical features, and outcome of elderly patients with acute bacterial meningitis (ABM) compared with younger adults.

METHODS

During 1982-2010, all patients with ABM were prospectively evaluated. There were two groups: I (15-64 years) and II (≥ 65 years). All patients underwent clinical examination on admission and at discharge following a predefined protocol.

RESULTS

We evaluated 635 episodes of ABM. The incidence was 4.03/100,000 (Group I) and 7.40 /100,000 inhabitants/year (Group II) (RR = 1.84; 95%CI: 1.56-2.17, P < 0.0001). Elderly patients had co-morbid conditions more frequently (P < 0.0001) and more frequently lacked fever (P = 0.0625), neck stiffness (P < 0.0001) and skin rash (P < 0.0001), but had an altered level of consciousness more often (P < 0.0001). The interval admission-start of antibiotic therapy was longer for elderly patients (P < 0.0001). Meningococcal meningitis was less frequent in elderly patients (P < 0.0001), whereas listerial (P = 0.0196), gram-negative bacillary (P = 0.0065), and meningitis of unknown origin (P = 0.0076) were more frequent. Elderly patients had a higher number of neurologic (P = 0.0009) and extra-neurologic complications (P < 0.0001). The overall mortality ratio was higher in elderly patients (P < 0.0001).

CONCLUSIONS

Elderly people are at higher risk of having ABM than younger adults. ABM in the elderly presents with co-morbid conditions, is clinically subtler, has a longer interval admission-antibiotic therapy, and has non-meningococcal etiology. It is associated with an earlier and higher mortality rate than in younger patients.

The changing pattern of bacterial meningitis in adult patients at a large tertiary university hospital in Barcelona, Spain (1982-2010)

BACKGROUND

We conducted a prospective, observational study in Barcelona (Spain) to determine changes in the spectrum of adult patients with bacterial meningitis (BM) over a 29-year period.

METHODS

The observation was divided into two periods: 1982-1995 (I) and 1996-2010 (II). All patients underwent clinical examination on admission and at discharge following a predefined protocol.

RESULTS

We evaluated 635 episodes of BM. The most frequent etiologic agents were Neisseria meningitidis and Streptococcus pneumoniae in periods I and II, respectively. Patients in period II were older (Median: 47.5 [95%CI: 23.0-64.5] vs. 58.0 [39.0-73.0] years, P<0.0001), had a longer interval from admission to therapy (Median: 2.3 [95%CI: 1.0-5.0] vs. 4.0 [2.0-12.0] hours, P<0.0001), and more frequently had co-morbid conditions (39.1% vs. 62%, P<0.0001). Meningococcal meningitis decreased by 66% (P<0.0001), whereas meningitis by Listeria monocytogenes increased by 110% (P=0.0007) in period II. There were no differences in the overall case-fatality and post-meningitic sequelae rates between both periods.

CONCLUSIONS

BM in adult patients has substantially changed over 29 years in terms of population affected, aetiology, and management, but not in terms of its overall mortality rate and appearance of post-meningitic sequelae.

The use of dexamethasone in bacterial meningitis in children and adults: a retrospective analysis

Bacterial meningitis is a life-threatening illness that results from bacterial infection of the meninges and is associated with high mortality and morbidity rate, especially when the Streptococcus pneumoniae is the causative agent. Dexamethasone as adjunctive therapy to antibiotics does not influence the outcome or the complications in children as well as in adults suffering bacterial meningitis. However, we identified some prognostic parameters in the outcome of bacterial meningitis, and when dexamethasone was given in presence of at least one of 3 poor prognostic CSF parameters (WBC < 1000/mm³, glucose < 20 mg/dl, lactate > 10 mg/dl) it substantially improved the outcome.

Corticosteroids for acute bacterial meningitis

BACKGROUND

In experimental studies, the outcome of bacterial meningitis has been related to the severity of inflammation in the subarachnoid space. Corticosteroids reduce this inflammatory response.

OBJECTIVES

To examine the effect of adjuvant corticosteroid therapy versus placebo on mortality, hearing loss and neurological sequelae in people of all ages with acute bacterial meningitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, issue 1), MEDLINE (1966 to February 2010), EMBASE (1974 to February 2010) and Current Contents (2001 to February 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of corticosteroids for acute bacterial meningitis.

DATA COLLECTION AND ANALYSIS

We scored RCTs for methodological quality. We collected outcomes and adverse effects. We performed subgroup analyses for children and adults, causative organisms, low-income versus high-income countries, time of steroid administration and study quality.

MAIN RESULTS

Twenty-four studies involving 4041 participants were included. Similar numbers of participants died in the corticosteroid and placebo groups (18.0% versus 20.0%; risk ratio (RR) 0.92, 95% confidence interval (CI) 0.82 to 1.04, P = 0.18). There was a trend towards lower mortality in adults receiving corticosteroids (RR 0.74, 95% CI 0.53 to 1.05, P = 0.09). Corticosteroids were associated with lower rates of severe hearing loss (RR 0.67, 95% CI 0.51 to 0.88), any hearing loss (RR 0.76, 95% CI 0.64 to 0.89) and neurological sequelae (RR 0.83, 95% CI 0.69 to 1.00).Subgroup analyses for causative organisms showed that corticosteroids reduced severe hearing loss in Haemophilus influenzae meningitis (RR 0.34, 95% CI 0.20 to 0.59) and reduced mortality in Streptococcus pneumoniae meningitis (RR 0.84, 95% CI 0.72 to 0.98).In high-income countries, corticosteroids reduced severe hearing loss (RR 0.51, 95% CI 0.35 to 0.73), any hearing loss (RR 0.58, 95% CI 0.45 to 0.73) and short-term neurological sequelae (RR 0.64, 95% CI 0.48 to 0.85). There was no beneficial effect of corticosteroid therapy in low-income countries.Subgroup analysis for study quality showed no effect of corticosteroids on severe hearing loss in high quality studies.Corticosteroid treatment was associated with an increase in recurrent fever (RR 1.27, 95% CI 1.09 to 1.47), but not with other adverse events.

AUTHORS' CONCLUSIONS

Corticosteroids significantly reduced hearing loss and neurological sequelae, but did not reduce overall mortality. Data support the use of corticosteroids in patients with bacterial meningitis in high-income countries. We found no beneficial effect in low-income countries.

Community-acquired bacterial meningitis in alcoholic patients

Background

Alcoholism is associated with susceptibility to infectious disease, particularly bacterial pneumonia. In the present study we described characteristics in alcoholic patients with bacterial meningitis and delineate the differences with findings in non-alcoholic adults with bacterial meningitis.

Methods/Principal Findings

This was a prospective nationwide observational cohort study including patients aged >16 years who had bacterial meningitis confirmed by culture of cerebrospinal fluid (696 episodes of bacterial meningitis occurring in 671 patients). Alcoholism was present in 27 of 686 recorded episodes of bacterial meningitis (4%) and alcoholics were more often male than non-alcoholics (82% vs 48%, P = 0.001). A higher proportion of alcoholics had underlying pneumonia (41% vs 11% P<0.001). Alcoholics were more likely to have meningitis due to infection with Streptococcus pneumoniae (70% vs 50%, P = 0.01) and Listeria monocytogenes (19% vs 4%, P = 0.005), whereas Neisseria meningitidis was more common in non-alcoholic patients (39% vs 4%, P = 0.01). A large proportion of alcoholics developed complications during clinical course (82% vs 62%, as compared with non-alcoholics; P = 0.04), often cardiorespiratory failure (52% vs 28%, as compared with non-alcoholics; P = 0.01). Alcoholic patients were at risk for unfavourable outcome (67% vs 33%, as compared with non-alcoholics; P<0.001).

Conclusions/Significance

Alcoholic patients are at high risk for complications resulting in high morbidity and mortality. They are especially at risk for cardiorespiratory failure due to underlying pneumonia, and therefore, aggressive supportive care may be crucial in the treatment of these patients.

[Managing adult patients with acute community-acquired meningitis presumed of bacterial origin]

Early clinical data must lead to suspect bacterial meningitis if fever, the most frequent sign, is present and if it is associated with more or less constant neurological and meningeal signs (consciousness impairment, headache, neck stiffness, focal neurological deficit, seizure, etc.). A skin rash is frequent in case of meningococcal meningitis whereas cranial nerve palsy is more in favor of tuberculous or Listeria meningitis. Presence of otitis, sinusitis, pneumonia, or a recent head trauma strongly suggests a pneumococcal involvement. Tuberculous meningitis is generally characterized by a slow evolution of meningeal signs together with aspecific signs. The main prognostic factors are consciousness impairment, circulatory instability, focal neurological signs, and advanced age. Morbidity and mortality are increased in case of pneumococcal compared to meningococcal meningitis. Cranial tomodensitometry gives further information about intracranial complications of meningitis. In some cases, particularly if focal neurological or intracranial hypertension signs are present, it must be performed before a lumbar puncture. The risk factors of meningitis must be investigated and treated if possible according to the bacterium. The management of patient after hospital discharge depends on evolution after treatment. The presence of neurological sequels imposes a specialized ambulatory follow-up. Neuropsychological sequels (cognitive dysfunction, memory impairment) can also persist for years even in absence of other neurological disorders.

Management of meningitis due to antibiotic-resistant Acinetobacter species

Acinetobacter meningitis is becoming an increasingly common clinical entity, especially in the postneurosurgical setting, with mortality from this infection exceeding 15%. Infectious Diseases Society of America guidelines for therapy of postneurosurgical meningitis recommend either ceftazidime or cefepime as empirical coverage against Gram-negative pathogens. However, assessment of the pharmacodynamics of these cephalosporins in cerebrospinal fluid suggests that recommended doses will achieve pharmacodynamic targets against fewer than 10% of contemporary acinetobacter isolates. Thus, these antibiotics are poor options for suspected acinetobacter meningitis. From in vitro and pharmacodynamic perspectives, intravenous meropenem plus intraventricular administration of an aminoglycoside may represent a superior, albeit imperfect, regimen for suspected acinetobacter meningitis. For cases of meningitis due to carbapenem-resistant acinetobacter, use of tigecycline is not recommended on pharmacodynamic grounds. The greatest clinical experience rests with use of polymyxins, although an intravenous polymyxin alone is inadvisable. Combination with an intraventricularly administered antibiotic plus removal of infected neurosurgical hardware appears the therapeutic strategy most likely to succeed in this situation. Unfortunately, limited development of new antibiotics plus the growing threat of multidrug-resistant acinetobacter is likely to increase the problems posed by acinetobacter meningitis in the future.

Combination of daptomycin plus ceftriaxone is more active than vancomycin plus ceftriaxone in experimental meningitis after addition of dexamethasone

We examined the cerebrospinal fluid penetration of daptomycin after the addition of dexamethasone and its bactericidal efficacy with and without ceftriaxone in an experimental rabbit model of pneumococcal meningitis. The combination of daptomycin with ceftriaxone was the most efficacious regimen for pneumococcal meningitis. The previous addition of dexamethasone affected the antibacterial activity of daptomycin only marginally, either as monotherapy or combined with ceftriaxone, although the penetration of daptomycin into inflamed meninges was significantly reduced from 6 to 2%. Daptomycin with ceftriaxone might be a potential candidate for the empirical therapy of bacterial meningitis, although the activity of this regimen against Listeria monocytogenes remains to be demonstrated.

Clinical features, outcome, and meningococcal genotype in 258 adults with meningococcal meningitis: a prospective cohort study

Meningococcal meningitis remains a life-threatening disease. Neisseria meningitidis is the leading cause of meningitis and septicemia in young adults and is a major cause of endemic bacterial meningitis worldwide. The Meningitis Cohort Study was a Dutch nationwide prospective observational cohort study of adults with community-acquired bacterial meningitis, confirmed by culture of cerebrospinal fluid, from October 1998 to April 2002. Patients underwent a neurologic examination at discharge, and outcome was graded with the Glasgow Outcome Scale. Serogrouping, multi-locus sequence typing, and susceptibility testing of meningococcal isolates were performed. The study identified 258 episodes of meningococcal meningitis in 258 patients. The prevalence of the classical triad of fever, neck stiffness, and change in mental status was low (70/258, 27%). When rash was added to the classical triad, 229 of 258 (89%) patients had at least 2 of 4 signs. Systolic hypotension was associated with rash (22/23 vs. 137/222, p = 0.002) and absence of neck stiffness (6/23 vs. 21/220, p = 0.05). Neuroimaging before lumbar puncture was an important cause of delay of therapy: antibiotics were not initiated before computed tomography (CT) scan in 85% of patients who underwent CT scan before lumbar puncture. Unfavorable outcome occurred in 30 of 258 (12%) patients, including a mortality rate of 7%. Neurologic sequelae occurred in 28 of 238 (12%) patients, particularly hearing loss (8%). Factors associated with sepsis and infection with meningococci of clonal complex 11 (cc11) are related with unfavorable outcome.

Laboratory-based surveillance of patients with bacterial meningitis in Egypt (1998–2004)

Laboratory-based surveillance for bacterial meningitis was conducted in a network of infectious disease hospitals in Egypt to better understand the epidemiology of this infection. Healthcare and laboratory personnel were trained in basic surveillance and microbiologic processing of cerebrospinal fluid (CSF) specimens. All bacterial isolates from CSF were confirmed and tested for antimicrobial susceptibility. PCR testing was performed on a random subset of purulent, culture-negative CSF specimens. Of 11,070 patients who met criteria for the case definition, 843 (8%) were culture positive (42% positive for Streptococcus pneumoniae, 20% for Haemophilus influenzae serotype b, 17% for each of Neisseria meningitidis and Mycobacterium tuberculosis, and 6% for other bacteria). Of 1,784 (46%) CSF specimens tested by PCR, 232 (13%) were positive for the first three major pathogens. Of N. meningitidis isolates, 52% belonged to serogroup A, 35% to serogroup B, and 4% to serogroup W135. S. pneumoniae isolates comprised 46 different serotypes, of which 6B, 1, 19A, 23F, and 6A were the most predominant. The overall case-fatality rate for culture-positive cases was 26% and was highest among patients with M. tuberculosis (47%). Factors significantly associated with death (p < 0.05) included admission to rural hospitals, long prodromal period, referral from other hospitals, antibiotic treatment prior to admission, and clear CSF (<100 cells/mm3). Susceptibility to ampicillin and ceftriaxone was observed in 44 and 100% of H. influenzae serotype b isolates and in 52 and 94% of S. pneumoniae isolates, respectively. This surveillance highlights the significant mortality and morbidity associated with bacterial meningitis in Egypt. Decision makers need to review current treatment guidelines and introduce appropriate vaccines for prevention and control of the disease.

Prognostic factors and determinants of fatal outcome due to bacterial meningitis in the Lazio region of Italy, 1996–2000

OBJECTIVES

To estimate case fatality rates (CFR) of bacterial meningitis and analyze factors associated with mortality due to bacterial meningitis in the Italian region of Lazio.

METHODS

Patients reported with bacterial meningitis during the period 1996-2000, who died within 30 days from hospitalization (cases), were compared with survivors (controls) for factors related to healthcare. Age, gender, residence, bacterial agent, co-morbidities, and signs of disease severity were also analyzed in the final model. Healthcare factors were analyzed using current surveillance databases.

RESULTS

Disease severity (OR=8.84; 95% CI=3.35-23.34) and age >44 years (OR=4.59; 95% CI=2.01-10.48) were the risk factors most strongly associated with death, while treatment in an infectious diseases ward was a protective factor, although modified by patient residence and by co-morbidities.

CONCLUSIONS

This protective effect was possibly due to differences in treatment protocols between the infectious diseases ward and other wards. The protective effect was found to be stronger for residents of Rome, suggesting delayed access to infectious diseases wards for non-residents. The difference in risk of dying from meningitis at younger ages than that found in other studies should be further evaluated, using information on bacteria serogroups and antibiotic susceptibility.

Detrimental role of delayed antibiotic administration and penicillin-nonsusceptible strains in adult intensive care unit patients with pneumococcal meningitis: the PNEUMOREA prospective multicenter study

OBJECTIVE

To identify factors associated with mortality and morbidity among adults admitted to intensive care units (ICUs) for pneumococcal meningitis, particularly the impact of delayed antibiotic administration.

DESIGN

We conducted a prospective, multicenter, observational study of 156 consecutive adults hospitalized for pneumococcal meningitis. We analyzed parameters associated with 3-month survival.

SETTING

Fifty-six medical and medical-surgical ICUs in France.

INTERVENTION

None.

RESULTS

Of the 148 strains isolated, 56 (38%) were nonsusceptible to penicillin G. At 3 months after ICU admission, the mortality rate was 33% (51/156), and 34% of survivors (36/105) had neurologic sequelae. Multivariate analysis identified three variables as independently associated with 3-month mortality: Simplified Acute Physiology Score II (odds ration [OR], 1.12; 95% confidence interval [CI], 1.072-1.153; p = .002); isolation of a nonsusceptible strain (OR, 6.83; 95% CI, 2.94-20.8; p < 10(-4)), and an interval of >3 hrs between hospital admission and administration of antibiotics (OR, 14.12; 95% CI, 3.93-50.9; p < 10(-4)). In contrast, a cerebrospinal fluid leukocyte count >10(3) cells/microL had a protective effect (OR, 0.30; 95% CI, 0.10-0.944; p = 0.04).

CONCLUSIONS

Independent of severity at the time of ICU admission, isolation of penicillin-nonsusceptible strains and a delay in antibiotic treatment following admission were predictors of mortality among patients with pneumococcal meningitis.

Attenuated cerebrospinal fluid leukocyte count and sepsis in adults with pneumococcal meningitis: a prospective cohort study

Background

A low cerebrospinal fluid (CSF) white-blood cell count (WBC) has been identified as an independent risk factor for adverse outcome in adults with bacterial meningitis. Whereas a low CSF WBC indicates the presence of sepsis with early meningitis in patients with meningococcal infections, the relation between CSF WBC and outcome in patients with pneumococcal meningitis is not understood.

Methods

We examined the relation between CSF WBC, bacteraemia and sepsis in a prospective cohort study that included 352 episodes of pneumococcal meningitis, confirmed by CSF culture, occurring in patients aged >16 years.

Results

CSF WBC was recorded in 320 of 352 episodes (91%). Median CSF WBC was 2530 per mm³ (interquartile range 531–6983 per mm³) and 104 patients (33%) had a CSF WBC <1000/mm³. Patients with a CSF WBC <1000/mm³ were more likely to have an unfavourable outcome (defined as a Glasgow Outcome Scale score of 1–4) than those with a higher WBC (74 of 104 [71%] vs. 87 of 216 [43%]; P < 0.001). CSF WBC was significantly associated with blood WBC (Spearman's test 0.29), CSF protein level (0.20), thrombocyte count (0.21), erythrocyte sedimentation rate (-0.15), and C-reactive protein levels (-0.18). Patients with a CSF WBC <1000/mm³ more often had a positive blood culture (72 of 84 [86%] vs. 138 of 196 [70%]; P = 0.01) and more often developed systemic complications (cardiorespiratory failure, sepsis) than those with a higher WBC (53 of 104 [51%] vs. 69 of 216 [32%]; P = 0.001). In a multivariate analysis, advanced age (Odds ratio per 10-year increments 1.22, 95%CI 1.02–1.45), a positive blood culture (Odds ratio 2.46, 95%CI 1.17–5.14), and a low thrombocyte count on admission (Odds ratio per 100,000/mm³ increments 0.67, 95% CI 0.47–0.97) were associated with a CSF WBC <1000/mm³.

Conclusion

A low CSF WBC in adults with pneumococcal meningitis is related to the presence of signs of sepsis and systemic complications. Invasive pneumococcal infections should possibly be regarded as a continuum from meningitis to sepsis.

Community-acquired Listeria monocytogenes meningitis in adults

BACKGROUND

Listeria monocytogenes is the third most common cause of bacterial meningitis.

METHODS

We prospectively evaluated 30 episodes of community-acquired L. monocytogenes meningitis, confirmed by culture of cerebrospinal fluid specimens, in a nationwide study in The Netherlands. Outcome was graded using the Glasgow outcome score; an unfavorable outcome was defined as a score of 1-4.

RESULTS

We found 30 episodes of L. monocytogenes meningitis. All patients were immunocompromised or > 50 years old. In 19 (63%) of 30 patients, symptoms were present for > 24 h; in 8 patients (27%), symptoms were present for > or = 4 days. The classic triad of fever, neck stiffness, and change in mental status was present in 13 (43%) of 30 patients. An individual cerebrospinal fluid indicator of bacterial meningitis was present in 23 (77%) of 30 cases. Gram staining of cerebrospinal fluid samples revealed the causative organism in 7 (28%) of 25 cases. The initial antimicrobial therapy was amoxicillin based for 21 (70%) of 30 patients. The coverage of initial antimicrobial therapy was microbiologically inadequate for 9 (30%) of the patients. The mortality rate was 17% (5 of 30), and 8 (27%) of 30 patients experienced an unfavorable outcome. Inadequate initial antimicrobial therapy was not related to outcome.

CONCLUSIONS

In contrast with previous reports, we found that patients with meningitis due to L. monocytogenes do not present with atypical clinical features; however, typical cerebrospinal fluid findings predictive for bacterial meningitis might be absent. A high proportion of patients received initial antimicrobial therapy that did not cover L. monocytogenes.

Pneumococcal meningitis in adults: new approaches to management and prevention

Since the virtual eradication of meningitis due to Haemophilus influenzae type B by vaccination in the developed world, pneumococcal meningitis has become the leading cause of bacterial meningitis beyond the neonatal period. Clinical and experimental research has increased our knowledge about the pathophysiology and pathogenesis of the disease over the past decades. Despite the availability of effective antibiotics, supportive care facilities, and recent advances in adjunctive strategies-ie, adjunctive dexamethasone-mortality and morbidity rates associated with pneumococcal meningitis remain unacceptably high. Although preliminary results after the introduction of the pneumococcal conjugate vaccine are promising, the incidence of multidrug-resistant pneumococcal strains is rising worldwide. Here we discuss clinical aspects of pneumococcal meningitis in adults, with focus on pathophysiology, and stress the urgent need for adequate preventive measures and new effective treatments.

Clinical features, complications, and outcome in adults with pneumococcal meningitis: a prospective case series

BACKGROUND

Bacterial meningitis is a grave disease of high incidence, especially in less developed countries. Here, we describe its clinical presentation, spectrum of complications, prognostic factors, and outcome in adults with pneumococcal meningitis.

METHODS

From October, 1998, to April, 2002, we assessed 352 episodes of community-acquired pneumococcal meningitis, confirmed by culture of cerebrospinal fluid (CSF), which occurred in patients older than 16 years. Predictors for an unfavourable outcome (Glasgow outcome scale score 1-4) were identified by logistic regression with multiple imputation techniques.

FINDINGS

245 (70%) episodes of pneumococcal meningitis were associated with an underlying disorder. Cranial CT was done for 85% of episodes and revealed underlying disorders in 17% (50/299) and meningitis-associated intracranial complications in 39% (117/299). Independent predictors for an unfavourable outcome were a low score on the Glasgow coma scale, cranial nerve palsies, a raised erythrocyte sedimentation rate, a CSF leucocyte count less than 1000 cells per mm(3), and a high CSF protein concentration on admission. Overall in-hospital mortality was 30%. Prevalence of neurological and systemic complications did not differ between patients aged younger than 60 years and those aged 60 years and older; however, systemic complications were the cause of death in 59% (32/54) of fatal episodes in patients aged 60 years and older, whereas neurological complications were the cause of death in 65% (20/31) of fatal episodes in younger patients.

INTERPRETATION

Pneumococcal meningitis is associated with high mortality and morbidity rates in adults. Whereas neurological complications are the leading cause of death in younger patients, elderly patients die predominantly from systemic complications.

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

Background

We conducted a nationwide study in Denmark to identify clinical features and prognostic factors in patients with Streptococcus pneumoniae according to the focus of infection.

Methods

Based on a nationwide registration, clinical information's was prospectively collected from all reported cases of pneumococcal meningitis during a 2-year period (1999–2000). Clinical and laboratory findings at admission, clinical course and outcome of the disease including follow-up audiological examinations were collected retrospectively. The focus of infection was determined according to the clinical diagnosis made by the physicians and after review of the medical records.

Results

187 consecutive cases with S. pneumoniae meningitis were included in the study. The most common focus was ear (30%), followed by lung (18%), sinus (8%), and other (2%). In 42% of cases a primary infection focus could not be determined. On admission, fever and an altered mental status were the most frequent findings (in 93% and 94% of cases, respectively), whereas back rigidity, headache and convulsion were found in 57%, 41% and 11% of cases, respectively. 21% of patients died during hospitalisation (adults: 27% vs. children: 2%, Fisher Exact Test, P < 0.001), and the causes of death were due to neurological – and systemic complications or the combination of both in 8%, 5% and 6% of cases, respectively. Other causes (e.g. gastrointestinal bleeding, incurable cancer) accounted for 2% of cases. 41% of survivors had neurological sequelae (hearing loss: 24%, focal neurological deficits: 16%, and the combination of both: 1%). The mortality varied with the focus of the infection (otogenic: 7%, sinusitic: 33%, pneumonic: 26%, other kind of focus: 50%, no primary infection focus: 21%, Log rank test: P = 0.0005). Prognostic factors associated with fatal outcome in univariate logistic regression analysis were advanced age, presence of an underlying disease, history of headache, presence of a lung focus, absence of an otogenic focus, having a CT-scan prior to lumbar puncture, convulsions, requirement of assisted ventilation, and alterations in various CSF parameters (WBC <500 cells/μL, high protein levels, glucose levels<1 mmol/L, low CSF/blood glucose levels), P < 0.05. Independent prognostic factor associated with fatal outcome in multivariate logistic regression analysis was convulsions (OR: 4.53, 95%CI: (1.74–11.8), p = 0.002), whereas presence of an otogenic focus was independently associated with a better survival (OR: 6.09, 95%CI: (1.75–21.2), P = 0.005).

Conclusion

These results emphasize the prognostic importance of an early recognition of a predisposing focus to pneumococcal meningitis.

Drotrecogin alfa (activated) in patients with severe sepsis presenting with purpura fulminans, meningitis, or meningococcal disease: a retrospective analysis of patients enrolled in recent clinical studies

INTRODUCTION

We report data from adult and pediatric patients with severe sepsis from studies evaluating drotrecogin alfa (activated) (DrotAA) and presenting with purpura fulminans (PF), meningitis (MEN), or meningococcal disease (MD) (PF/MEN/MD). Such conditions may be associated with an increased bleeding risk but occur in a relatively small proportion of patients presenting with severe sepsis; pooling data across clinical trials provides an opportunity for improving the characterization of outcomes.

METHODS

A retrospective analysis of placebo-controlled, open-label, and compassionate-use trials was conducted. Adult patients received infusions of either DrotAA or placebo. All pediatric patients (<18 years old) received DrotAA. 189 adult and 121 pediatric patients presented with PF/MEN/MD.

RESULTS

Fewer adult patients with PF/MEN/MD met cardiovascular (68.3% versus 78.8%) or respiratory (57.8% versus 80.5%) organ dysfunction entry criteria than those without. DrotAA-treated adult patients with PF/MEN/MD (n = 163) had an observed 28-day mortality rate of 19.0%, a 28-day serious bleeding event (SBE) rate of 6.1%, and an intracranial hemorrhage (ICH) rate of 4.3%. Six of the seven ICHs occurred in patients with MEN (three of whom were more than 65 years old with a history of hypertension). DrotAA-treated adult patients without PF/MEN/MD (n = 3,088) had an observed 28-day mortality rate of 25.5%, a 28-day SBE rate of 5.8%, and an ICH rate of 1.0%. In contrast, a greater number of pediatric patients with PF/MEN/MD met the cardiovascular organ dysfunction entry criterion (93.5% versus 82.5%) than those without. DrotAA-treated PF/MEN/MD pediatric patients (n = 119) had a 14-day mortality rate of 10.1%, an SBE rate of 5.9%, and an ICH rate of 2.5%. DrotAA-treated pediatric patients without PF/MEN/MD (n = 142) had a 14-day mortality rate of 14.1%, an SBE rate of 9.2%, and an ICH rate of 3.5%.

CONCLUSION

DrotAA-treated adult patients with severe sepsis presenting with PF/MEN/MD had a similar SBE rate, a lower observed 28-day mortality rate, and a higher observed rate of ICH than DrotAA-treated patients without PF/MEN/MD. DrotAA-treated pediatric patients with severe sepsis with PF/MEN/MD may differ from adults, because all three outcome rates (SBE, mortality, and ICH) were lower in pediatric patients with PF/MEN/MD.

Delays in the administration of antibiotics are associated with mortality from adult acute bacterial meningitis

BACKGROUND

Bacterial meningitis continues to cause high mortality. Few studies address the possible association between this mortality and antibiotic administration delays.

AIM

To determine whether delays in antibiotic administration are associated with mortality from bacterial meningitis, and to identify inappropriate diagnostic-treatment sequences leading to such delays.

DESIGN

Retrospective case record study.

METHODS

We reviewed 123 cases of adult acute bacterial meningitis in 119 patients aged >/=16 years admitted to hospital from January 1990 to March 2002, using multivariate regression analysis to assess the association between meningitis mortality and door-to-antibiotic time (the time elapsed between emergency room presentation and antibiotics administration).

RESULTS

The case fatality rate was 13% (16/123). Adjusted odds ratios (OR) for mortality were: 8.4 (95%CI 1.7-40.9) for door-to-antibiotic time >6 h; 39.4 (95%CI 4.3-358.1) for afebrility at presentation; and 12.6 (95%CI 2.2-72.0) for severely impaired mental status at presentation. Factors associated with a door-to-antibiotic time of >6 h were: (i) failure to administer antibiotics prior to transfer from another institution (OR 21.8); (ii) the diagnostic-treatment sequence: head CT then lumbar puncture, then antibiotics (OR 5.6); and (iii) the absence of the classic meningitis triad (OR 4.9).

DISCUSSION

There is an independent incremental association between delays in administrating antibiotics and mortality from adult acute bacterial meningitis. Inappropriate diagnostic-treatment sequences were significant predictors of such treatment delays.

Clinical features and prognostic factors in adults with bacterial meningitis

BACKGROUND

We conducted a nationwide study in the Netherlands to determine clinical features and prognostic factors in adults with community-acquired acute bacterial meningitis.

METHODS

From October 1998 to April 2002, all Dutch patients with community-acquired acute bacterial meningitis, confirmed by cerebrospinal fluid cultures, were prospectively evaluated. All patients underwent a neurologic examination on admission and at discharge, and outcomes were classified as unfavorable (defined by a Glasgow Outcome Scale score of 1 to 4 points at discharge) or favorable (a score of 5). Predictors of an unfavorable outcome were identified through logistic-regression analysis.

RESULTS

We evaluated 696 episodes of community-acquired acute bacterial meningitis. The most common pathogens were Streptococcus pneumoniae (51 percent of episodes) and Neisseria meningitidis (37 percent). The classic triad of fever, neck stiffness, and a change in mental status was present in only 44 percent of episodes; however, 95 percent had at least two of the four symptoms of headache, fever, neck stiffness, and altered mental status. On admission, 14 percent of patients were comatose and 33 percent had focal neurologic abnormalities. The overall mortality rate was 21 percent. The mortality rate was higher among patients with pneumococcal meningitis than among those with meningococcal meningitis (30 percent vs. 7 percent, P<0.001). The outcome was unfavorable in 34 percent of episodes. Risk factors for an unfavorable outcome were advanced age, presence of otitis or sinusitis, absence of rash, a low score on the Glasgow Coma Scale on admission, tachycardia, a positive blood culture, an elevated erythrocyte sedimentation rate, thrombocytopenia, and a low cerebrospinal fluid white-cell count.

CONCLUSIONS

In adults presenting with community-acquired acute bacterial meningitis, the sensitivity of the classic triad of fever, neck stiffness, and altered mental status is low, but almost all present with at least two of the four symptoms of headache, fever, neck stiffness, and altered mental status. The mortality associated with bacterial meningitis remains high, and the strongest risk factors for an unfavorable outcome are those that are indicative of systemic compromise, a low level of consciousness, and infection with S. pneumoniae.

Pneumococcal meningitis in adults: spectrum of complications and prognostic factors in a series of 87 cases

Studies on the incidence and spectrum of complications and prognostic factors in adults with pneumococcal meningitis are scarce. Therefore, we analysed 87 consecutive cases who were treated in our department between 1984 and 2002. Meningitis-associated intracranial complications developed in 74.7% and systemic complications in 37.9% of cases. Diffuse brain oedema (28.7%) and hydrocephalus (16.1%) developed more frequently than previously reported. The incidences of arterial (21.8%) and venous (9.2%) cerebrovascular complications were also very high. Furthermore, 9.2% of cases developed spontaneous intracranial haemorrhages (two patients with subarachnoid and two with subarachnoid and intracerebral bleedings, all in association with vasculitis; one subject with intracerebral haemorrhage due to sinus thrombosis; and three cases with intracerebral bleedings of unknown aetiology). Other new findings were the incidence of acute spinal cord dysfunction due to myelitis (2.3%) and that of hearing loss (19.5% of all patients and 25.8% of survivors). The in-hospital mortality was 24.1%. Only 48.3% of the patients had a good outcome at discharge [Glasgow Outcome Scale Score (GOS) = 5]. Outcome did not change during the study period, as mortality and GOS were similar for patients treated between 1984 and 1992 and for those treated between 1993 and 2002. Factors associated with a bad outcome (GOS </= 4) were chronic debilitating diseases, low Glasgow Coma Scale Score and focal neurological deficits on admission, low CSF leucocyte counts, pneumonia, bacteraemia and meningitis-associated intracranial and systemic complications. Low CSF leucocyte counts were also associated with the development of meningitis-associated intracranial complications. Age > or =60 years was associated with a higher mortality (36.7 versus 17.5%), but the GOS of the survivors was comparable to that of the surviving younger patients. The causes of death were mostly systemic complications in the elderly and cerebral complications in the younger patients. A haematogenous pathogenesis seemed likely in asplenic patients, while contiguous spread from sinusitis or otitis was the major cause of meningitis in non-asplenic individuals. Furthermore, asplenic patients had a raised incidence of meningitis-associated intracranial complications, but their outcome was similar to that of non-asplenic subjects. The morbidity and mortality of pneumococcal meningitis in adults are still devastating. We report higher incidences (diffuse brain swelling, hydrocephalus, cerebrovascular complications) or new incidences (myelitis, hearing loss, subarachnoid bleeding) of intracranial complications. Our detailed analysis of prognostic factors may help clinicians to identify patients at risk and may also be helpful in the design of clinical trials.

Pathogenesis and pathophysiology of pneumococcal meningitis

Until the introduction of antibiotics in the 1930s and 1940s, acute bacterial meningitis was fatal in most cases. Since then it has become curable with a variable mortality and morbidity rate for individual pathogens and patients. Neuropathological and clinical studies have shown that a fatal outcome of the disease is often due to central nervous system (CNS) complications including cerebrovascular involvement, brain oedema formation, and hydrocephalus resulting in increased intracranial pressure and seizure activity. During recent years, experimental studies with animal models have substantially increased our knowledge of the interactions of bacterial pathogens with mammalian cells and their entry into the CNS, and the complex pathophysiological mechanisms of brain dysfunction during acute bacterial meningitis. There is now a substantial body of evidence that cytokines, chemokines, proteolytic enzymes, and oxidants are involved in the inflammatory cascade that leads to tissue destruction in bacterial meningitis. Genetic targeting and/or pharmacological blockade of these pathways was beneficial in experimental bacterial meningitis. Apart from dexamethasone, these treatment strategies hold major promise for the adjunctive therapy of acute bacterial meningitis in clinical practice.