Clinical characteristics and prognosis of acute bacterial meningitis in elderly patients over 65: a hospital-based study

Post-Infectious Inflammatory Response Syndrome in an HIV-Negative Immunocompetent Elderly Patient With Cryptococcal Meningitis: A Case Report and Literature Review

We report a previously healthy 82-year-old male with cryptococcal meningitis (CM) who represented neurological deterioration due to post-infectious inflammatory response syndrome (PIIRS) occurring in 4 months after initial antifungal therapy. He was treated with corticosteroids for 2 months and recovered clinically. However, the clinical manifestation, cerebrospinal fluid (CSF), and brain magnetic resonance imaging (MRI) results got worse again on the next day after corticosteroid withdrawal. The analysis of inflammatory cytokines and culture on CSF, as well as brain MRI, still suggested a diagnosis of PIIRS. Therefore, corticosteroid therapy was used again and he subsequently obtained a complete resolution of symptoms.

Neuroinfectious Disease Emergencies

Neuroinfectious diseases can affect immunocompetent and immunosuppressed individuals and cause a variety of emergencies including meningitis, encephalitis, and abscess. Neurologic infections are frequently complicated by secondary injuries that also present emergently such as cerebrovascular disease, acute obstructive hydrocephalus, and seizure. In most cases, timely recognition and early treatment of infection can improve the morbidity and mortality of infectious neurologic emergencies.

Neurologic Emergencies at the Extremes of Age

The diagnosis and management of neurologic conditions are more complex at the extremes of age than in the average adult. In the pediatric population, neurologic emergencies are somewhat rare and some may require emergent consultation. In older adults, geriatric physiologic changes with increased comorbidities leads to atypical presentations and worsened outcomes. The unique considerations regarding emergency department presentation and management of stroke and altered mental status in both age groups is discussed, in addition to seizures and intracranial hemorrhage in pediatrics, and Parkinson's disease and meningitis in the geriatric population.

Coagulase-negative staphylococci (CoNS) meningitis: a narrative review of the literature from 2000 to 2020

Coagulase-negative staphylococci (CoNS) are recognized as comprising the main part of human normal microbiota and are rarely associated with severe and intensive infections. However, these organisms can cause a number of infections in humans, especially immunocompromised patients and neonates. Bacterial meningitis, as an important and acute infection in the central nervous system, is still a major global health challenge and a serious infectious disease, causing a high rate of mortality and morbidity. CoNS as causative agents of meningitis are generally related to trauma or direct implantation of foreign bodies and the presence of a cerebrospinal fluid shunt. Numerous epidemiologic and clinical studies have shown that different CoNS isolates such as Staphylococcus capitis, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus epidermidis, Staphylococcus schleiferi, Staphylococcus saprophyticus, Staphylococcus warneri and Staphylococcus haemolyticus are more frequently associated with meningitis. This study attempts to determine the role of CoNS in meningitis and reviews the reported cases of meningitis induced by CoNS from the year 2000 to 2020 in the literature.

Post-Traumatic Meningitis Is a Diagnostic Challenging Time: A Systematic Review Focusing on Clinical and Pathological Features

Post-traumatic meningitis is a dreadful condition that presents additional challenges, in terms of both diagnosis and management, when compared with community-acquired cases. Post-traumatic meningitis refers to a meningeal infection causally related to a cranio-cerebral trauma, regardless of temporal proximity. The PICO (participants, intervention, control, and outcomes) question was as follows: "Is there an association between traumatic brain injury and post-traumatic meningitis?" The present systematic review was carried out according to the Preferred Reporting Items for Systematic Review (PRISMA) standards. Studies examining post-traumatic meningitis, paying particular attention to victims of traumatic brain injury, were included. Post-traumatic meningitis represents a high mortality disease. Diagnosis may be difficult both because clinical signs are nonspecific and blurred and because of the lack of pathognomonic laboratory markers. Moreover, these markers increase with a rather long latency, thus not allowing a prompt diagnosis, which could improve patients' outcome. Among all the detectable clinical signs, the appearance of cranial cerebrospinal fluid (CSF) leakage (manifesting as rhinorrhea or otorrhea) should always arouse suspicion of meningitis. On one hand, microbiological exams on cerebrospinal fluid (CSF), which represent the gold standard for the diagnosis, require days to get reliable results. On the other hand, radiological exams, especially CT of the brain, could represent an alternative for early diagnosis. An update on these issues is certainly of interest to focus on possible predictors of survival and useful tools for prompt diagnosis.

[Extra-ventricular drainage for the treatment of pneumococcal meningitis and hydrocephalus: a case report]

A 53-year-old man was referred to our hospital because of fever and disturbed consciousness with a left-sided toothache from 5 days ago. Neurological examinations revealed a low level of consciousness, nuchal rigidity, bilateral mydriasis, and positive Babinski sign. A lumbar puncture yielded clouded fluid with a WBC 22,698/μl (polynuclear cell 98%), 681 mg/dl of protein and 0 mg/dl of glucose. The antigen of Streptococcus pneumoniae in urine and cerebrospinal fluid (CSF) were positive. Streptococcus pneumoniae was isolated from CSF culture. Brain CT on admission showed a communicating hydrocephalus. Diagnosis of pneumococcal meningitis with hydrocephalus was made and we treated with ceftriaxone and dexamethasone. The lumbar drainage placed at L 3/4 level became occluded, thus, extra-ventricular drainage was performed. Intracranial pressure (ICP) was 20 cmH₂O upon insertion of the ICP sensor. At Day 2, the ICP decreased to 10 cmH₂O and never increased during his course of hospitalization. Repeat brain CT showed no hydrocephalus. He responded to antimicrobial therapy and became lucid and afebrile. At Day 4, the extra-ventricular drainage was removed because of bleeding from right choroid plexus on brain CT. We treated with antimicrobial therapy until Day 21. He was transferred to another hospital for rehabilitation with mild neurological sequelae at Day 31. The cases presenting with hydrocephalus in the acute phase of bacterial meningitis has a high mortality rate. The presence of hydrocephalus is a poor prognostic factor. Although the therapeutic value of extra-ventricular drainage for hydrocephalus has been unclear, his report represents a case for neurologists to consider performing extra-ventricular drainage for hydrocephalus.

Risk factors and prognosis of seizures in adults with community-acquired bacterial meningitis in Denmark: observational cohort studies

OBJECTIVE

To examine predefined risk factors and outcome of seizures in community-acquired bacterial meningitis (CABM).

DESIGN

Observational cohort studies SETTING: Denmark PARTICIPANTS: In the derivation cohort, we retrospectively included all adults (>15 years of age) with CABM in North Denmark Region from 1998 to 2014 and at Hvidovre and Hillerød hospitals from 2003 to 2014. In the validation cohort, we prospectively included all adults (>18 years of age) with CABM treated at all departments of infectious diseases in Denmark from 2015 to 2017.

PRIMARY AND SECONDARY OUTCOME MEASURES

In the derivation cohort, we used modified Poisson regression to compute adjusted relative risks (RRs) with 95% confidence intervals for predefined risk factors for seizures during CABM as well as for risks of death and unfavourable outcome assessed by the Glasgow Outcome Scale score (1-4). Next, results were validated in the validation cohort.

RESULTS

In the derivation cohort (n=358), risk factors for seizures at any time were pneumococcal aetiology (RR 1.69, 1.01-2.83) and abnormal cranial imaging (RR 2.27, 1.46-3.53), while the impact of age >65 years and immunocompromise was more uncertain. Examining seizures occurring after admission, risk factors were abnormal cranial imaging (RR 2.23, 1.40-3.54) and immunocompromise (RR 1.59, 1.01-2.50). Seizures at any time were associated with increased risks of in-hospital mortality (RR 1.45, 1.01-2.09) and unfavourable outcome at discharge (RR 1.27, 1.02-1.60). In the validation cohort (n=379), pneumococcal aetiology (RR 1.69, 1.10-2.59) and abnormal cranial imaging (RR 1.68, 1.09-2.59) were confirmed as risk factors for seizures at any time. For seizures occurring after admission, only pneumococcal meningitis (RR 1.92, 1.12-3.29) remained significant. Seizures at any time were also associated with in-hospital mortality (RR 3.26, 1.83-5.80) and unfavourable outcome (RR 1.23, 1.00-1.52) in this cohort.

CONCLUSIONS

Pneumococcal aetiology, immunocompromise and abnormal cranial imaging were risk factors for seizures in CABM. Seizures were strongly associated with mortality and unfavourable outcome.

Usefulness of the FilmArray meningitis/encephalitis (M/E) panel for the diagnosis of infectious meningitis and encephalitis in Taiwan

BACKGROUND/PURPOSE

Early recognition of causative pathogens is critical for the appropriate management of central nervous system infection and improved outcomes. The BioFire^® FilmArray^® Meningitis/Encephalitis Panel (BioFire^® ME Panel, BioFire Diagnostics) is the first U.S. Food and Drug Administration (FDA)-approved multiplex PCR assay that allows the rapid detection of 14 pathogens, including bacteria (n = 6), viruses (n = 7), and fungi (n = 1), from cerebrospinal fluid (CSF). The performance of the panel is expected to be dependent on the epidemiology of M/E in different geographical regions.

METHODS

In this preliminary study, we used the BioFire^® ME Panel in 42 subjects who presented to the emergency department with symptoms of M/E in our hospital. The results were compared to conventional culture, antigen detection, PCR, and various laboratory findings.

RESULTS

The panel detected six positive samples, of which five were viral and one bacterial. We observed an overall agreement rate of 88% between the BioFire^® ME Panel results and the conventional methods. There were no false-positive findings, but five discordant results were observed for enterovirus, herpes simplex virus type 1, Escherichia coli, and Cryptococcus species.

CONCLUSIONS

The BioFire^® ME Panel performed equivalently to the traditional PCR methods for virus detection, and better than bacterial cultures. This revolutionary system represents a paradigm shift in the diagnosis of M/E and may aid in the rapid identification of community-acquired M/E. However, the usefulness of this tool is limited in regions with a high prevalence of infectious M/E caused by microorganisms not included in the panel.

The clinical characteristics and therapeutic outcomes of cryptococcal meningitis in elderly patients: a hospital-based study

BACKGROUND

The elderly, and especially those with an immuno-compromised status, are vulnerable to infectious diseases. The purpose of this study was to examine the clinical characteristics and therapeutic outcomes of cryptococcal meningitis (CM) in elderly patients in Taiwan.

METHODS

Ninety-nine adult patients with CM were identified during a 15-year study period (2002-2016), of whom 38 elderly (≥ 65 years) patients (16 men and 22 women, median age 72.9 years; range 65-86 years) were included for analysis. The clinical characteristics and therapeutic outcomes of these patients were analyzed and compared to non-elderly adult patients (< 65 years) with CM.

RESULTS

Among the 38 patients, diabetes mellitus was the most common underlying condition (15), followed by adrenal insufficiency (7), malignancy (6), hematologic disorders (5), chronic obstructive pulmonary disease (5), autoimmune diseases (3), liver cirrhosis (3) and acquired immunodeficiency syndrome (1). Altered consciousness (29), fever (21) and headache (17) were the leading clinical manifestations. Positive cerebrospinal fluid and blood cultures for Cryptococcus (C.) neoformans were found in 26 and 9 patients, respectively. There were significant differences in gender, altered consciousness and recent cerebral infarction between the elderly and non-elderly groups. The elderly group had a high mortality rate (36.8%, 14/38), and the presence of cryptococcemia was the most significant prognostic factor.

CONCLUSIONS

This study offers a preliminary view of the clinical characteristics of CM in the elderly. The results suggest that elderly patients (≥ 65 years) are more vulnerable to CM than adults aged < 65 years. Compared to the non-elderly group, the elderly group had female predominance, higher rates of altered consciousness and recent cerebral infarction as the clinical presentation. The presence of cryptococcemia was a significant prognostic factor in the elderly group. This study is limited by the small number of patients, and further large-scale studies are needed to better delineate this specific infectious syndrome.

Prophylactic Palmitoylethanolamide Prolongs Survival and Decreases Detrimental Inflammation in Aged Mice With Bacterial Meningitis

Easy-to-achieve interventions to promote healthy longevity are desired to diminish the incidence and severity of infections, as well as associated disability upon recovery. The dietary supplement palmitoylethanolamide (PEA) exerts anti-inflammatory and neuroprotective properties. Here, we investigated the effect of prophylactic PEA on the early immune response, clinical course, and survival of old mice after intracerebral E. coli K1 infection. Nineteen-month-old wild type mice were treated intraperitoneally with two doses of either 0.1 mg PEA/kg in 250 μl vehicle solution (n = 19) or with 250 μl vehicle solution only as controls (n = 19), 12 h and 30 min prior to intracerebral E. coli K1 infection. The intraperitoneal route was chosen to reduce distress in mice and to ensure exact dosing. Survival time, bacterial loads in cerebellum, blood, spleen, liver, and microglia counts and activation scores in the brain were evaluated. We measured the levels of IL-1β, IL-6, MIP-1α, and CXCL1 in cerebellum and spleen, as well as of bioactive lipids in serum in PEA- and vehicle-treated animals 24 h after infection. In the absence of antibiotic therapy, the median survival time of PEA-pre-treated infected mice was prolonged by 18 h compared to mice of the vehicle-pre-treated infected group (P = 0.031). PEA prophylaxis delayed the onset of clinical symptoms (P = 0.037). This protective effect was associated with lower bacterial loads in the spleen, liver, and blood compared to those of vehicle-injected animals (P ≤ 0.037). PEA-pre-treated animals showed diminished levels of pro-inflammatory cytokines and chemokines in spleen 24 h after infection, as well as reduced serum concentrations of arachidonic acid and of one of its metabolites, 20-hydroxyeicosatetraenoic acid. In the brain, prophylactic PEA tended to reduce bacterial titers and attenuated microglial activation in aged infected animals (P = 0.042). Our findings suggest that prophylactic PEA can counteract infection associated detrimental responses in old animals. Accordingly, PEA treatment slowed the onset of infection symptoms and prolonged the survival of old infected mice. In a clinical setting, prophylactic administration of PEA might extend the potential therapeutic window where antibiotic therapy can be initiated to rescue elderly patients.

Neurologic Emergencies in the Elderly

Neurologic diseases are a major cause of death and disability in elderly patients. Due to the physiologic changes and increased comorbidities that occur as people age, neurologic diseases are more common in geriatric patients and a major cause of death and disability in this population. This article discusses the elderly patient presenting to the emergency department with acute ischemic stroke, transient ischemic attack, intracerebral hemorrhage, subarachnoid hemorrhage, chronic subdural hematoma, traumatic brain injury, seizures, and central nervous system infections. This article reviews the subtle presentations, difficult workups, and complicated treatment decisions as they pertain to our older patients."

Systemic inflammatory response syndrome is more associated with bacteremia in elderly patients with suspected sepsis in emergency departments

Early diagnosis of bacteremia for patients with suspected sepsis is 1 way to improve prognosis of sepsis. Systemic inflammatory response syndrome (SIRS) has long been utilized as a screening tool to detect bacteremia by front-line healthcare providers. The value of SIRS to predict bacteremia in elderly patients (≥65 years) with suspected sepsis has not yet been examined in emergency departments (EDs).We aimed to evaluate the performance of SIRS components in predicting bacteremia among elderly patients in EDs.We retrospectively evaluated patients with suspected sepsis and 2 sets of blood culture collected within 4 hours after admitting to ED in a tertiary teaching hospital between 2010 and 2012. Patients were categorized into 3-year age groups: young (18-64 years), young-old (65-74 years), and old patients (≥75 years). Vital signs and Glasgow Coma Scale with verbal response obtained at the triage, comorbidities, sites of infection, blood cultures, and laboratory results were retrieved via the electronic medical records.A total of 20,192 patients were included in our study. Among them, 9862 (48.9%) were the elderly patients (young-old and old patients), 2656 (13.2%) developed bacteremia. Among patients with bacteremia, we found the elderly patients had higher SIRS performance (adjusted odds ratio [aOR]: 2.40, 95% confidence interval [CI]: 1.90-3.03 in the young-old and aOR: 2.66, 95% CI: 2.19-3.23 in the old). Fever at the triage was most predictive of bacteremia, especially in the elderly patients (aOR: 2.19, 95% CI: 1.81-2.65 in the young-old and aOR: 2.27, 95% CI: 1.95-2.63 in the old), and tachypnea was not predictive of bacteremia among the elderly patients (all P > 0.2).The performance of SIRS to predict bacteremia was more suitable for elderly patients in EDs observed in this study. The elderly patients presented with more fever and less tachypnea when they had bacteremia.

Bacterial meningitis in diabetes patients: a population-based prospective study

Diabetes mellitus is associated with increased infection rates. We studied clinical features and outcome of community-acquired bacterial meningitis in diabetes patients. Patients were selected from a nationwide, prospective cohort on community-acquired bacterial meningitis performed from March 2006 to October 2014. Data on patient history, symptoms and signs on admission, treatment, and outcome were prospectively collected. A total of 183 of 1447 episodes (13%) occurred in diabetes patients. The incidence of bacterial meningitis in diabetes patients was 3.15 per 100,000 patients per year and the risk of acquiring bacterial meningitis was 2.2-fold higher for diabetes patients. S. pneumoniae was the causative organism in 139 of 183 episodes (76%) and L. monocytogenes in 11 of 183 episodes (6%). Outcome was unfavourable in 82 of 183 episodes (45%) and in 43 of 183 episodes (23%) the patient died. Diabetes was associated with death with an odds ratio of 1.63 (95% CI 1.12–2.37, P = 0.011), which remained after adjusting for known predictors of death in a multivariable analysis (OR 1.98 [95% CI 1.13–3.48], P = 0.017). In conclusion, diabetes is associated with a 2-fold higher risk of acquiring bacterial meningitis. Diabetes is a strong independent risk factor for death in community-acquired adult bacterial meningitis.

Diagnosis and Treatment of Central Nervous System Infections in the Emergency Department

Central nervous system (CNS) infections, including meningitis, encephalitis, and brain abscess, are rare but time-sensitive emergency department (ED) diagnoses. Patients with CNS infection can present to the ED with nonspecific signs and symptoms, including headache, fever, altered mental status, and behavioral changes. Neuroimaging and CSF fluid analysis can appear benign early in the course of disease. Delaying therapy negatively impacts outcomes, particularly with bacterial meningitis and herpes simplex virus encephalitis. Therefore, diagnosis of CNS infection requires vigilance and a high index of suspicion based on the history and physical examination, which must be confirmed with appropriate imaging and laboratory evaluation.

Sepsis and Other Infectious Disease Emergencies in the Elderly

Waning immunity and declining anatomic and physiologic defenses render the elder vulnerable to a wide range of infectious diseases. Clinical presentations are often atypical and muted, favoring global changes in mental status and function over febrile responses or localizing symptoms. This review encompasses early recognition, evaluation, and appropriate management of these common infections specifically in the context of elders presenting to the emergency department. With enhanced understanding and appreciation of the unique aspects of infections in the elderly, emergency physicians can play an integral part in reducing the morbidity and mortality associated with these often debilitating and life-threatening diseases.

The combination of decoy receptor 3 and soluble triggering receptor expressed on myeloid cells-1 for the diagnosis of nosocomial bacterial meningitis

Background

Early diagnosis and appropriate antibiotic treatment can significantly reduce mortality of nosocomial bacterial meningitis. However, it is a challenge for clinicians to make an accurate and rapid diagnosis of bacterial meningitis. This study aimed at determining whether combined biomarkers can provide a useful tool for the diagnosis of bacterial meningitis.

Methods

A retrospective study was carried out. Cerebrospinal fluid (CSF) levels of decoy receptor 3 (DcR3) and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) were detected by enzyme-linked immunosorbent assay (ELISA).

Results

The patients with bacterial meningitis had significantly elevated levels of the above mentioned biomarkers. The two biomarkers were all risk factors with bacterial meningitis. The biomarkers were constructed into a “bioscore”. The discriminative performance of the bioscore was better than that of each biomarker, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.842 (95% confidence intervals (CI) 0.770–0.914; p< 0.001).

Conclusions

Combined measurement of CSF DcR3 and sTREM-1 concentrations improved the prediction of nosocomial bacterial meningitis. The combined strategy is of interest and the validation of that improvement needs further studies.

Community-acquired meningitis in older adults: clinical features, etiology, and prognostic factors

OBJECTIVES

To investigate the epidemiology and outcomes of community-acquired meningitis in older adults.

DESIGN

Retrospective study.

SETTING

Participants adults in Houston, Texas, with community-acquired meningitis hospitalized between January 1, 2005, and January 1, 2010 (N = 619; n = 54, 8.7%, aged ≥65; n = 565 aged <65).

METHODS

An adverse clinical outcome was defined as a Glasgow Outcome Scale score of 4 or less.

RESULTS

Older adults had higher rates of comorbidities, abnormal neurological and laboratory (serum white blood cell count >12,000/μL, and cerebrospinal fluid protein >100 mg/dL) findings (P < .001), abnormalities on computed tomography and magnetic resonance imaging of the head (P = .002), and adverse clinical outcomes (ACOs) (P < .001). The majority of participants (65.8%) had meningitis of unknown etiology. Bacterial meningitis was an infrequent cause of community-acquired meningitis (7.4%). Of the known causes, bacterial meningitis and West Nile virus were more common in older than younger adults; younger participants more frequently had cryptococcal and viral meningitis. On logistic regression, female sex was predictive of a poor outcome in the older participants (P = .002), whereas abnormal neurological examination (P < .001), fever (P = .01), and a cerebrospinal fluid glucose level less than 45 mg/dL (P = .002) were significant poor prognostic factors in younger participants.

CONCLUSION

Most cases of community-acquired meningitis are of unknown origin. Older adults are more likely than younger adults to have bacterial meningitis and West Nile virus infection when a cause can be identified. They also have more neurological abnormalities, laboratory and imaging abnormalities, and adverse clinical outcomes.

Acute bacterial meningitis in the intensive care unit and risk factors for adverse clinical outcomes: retrospective study

BACKGROUND

Bacterial meningitis constitutes a medical emergency. Its burden has driven from childhood to the elderly and the immunocompromised population. However, the admission of patients with bacterial meningitis to the intensive care unit (ICU) has been sparsely approached, as have the prognostic factors associated with an adverse clinical outcome.

METHODS

We performed a retrospective analysis during a 7-year period of patients older than 18 years admitted to 2 polyvalent ICUs. Clinical, demographic, and outcome data were collected to evaluate its clinical impact on the outcome of patients with acute bacterial meningitis.

RESULTS

We identified 65 patients with the diagnosis of acute bacterial meningitis (mean Acute Physiology and Chronic Health Evaluation II, 23; hospital mortality, 40%). Upon clinical presentation, their most frequent signs were fever (84%), seizures (21.5%), and a low Glasgow Coma Scale (GCS) score (GCS<8; 58.4%). Fifty-five patients (85%) required organ support. A definite microbiological diagnosis was achieved in 45 patients. An adverse clinical outcome was noted in 46 patients (71%). These patients were older (P=.005), had higher Physiology and Chronic Health Evaluation II score (P=.022), and had lower GCS (P=.022). In the multivariate analysis, older age (per year; adjusted odds ratio [aOR], 1.059) was associated with an adverse outcome, whereas a higher GCS (per point; aOR, 0.826) and presence of fever upon admission (aOR, 0.142) increase the chance of a good recovery.

CONCLUSIONS

Patients with acute bacterial meningitis admitted to ICU had substantial morbidity and mortality. Those with low GCS or absence of fever have a particularly high risk of an adverse outcome.

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.

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.