Bacterial meningitis in aging adults

Clinical features, etiologies, and outcomes of central nervous system infections in intensive care: A multicentric retrospective study in a large Brazilian metropolitan area

PURPOSE

The goal of this study was to investigate severe central nervous system infections (CNSI) in adults admitted to the intensive care unit (ICU). We analyzed the clinical presentation, causes, and outcomes of these infections, while also identifying factors linked to higher in-hospital mortality rates.

MATERIALS AND METHODS

We conducted a retrospective multicenter study in Rio de Janeiro, Brazil, from 2012 to 2019. Using a prediction tool, we selected ICU patients suspected of having CNSI and reviewed their medical records. Multivariate analyses identified variables associated with in-hospital mortality.

RESULTS

In a cohort of 451 CNSI patients, 69 (15.3%) died after a median 11-day hospitalization (5-25 IQR). The distribution of cases was as follows: 29 (6.4%) had brain abscess, 161 (35.7%) had encephalitis, and 261 (57.8%) had meningitis. Characteristics: median age 41 years (27-53 IQR), 260 (58%) male, and 77 (17%) HIV positive. The independent mortality predictors for encephalitis were AIDS (OR = 4.3, p = 0.01), ECOG functional capacity limitation (OR = 4.0, p < 0.01), ICU admission from ward (OR = 4.0, p < 0.01), mechanical ventilation ≥10 days (OR = 6.1, p = 0.04), SAPS 3 ≥ 55 points (OR = 3.2, p = 0.02). Meningitis: Age > 60 years (OR = 234.2, p = 0.04), delay >3 days for treatment (OR = 2.9, p = 0.04), mechanical ventilation ≥10 days (OR = 254.3, p = 0.04), SOFA >3 points (OR = 2.7, p = 0.03). Brain abscess: No associated factors found in multivariate regression.

CONCLUSIONS

Patients' overall health, prompt treatment, infection severity, and prolonged respiratory support in the ICU all significantly affect in-hospital mortality rates. Additionally, the implementation of CNSI surveillance with the used prediction tool could enhance public health policies.

Association between low eosinophil count and acute bacterial infection, a prospective study in hospitalized older adults

BACKGROUND

The incidence of sepsis increases significantly with age, including a high incidence of bacterial infection in the old adults. Eosinopenia and the CIBLE score have been proposed in critically ill adults and in internal medicine wards. This study aimed to assess whether a low eosinophil count was associated with acute bacterial infection among hospitalized older adults, and to find the most efficient eosinophil count cut-off to differentiate acute bacterial infection from other inflammatory states.

METHODS

This was a prospective study from July 2020 to July 2022 in geriatric wards of the University Paul Brousse Hospital (Villejuif, France) including patients aged of 75 y/o or over suffering from fever or biological inflammation. Acute bacterial infection was assessed using biological identification and/or clinical and radiological data.

RESULTS

A total of 156 patients were included. Eighty-two (53%) patients suffered from acute bacterial infection (mean age (SD) 88.7 (5.9)). Low eosinophil count was independently associated with acute bacterial infection: OR [CI95%] 3.03 [1.04-9.37] and 6.08 [2.42-16.5] for eosinophil count 0-0.07 G/L and 0.07-0.172 G/L respectively (vs. eosinophil count > 0.172 G/L). Specificity and sensitivity for eosinophil count < 0.01 G/L and CIBLE score were 84%-49% and 72%-62%, respectively with equivalent AUCs (0.66 and 0.67).

CONCLUSION

Eosinophil count < 0.01 G/L is a simple, routinely used and inexpensive tool which can easily participate in antibiotic decisions for older adults. Further studies are needed to assess clinical benefits.

TRIAL REGISTRATION

The study was registered at Clinical trial.gov (NCT04363138-23/04/2020).

Development of pharmacophore model to identify potential DNA gyrase inhibitors

There is great concern in the medical community due to rapid increase in antibiotic resistance, causing 700,000 deaths annually worldwide. Therefore, there is paramount need to develop novel and innovative antibacterial agents active against resistant bacterial strains. DNA gyrase is a crucial enzyme in bacterial replication that is absent in eukaryotes, making it effective curative target for antibacterials. To identify potential DNA gyrase inhibitors by virtual screening of NCI database using a 3-step approach. A total of 271 compounds with known IC50 values against Escherichia coli DNA GyrA were selected to develop a pharmacophore model for dual screening approach to identify new potential hits from the NCI database. In the second step, the NCI database was also screened using in-house built NN-QSAR model. Molecular docking of common 5298 compounds screened from both methods were performed against E. coli DNA GyrA (PDB id- 6RKU), and 3004 compounds are reported to exhibit lower binding energies than ciprofloxacin (-6.77 Kcal/mol). The top three compounds (NCI371878, NCI371876 and NCI142159) reported with binding energy of -13.5, -13.19 and -13.03 Kcal/mol were further subjected to MD simulation studies for 100 ns supporting the stability of the docked complexes.

Migraine in older adults

Migraine is an evolving, and sometimes lifelong disorder. The prevalence of episodic migraine peaks among individuals aged in their late 30s, implying a tendency for the disorder to remit with increasing age thereafter, whereas chronic migraine is more likely to persist into later life. Diagnosis and treatment of migraine in older adults, defined as individuals aged 60 years or older, is rendered more complex by increasing probabilities of atypical clinical features and comorbidities, with patients' comorbidities sometimes limiting their therapeutic options. However, the changing clinical presentation of migraine over an individual's lifespan is not well characterised. The neurobiological basis of remission in older adults remains unclear, although vascular, neuronal, and hormonal changes are likely to be involved. Long-term longitudinal studies of individuals with migraine would be particularly informative, with the potential not only to suggest new research directions, but also to lead to the identification of novel therapeutic agents. Although several novel migraine medications are becoming available, their effectiveness, tolerability, and safety often remain uncertain in older adults, who have commonly been excluded from the evaluation of these agents in randomised controlled trials, or who constitute only a small proportion of study populations. There is a need to recognise these limitations in the available evidence, and the specific, and often unmet, clinical needs of older adults with migraine, not least because older adults constitute an increasing proportion of populations worldwide.

A cost-effectiveness analysis of pneumococcal conjugate vaccines in infants and herd protection in older adults in Colombia

BACKGROUND

Pneumococcal diseases have a clinical and economic impact on the population. Until this year, a 10-valent pneumococcal vaccine (PCV10) used to be applied in Colombia, which does not contain serotypes 19A, 3, and 6A, the most prevalent in the country. Therefore, we aimed to assess the cost-effectiveness of the shift to the 13-valent pneumococcal vaccine (PCV13).

RESEARCH DESIGN AND METHODS

A decision model was used for newborns in Colombia between 2022-2025 and adults over 65 years. The time horizon was life expectancy. Outcomes are Invasive Pneumococcal Diseases (IPD), Community-Acquired Pneumonia (CAP), Acute Otitis Media (AOM), their sequelae, Life Gained Years (LYGs), and herd effect in older adults.

RESULTS

PCV10 covers 4.27% of serotypes in the country, while PCV13 covers 64.4%. PCV13 would avoid in children 796 cases of IPD, 19,365 of CAP, 1,399 deaths, and generate 44,204 additional LYGs, as well as 9,101 cases of AOM, 13 cases of neuromotor disability and 428 cochlear implants versus PCV10. In older adults, PCV13 would avoid 993 cases of IPD and 17,245 of CAP, versus PCV10. PCV13 saves $51.4 million. The decision model shows robustness in the sensitivity analysis.

CONCLUSION

PCV13 is a cost-saving strategy versus PCV10 to avoid pneumococcal diseases.

Prevalence of Escherichia coli ST1193 Causing Intracranial Infection in Changsha, China

ST1193 is an emerging new virulent and resistant clone among Escherichia coli with a tendency to spread rapidly across the globe. However, the prevalence of intracranial infection-causing E. coli ST1193 is rarely reported. This study aimed at determining the prevalence of E. coli ST1193 isolates, causing intracranial infections in Changsha, central China. A total of 28 E. coli isolates were collected from the cerebrospinal fluid of patients with intracranial infection over a four-year period. All isolates were differentiated using multilocus sequence typing (MLST), and phylogenetic grouping, and tested for antibiotic resistance. MLST analysis showed 11 sequence types (ST) among the 28 E. coli isolates. The most prevalent ST was B2-ST1193 (28.6%, 8/28), followed by B2-ST131 (21.4%, 6/28) and F-ST648 (10.7%, 3/28). Of the eight ST1193 isolates, three carried CTX-M-55, and one carried CTX-M-27. All eight ST1193 isolates were resistant to Ciprofloxacin, showing gyrA1AB/parC4A mutations. Two ST1193 isolates carried the aac(6′)-Ib-cr gene. All ST1193 isolates were recovered from infants with meningitis, with a fatal outcome for one three-month-old infant. ST1193 has emerged as the predominant type of E. coli strain causing intracranial infections in Changsha, China. This study highlights the importance of implementing appropriate surveillance measures to prevent the spread of this emerging public health threat.

Acute symptomatic seizures and status epilepticus in older adults: A narrative review focusing on management and outcomes

A clear narrative of acute symptomatic seizures (ASyS) in older adults is lacking. Older adults (≥60 years) have the highest incidence of seizures of all age groups and necessitate a tailored approach. ASyS has a bimodal peak in infancy and old age (82.3–123.2/100,000/year after 65 years of age). ASyS can represent half of the new-onset seizures in older adults and can progress to acute symptomatic status epilepticus (ASySE) in 52–72% of the patients. Common etiologies for ASyS in older adults include acute stroke and metabolic disturbances. For ASySE, common etiologies are acute stroke and anoxic brain injury (ABI). Initial testing for ASyS should be consistent with the most common and urgent etiologies. A 20-min electroencephalogram (EEG) is less sensitive in older adults than in younger adults and might not help predict chronic epilepsy. The prolonged postictal phase is an additional challenge for acute management. Studies note that 30% of older adults with ASyS subsequently develop epilepsy. The risk of wrongly equating ASyS as the first seizure of epilepsy is higher in older adults due to the increased long-term challenges with chronic anti-seizure medication (ASM) treatment. Specific challenges to managing ASyS in older adults are related to their chronic comorbidities and polypharmacy. It is unclear if the prognosis of ASyS is dependent on the underlying etiology. Short-term mortality is 1.6 to 3.6 times higher than younger adults. ASySE has high short-term mortality, especially when it is secondary to acute stroke. An acute symptomatic etiology of ASySE had five times increased risk of short-term mortality compared to other types of etiology.

Meningitis caused by Capnocytophaga canimorsus in a COVID-19 patient: a rare complication of dog bites

Capnocytophaga canimorsus is a gram-negative rod that is part of the commensal microbiota of dogs' and cats' mouths. In this case, we report an 85-year-old man with COVID-19 who had his right arm bitten by a dog. His symptoms were impaired consciousness, agitation and aggressive behavior. Physical examination revealed neck stiffness and Brudzinski's sign. The cerebrospinal fluid culture was compatible with Capnocytophaga canimorsus. He required intensive care and received a 14-day prescription of meropenem. After 40 days of hospitalization, the patient was fully recovered and was discharged. This case highlights the importance of physician and microbiologist be awareness of this disease, mainly in patients with neurological symptoms after a dog or cat bite.

Intracerebral Infection with E. coli Impairs Spatial Learning and Induces Necrosis of Hippocampal Neurons in the Tg2576 Mouse Model of Alzheimer’s Disease

Background:

In patients with Alzheimer’s disease (AD), bacterial infections are often associated with a cognitive decline. Animal models of genuine acute infections with viable bacteria which induce deterioration of neurodegenerative diseases are missing.

Objective:

We assessed the effect of an intracerebral infection with E. coli in a mouse model of AD.

Methods:

13-month-old Tg2576 +/- mice and transgene negative littermates (Tg2576 -/-) received an intracerebral injection with E. coli K1 or saline followed by treatment with ceftriaxone starting 41 h post infection (p.i.) for 5 days. For 4 weeks, mice were monitored for clinical status, weight, motor functions, and neuropsychological status using the Morris water maze. ELISAs, stainings, and immunohistochemistry in brains were performed at the end of the experiment.

Results:

Mortality of the infection was approximately 20%. After 4 weeks, spatial learning of infected Tg2576 +/- mice was compromised compared to non-infected Tg2576 +/- mice (p < 0.05). E. coli infection did not influence spatial learning in Tg2576 -/- mice, or spatial memory in both Tg2576 +/- and -/- mice within 4 weeks p.i.. Necrosis of hippocampal neurons was induced in infected compared to non-infected Tg2576 +/- mice 4 weeks p.i., whereas brain concentrations of Aβ_1–40, Aβ_1–42, and phosphoTau as well as axonal damage and microglia density were not altered.

Conclusion:

Here, we proved in principle that a genuine acute bacterial infection can worsen cognitive functions of AD mice. Mouse models of subacute systemic infections are needed to develop new strategies for the treatment of bacterial infections in patients with AD in order to minimize their cognitive decline.

Burden of Serious Bacterial Infections and Multidrug-Resistant Organisms in an Adult Population of Nepal: A Comparative Analysis of Minimally Invasive Tissue Sampling Informed Mortality Surveillance of Community and Hospital Deaths

BACKGROUND

Bacterial diseases are the leading cause of mortality globally, and due to haphazard use of antibiotics, antimicrobial resistance has become an emerging threat.

METHODS

This cross-sectional observational study utilized a minimally invasive tissue sampling procedure to determine the cause of death among an adult population. Bacterial cultures (blood, cerebrospinal fluid, lung tissue) and antibiotic susceptibility were evaluated, and the results were compared between community and hospital deaths.

RESULTS

Of 100 deceased persons studied, 76 (76%) deaths occurred in the community and 24 (24%) in the hospital. At least 1 bacterial agent was cultured from 86 (86%) cases; of these, 74 (86%) had a bacterial disease attributed as the primary cause of death, with pneumonia (35, 47.3%), sepsis (33, 44.6%), and meningitis (3, 4.1%) most common. Of 154 bacterial isolates (76.6% from the community and 23.4% from the hospital) detected from 86 culture-positive cases, 26 (16.8%) were multidrug-resistant (MDR). Klebsiella species were the most common (13 of 26) MDR organisms. The odds of getting an MDR Klebsiella infection was 6-fold higher among hospital deaths compared with community deaths (95% confidence interval [CI], 1.37-26.40; P = .017) and almost 23-fold higher (CI, 2.45-213.54; P = .006) among cases with prior antibiotic use compared to those without.

CONCLUSIONS

High incidence of serious bacterial infections causing death of adults in the community, with most MDR organisms isolated from hospitalized cases, calls for robust surveillance mechanisms and infection prevention activities at the community level and evidence-driven antibiotic stewardship in healthcare settings.

Rapid Fire: Acute Brain Failure in Older Emergency Department Patients

Delirium is common in older emergency department (ED) patients. Although associated with significant morbidity and mortality, it often goes unrecognized. A consistent approach to evaluation of mental status, including use of validated tools, is key to diagnosing delirium. Identification of the precipitating event requires thorough evaluation, including detailed history, medication reconciliation, physical examination, and medical work-up, for causes of delirium. Management is aimed at identifying and treating the underlying cause. Meaningful improvements in delirium care can be achieved when prevention, identification, and management of older delirious ED patients is integrated by physicians and corresponding frameworks implemented at the health system level.

Streptococcus oralis Meningitis with Gingival Bleeding in a Patient: A Case Report and Review of the Literature

An 81-year-old man with a history of gingival bleeding presented with a fever, headache, and drowsiness. His mouth and full dentures were unsanitary. Laboratory tests revealed Streptococcus oralis meningitis caused by odontogenic bacteremia. We reviewed eight reported cases, including the present case, because S. oralis meningitis is rare. Our review indicated that S. oralis meningitis needs to be considered when encountering cases of a fever, disturbance of consciousness, and headache with episodes of possible odontogenic bacteremia.

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.

Meningococcal Meningitis: A Multicentric Hospital-based Study in Kathmandu, Nepal

Background:

The global epidemiology of meningococcal disease varies markedly by region and over time. In Nepal, information on serogroup of meningococci is not available since the 1983 serogroup A epidemic in Kathmandu.

Objective:

To provide some fundamental data on the circulating serogroups of meningococci for potential meningococcal immunization programs in Nepal.

Methods:

This cross-sectional prospective study was conducted from January 2017 to December 2018 among 387 clinically suspected meningitis cases. Cerebrospinal fluid samples were collected by lumbar puncture technique at five referral hospitals of Kathmandu and processed by conventional cultural techniques. Neisseria meningitidis was identified by colony morphology, Gram staining and oxidase test. Serogrouping of meningococci was performed by slide agglutination test. Antibiotic susceptibility testing was done by the modified Kirby Bauer disc diffusion method. The data was entered into IBM SPSS Statistics 21 software and a p-value of <0.05 was considered significant.

Results:

Thirty-two samples were positive by culture for a bacterial pathogen with 2.3% of meningococci. All except one meningococcal meningitis cases were aged below 15 years. All N.meningitidis isolates belonged to serogroup A and were susceptible to ceftriaxone, chloramphenicol, meropenem and minocycline; however, 22% isolates showed resistance to cotrimoxazole and 11% intermediate resistance to ciprofloxacin.

Conclusion:

The circulating serogroup of N. meningitidis in Kathmandu has not changed over the past 35 years. The prevalence of meningococcal meningitis in Kathmandu is low but might be underestimated due to the sole use of culture-based diagnostic methods. Detection of meningococci by alternative methods may be useful in the precise estimation of actual disease burden.

Adherence to international guidelines for the treatment of meningitis infections in Lebanon

Objectives:

To assess meningitis treatment in Lebanon’s compatibility with the Infectious Diseases Society of America (IDSA) guidelines and the effect of non-compliance on mortality.

Methods:

This is a retrospective study, conducted in 5 Lebanese hospitals, and enrolling all patients diagnosed with meningitis who presented to the involved hospitals from January 2008 to December 2016.

Results:

A total of 252 participants were enrolled in the study. Of these patients, 205 (82.7%) were diagnosed with viral meningitis and 47 (17.3%) with bacterial meningitis, which was confirmed using laboratory tests. For patients with viral meningitis, 128 (62.4%) remained on the initial prescribed antibiotics despite the negative cerebrospinal fluid (CSF) and blood culture results. For bacterial meningitis patients, 30.8% received treatment regimen incompatible with the IDSA guidelines. The most common reason for the treatment incompatibility was the definitive drug choice after the culture results (49.1%) and the least common reason was inappropriate hospital stay days (25.9%). The mortality rate was 13.5%. Having low proteins values in the CSF (odds ratio=0.095) was associated with lower mortality compared to patients with normal protein values.

Conclusion:

This study shows a high percentage of inappropriate treatment in Lebanese hospitals despite these hospitals having adopted international treatment guidelines. This inappropriate management was associated with an increasing rate of mortality and neurological complications.

Activin A increases phagocytosis of Escherichia coli K1 by primary murine microglial cells activated by toll-like receptor agonists

Background

Bacterial meningitis is associated with high mortality and long-term neurological sequelae. Increasing the phagocytic activity of microglia could improve the resistance of the CNS against infections. We studied the influence of activin A, a member of the TGF-β family with known immunoregulatory and neuroprotective effects, on the functions of microglial cells in vitro.

Methods

Primary murine microglial cells were treated with activin A (0.13 ng/ml–13 μg/ml) alone or in combination with agonists of TLR2, 4, and 9. Phagocytosis of Escherichia coli K1 as well as release of TNF-α, IL-6, CXCL1, and NO was assessed.

Results

Activin A dose-dependently enhanced the phagocytosis of Escherichia coli K1 by microglial cells activated by agonists of TLR2, 4, and 9 without further increasing NO and proinflammatory cytokine release. Cell viability of microglial cells was not affected by activin A.

Conclusions

Priming of microglial cells with activin A could increase the elimination of bacteria in bacterial CNS infections. This preventive strategy could improve the resistance of the brain to infections, particularly in elderly and immunocompromised patients.

T-cell Immunoglobulin and ITIM Domain Contributes to CD8+ T-cell Immunosenescence

Aging is associated with immune dysfunction, especially T-cell defects, which result in increased susceptibility to various diseases. Previous studies showed that T cells from aged mice express multiple inhibitory receptors, providing evidence of the relationship between T-cell exhaustion and T-cell senescence. In this study, we showed that T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), a novel co-inhibitory receptor, was upregulated in CD8+ T cells of elderly adults. Aged TIGIT+ CD8+ T cells expressed high levels of other inhibitory receptors including PD-1 and exhibited features of exhaustion such as downregulation of the key costimulatory receptor CD28, representative intrinsic transcriptional regulation, low production of cytokines, and high susceptibility to apoptosis. Importantly, their functional defects associated with aging were reversed by TIGIT knockdown. CD226 downregulation on aged TIGIT+ CD8+ T cells is likely involved in TIGIT-mediated negative immune suppression. Collectively, our findings indicated that TIGIT acts as a critical immune regulator during aging, providing a strong rationale for targeting TIGIT to improve dysfunction related to immune system aging.

Thermoregulation and age

The thermoregulatory functions may vary with age. Thermosensitivity is active in neonates and children; both heat production and heat loss effector mechanisms are functional but easily exhaustable. Proportional and lasting defense against thermal challenges is difficult, and both hypothermia and hyperthermia may easily develop. Febrile or hypothermic responses to infections or endotoxin can also develop, together with confusion. In small children febrile convulsions may be dangerous. In old age the resting body temperature may be lower than in young adults. Further, thermosensitivity decreases, the thresholds for activating skin vasomotor and evaporative responses or metabolism are shifted, and responses to thermal challenges are delayed or insufficient: both hypothermia and hyperthermia may develop easily. Infection-induced fevers are often limited or absent, or replaced by hypothermia. Various types of brain damage may induce special forms of hypothermia, hyperthermia, or severe fever. Impaired mental state often accompanies hypothermia and hyperthermia, and may occasionally be a dominant feature of infection (instead of the most commonly observed fever). Aging brings about a turning point in women's life: the menopause. The well-known influence of regular hormonal cycles on the thermoregulation of a woman of fertile age gives way to menopausal hot flushes caused by estrogen withdrawal. Not all details of this thermoregulatory anomaly are fully understood yet.

Healthcare-Associated Meningitis or Ventriculitis in Older Adults

BACKGROUND/OBJECTIVES

Healthcare-associated meningitis or ventriculitis (HCAMV) is a serious and life-threatening complication of invasive neurosurgical procedures or penetrating head trauma. Older adults are at higher risk of adverse outcomes in community-acquired meningitis but studies of HCAMV are lacking. Therefore, we perform the study to define the differences in clinical outcomes between older and younger adults with HCAMV.

DESIGN

Retrospective study.

SETTING

A large tertiary care hospital in Houston, Texas, from July 2003 to November 2014.

PARTICIPANTS

Adults with a diagnosis of HCAMV (N = 160) aged ≥65 (n = 35), aged 18-64 (n = 125).

MEASUREMENTS

Demographic characteristics, clinical presentation, laboratory results, treatments, and outcomes (Glasgow Outcome Scale).

RESULTS

Older adults had more comorbidities and CSF abnormalities [pleocytosis, high cerebrospinal fluid (CSF) protein, low CSF glucose) and were more likely to have altered mental status than younger adults (P < .05). An adverse clinical outcome was seen in 142 participants (89%) (death (n = 18, 11%), persistent vegetative state (n = 26, 16%), severe disability (n = 68, 43%), moderate disability (n = 30, 19%). There was no difference in adverse outcomes between older (97%) and younger (86%) adults (P = .13). On logistic regression analysis, abnormal neurological examination (adjusted odds ratio (aOR) = 7.13, 95% confidence interval (CI) = 2.15-23.63, P = .001) and mechanical ventilation (aOR = 11.03, 95% CI = 1.35-90.51, P = .02) were associated with adverse clinical outcomes.

CONCLUSION

Older adults with HCAMV have more comorbidities and CSF abnormalities and are more likely to have altered mental status than younger adults but have similar high rates of adverse clinical outcomes.

Early versus late diagnosis in community-acquired bacterial meningitis: a retrospective cohort study

OBJECTIVES

To examine clinical characteristics and outcome of patients with late diagnosis of community-acquired bacterial meningitis (CABM).

METHODS

We conducted a chart review of all adults with proven CABM in three centres in Denmark from 1998 through to 2014. Patients were categorized as early diagnosis of CABM immediately on admission, or late diagnosis if CABM was not listed in referral or admission records and neither lumbar puncture nor antibiotic therapy for meningitis was considered immediately on admission. We used modified Poisson regression analysis to compute adjusted relative risks with 95% CIs for predictors of late diagnosis and in-hospital mortality.

RESULTS

A total of 113/358 (32%) patients were categorized as late diagnosis demonstrating a variety of tentative diagnoses of which 81/113 (72%) were non-infectious. We observed several statistically significant baseline differences (p <0.05) in patients with late versus early diagnosis including age >65 years (56/113, 50% versus 67/245, 27%), neck stiffness (35/97, 36% versus 183/234, 78%), concomitant pneumonia (26/113, 23% versus 26/245, 11%), and meningococcal meningitis (6/113, 5% versus 52/245, 21%). These variables remained statistically significant in multivariate analysis. Moreover, late diagnosis was associated with increased in-hospital mortality (41/113, 36% versus 43/245, 18%; adjusted relative risk 1.7, 95% CI 1.2-2.5).

CONCLUSIONS

Late diagnosis of CABM was common and patients were admitted with mostly non-infectious diagnoses. Absence of neck stiffness did not rule out CABM and special attention should be given to patients with pneumonia and the elderly. Late diagnosis was associated with incorrect patient management and increased mortality.

Risk factors for community-acquired bacterial meningitis

BACKGROUND

Bacterial meningitis is a significant burden of disease and mortality in all age groups worldwide despite the development of effective conjugated vaccines. The pathogenesis of bacterial meningitis is based on complex and incompletely understood host-pathogen interactions. Some of these are pathogen-specific, while some are shared between different bacteria.

METHODS

We searched the database PubMed to identify host risk factors for bacterial meningitis caused by the pathogens Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b, because they are three most common causative bacteria beyond the neonatal period.

RESULTS

We describe a number of risk factors; including socioeconomic factors, age, genetic variation of the host and underlying medical conditions associated with increased susceptibility to invasive bacterial infections in both children and adults.

CONCLUSIONS

As conjugated vaccines are available for these infections, it is of utmost importance to identify high risk patients to be able to prevent invasive disease.

Post-craniotomy intracranial infection in patients with brain tumors: a retrospective analysis of 5723 consecutive patients

AIM

To determine the risk factors for and the incidence, outcomes, and causative pathogens of post-craniotomy intracranial infection (PCII) in patients with brain tumors.

METHODS

A retrospective study was performed of 5723 patients with brain tumors who were surgically treated between January 2012 and December 2013 in Beijing Tiantan Hospital. The patients' demographics, pathohistological diagnoses, surgical procedures, postoperative variables, causative pathogens, and outcomes were evaluated.

RESULTS

The overall incidence of PCII was 6.8%, and 82.1% of all cases were diagnosed within two weeks after the craniotomy. Postoperative administration of antibiotics reduced the incidence of PCII. Independent risk factors included clean-contaminated craniotomy, prolonged operation (> 7 h), external cerebrospinal fluid (CSF) drainage/monitoring device placement, and postoperative CSF leakage. Patients ≤ 45 years old were more susceptible to infection. Compared with supratentorial tumors, tumors located in the infratentorial or intraventricular regions were more vulnerable to PCII. Gram-positive bacteria were the most common causative pathogens isolated from the CSF samples, accounting for 82.0% of the PCII cases.

CONCLUSIONS

Risk factors for PCII can be identified early in the perioperative period. These findings raise the possibility of improving the clinical outcomes of patients with brain tumors who undergo craniotomy.

Streptococcus gallolyticus (bovis): a rare presentation of meningitis in the ED

Bacterial meningitis is a fairly common and often deadly manifestation of altered mental status in the elderly, carrying a mortality rate of greater than 20% despite antibiotic therapy. Most commonly caused by Streptococcus pneumoniae, Listeria monocytogenes, Escherichia coli, and Klebsiella pneumoniae. We present a case of meningitis caused by Streptococcus gallolyticus in an elderly, otherwise healthy woman. There have been no reports in the emergency medicine literature and only a few reports in the literature of S gallolyticus as a cause of altered mental status and meningitis, specifically of immunocompetent patients.

The Optimal Management of Acute Febrile Encephalopathy in the Aged Patient: A Systematic Review

The elderly comprise less than 13 percent of world population. Nonetheless, they represent nearly half of all hospitalized adults. Acute change in mental status from baseline is commonly seen among the elderly even when the main process does not involve the central nervous system. The term "geriatric syndrome" is used to capture those clinical conditions in older people that do not fit into discrete disease categories, including delirium, falls, frailty, dizziness, syncope, and urinary incontinence. Despite the growing number of elderly population, especially those who require hospitalization and the high burden of common infections accompanied by encephalopathy among them, there are several unresolved questions regarding the optimal management they deserve. The questions posed in this systematic review concern the need to rule out CNS infection in all elderly patients presented with fever and altered mental status in the routine management of febrile encephalopathy. In doing so, we sought to identify all potentially relevant articles using searches of web-based databases with no language restriction. Finally, we reviewed 93 research articles that were relevant to each part of our study. No prospective study was found to address how should AFE in the aged be optimally managed.

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.

Distribution of strain type and antimicrobial susceptibility of Escherichia coli isolates causing meningitis in a large urban setting in Brazil

The clinical management of meningitis caused by Escherichia coli is greatly complicated when the organism becomes resistant to broad-spectrum antibiotics. We sought to characterize the antimicrobial susceptibilities, sequence types (ST), and presence of known drug resistance genes of E. coli isolates that caused meningitis between 1996 and 2011 in Salvador, Brazil. We then compared these findings to those for E. coli isolates from community-acquired urinary tract infections (UTI) that occurred during the same time period and in the same city. We found that 19% of E. coli isolates from cases of meningitis and less than 1% of isolates from UTI were resistant to third-generation cephalosporins. The sequence types of E. coli isolates from cases of meningitis included ST131, ST69, ST405, and ST62, which were also found among isolates from UTI. Additionally, among the E. coli isolates that were resistant to third-generation cephalosporins, we found genes that encode the extended-spectrum beta-lactamases CTX-M-2, CTX-M-14, and CTX-M-15. These observations demonstrate that compared to E. coli strains isolated from cases of community-acquired UTI, those isolated from cases of meningitis are more resistant to third-generation cephalosporins, even though the same sequence types are shared between the two forms of extraintestinal infections.

What are the most important infectious diseases among those ≥65 years: a comprehensive analysis on notifiable diseases, Norway, 1993-2011

BACKGROUND

As the population ages, the burden on the healthcare system might increase and require changed public health priorities. As infections are often more severe at older age, we rank notifiable infectious diseases (ID) and describe trends of ID among the general population aged ≥65 years in Norway in order to inform public health priorities for the aging population.

METHODS

We included all eligible cases of the 58 IDs notified between 1993 and 2011 (n = 223,758; 12% ≥65 years) and determined annual notification rates as the number of notified cases divided by the number of inhabitants of the corresponding year. We ranked diseases using their average annual notification rate for 2007-2011. Trends in notification rates from 1993 onwards were determined with a non-parametric test for trend. Using notification rate ratios (NRR), we compared results in those aged ≥65 years to those aged 20-64 years.

RESULTS

Invasive pneumococcal disease was the most common ID among the population ≥65 years (notification rate 58/100,000), followed by pertussis (54/100,000) and campylobacteriosis (30/100,000). Most ID notification rates did not change over time, though the notification rate of symptomatic MRSA infections increased from 1/100,000 in 1995 (first year of notification) to 14/100,000 in 2011.Overall, fewer cases were notified among the population ≥65 years compared to 20-64 year olds (NRR = 0.73). The NRR of each of the invasive bacterial diseases and antibiotic-resistant infections were above 1.5 (i.e. more common in ≥65), while the NRR of each food- and waterborne disease, blood-borne disease/STI and (non-invasive) vaccine preventable disease was below 1.

CONCLUSIONS

Based on our results, we emphasise the importance of focusing public health efforts for those ≥65 years on preventing invasive bacterial infections. This can be achieved by increasing pneumococcal and influenza vaccine uptake, and risk communication including encouraging those aged ≥65 years and their caretakers to seek healthcare at signs of systemic infection. Furthermore, good compliance to infection control measures, screening of the at-risk population, and careful use of antibiotics may prevent further increase in antibiotic-resistant infections.

Scoping the impact of changes in population age-structure on the future burden of foodborne disease in the Netherlands, 2020-2060

A demographic shift towards a larger proportion of elderly in the Dutch population in the coming decades might change foodborne disease incidence and mortality. In the current study we focused on the age-specific changes in the occurrence of foodborne pathogens by combining age-specific demographic forecasts for 10-year periods between 2020 and 2060 with current age-specific infection probabilities for Campylobacter spp., non-typhoidal Salmonella, hepatitis A virus, acquired Toxoplasma gondii and Listeria monocytogenes. Disease incidence rates for the former three pathogens were estimated to change marginally, because increases and decreases in specific age groups cancelled out over all ages. Estimated incidence of reported cases per 100,000 for 2060 mounted to 12 (Salmonella), 51 (Campylobacter), 1.1 (hepatitis A virus) and 2.1 (Toxoplasma). For L. monocytogenes, incidence increased by 45% from 0.41 per 100,000 in 2011 to 0.60 per 100,000. Estimated mortality rates increased two-fold for Salmonella and Campylobacter to 0.5 and 0.7 per 100,000, and increased by 25% for Listeria from 0.06 to 0.08. This straightforward scoping effort does not suggest major changes in incidence and mortality for these food borne pathogens based on changes in de population age-structure as independent factor. Other factors, such as changes in health care systems, social clustering and food processing and preparation, could not be included in the estimates.

Clinical picture of meningitis in the adult patient and its relationship with age

To analyze the clinical characteristics of acute meningitis and their relationship with age in adult patients presenting to the emergency department. We retrospectively investigated consecutive adult patients admitted with a diagnosis of bacterial or viral meningitis from 2002 to 2006. Data about patient's history, symptoms and signs at presentation, etiology and clinical course were collected. To investigate the relationship of clinical presentation with age, we divided patients in four age quartiles (<30 years, between 30 and 36 years, between 37 and 56 years, >56 years). Among the 202 patients considered in the study (mean age 42.8 ± 18.7 years, range 14-90), 162 (80.2%) patients had viral and 40 (19.8%) bacterial meningitis. Specific signs, such as neck stiffness or Kernig or Brudzinski signs, were more common in the first than in the fourth quartile (73.1 vs. 45.7% P = 0.041). Conversely, altered consciousness expressed as Glasgow Coma Scale (GCS) <15 was more frequent in the fourth (80.4%) than in the first (9.6%) quartile (P < 0.001). The linear regression analysis confirmed a significant decrease of GCS with the increasing of patient's age (r = -0.69, P < 0.001). At multivariate analysis, aging was associated with altered level of consciousness (OR 16.7, P < 0.001) independent of viral or bacterial etiology of the presence of comorbidities and of clinical severity (presence of severe sepsis or septic shock). Meningitis presentation largely differs with aging in adult patients. Level of consciousness is frequently altered in the older patients, when other specific signs become more rare, independent of etiology, comorbidities and clinical severity.

Epidemiology, diagnosis, and antimicrobial treatment of acute bacterial meningitis

The epidemiology of bacterial meningitis has changed as a result of the widespread use of conjugate vaccines and preventive antimicrobial treatment of pregnant women. Given the significant morbidity and mortality associated with bacterial meningitis, accurate information is necessary regarding the important etiological agents and populations at risk to ascertain public health measures and ensure appropriate management. In this review, we describe the changing epidemiology of bacterial meningitis in the United States and throughout the world by reviewing the global changes in etiological agents followed by specific microorganism data on the impact of the development and widespread use of conjugate vaccines. We provide recommendations for empirical antimicrobial and adjunctive treatments for clinical subgroups and review available laboratory methods in making the etiological diagnosis of bacterial meningitis. Finally, we summarize risk factors, clinical features, and microbiological diagnostics for the specific bacteria causing this disease.

Community acquired bacterial meningitis in Cuba: a follow up of a decade

Background

Community acquired Bacterial Meningitis (BM) remains a serious threat to global health. Cuban surveillance system for BM allowed to characterize the main epidemiological features of this group of diseases, as well as to assess the association of some variables with mortality. Results of the BM surveillance in Cuba are presented in this paper.

Methods

A follow up of BM cases reported to the Institute "Pedro Kourí" by the National Bacterial Meningitis Surveillance System from 1998 to 2007 was completed. Incidence and case-fatality rate (CFR) were calculated. Univariate analysis and logistic regression were used to elucidate associated factors to mortality comparing death versus survival. Relative Risk (RR) or odds ratio and its 95% confidence interval (CI 95%) were estimated, using either a Chi-squared Test or Fisher's Exact Test as appropriate. A Holt-Winters model was used to assess seasonality.

Results

4 798 cases of BM (4.3 per 100 000 population) were reported, with a decreasing trend of the incidence. Highest incidence was observed in infants and elderly. Overall CFR reached 24.1% affecting mostly older adults. S. pneumoniae (23.6%), N. meningitidis(8.2%) and H. influenzaetype b (6.0%) were the main causative agents. Males predominate in the incidence. Highest incidence and CFR were mainly clustered in the centre of the island. The univariate analysis did not show association between delayed medical consultation (RR = 1.20; CI = 1.07-1.35) or delayed hospitalization (RR = 0.98; CI = 0.87-1.11) and the fatal outcome. Logistic regression model showed association of categories housewife, pensioned, imprisoned, unemployed, S. peumoniae and other bacteria with mortality. Seasonality during September, January and March was observed.

Conclusions

The results of the National Program for Control and Prevention of the Neurological Infectious Syndrome evidenced a reduction of the BM incidence, but not the CFR. Multivariate analysis identified an association of mortality with some societal groups as well as with S. peumoniae.

Depressive-like-behavior and proinflamatory interleukine levels in the brain of rats submitted to pneumococcal meningitis

Bacterial meningitis due to Streptococcus pneumoniae is associated with a significant mortality rate and persisting neurologic sequelae including sensorymotor deficits, seizures, and impairments of learning and memory. The presence of proliferating bacteria within the subarachnoid and ventricular space compartments triggers an intense inflammatory host response. Proinflammatory mediators released in the process include tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and all of which have been shown to contribute to the development of brain injury in bacterial meningitis. The animals underwent a magna cistern tap receiving either 10muL sterile saline as a placebo or an equivalent volume of a S. pneumoniae suspension at the concentration 5x10(9)cfu/mL. Ten days after induction we evaluated depressive-like behavior by using the forced swimming test and verified the levels of the TNF-alpha, IL-1beta, IL-6 and CINC-1 in the brain of rats induced to pneumococcal meningitis. In the forced swimming test we observed a significant increase in the immobility time in the meningitis group compared to the sham group (p<0.05). The TNFlevels were found increased in the prefrontal cortex (p<0.05, F=4.921), but not hippocampus. The IL-6, CINC-1 and IL-1beta levels presented no alteration in both prefrontal cortex and hippocampus 10 days after meningitis induction by S. pneumoniae. These findings suggest that the meningitis model could be a good research tool for the study of the biological mechanisms involved in the behavioral alterations secondary to pneumococcal meningitis.

Tumor necrosis factor alpha (TNF-alpha) levels in the brain and cerebrospinal fluid after meningitis induced by Streptococcus pneumoniae

Bacterial meningitis due to Streptococcus pneumoniae is associated with a significant mortality rate and persisting neurologic sequelae including sensory-motor deficits, seizures, and impairments of learning and memory. The presence of proliferating bacteria within the subarachnoid and ventricular space compartments triggers an intense inflammatory host response at killing the invading microorganism. Proinflammatory mediators released in the process include tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1beta, IL-6. TNF-alpha have several effects, including cytotoxicity, antiviral activity, transcription factor activation, and immune response regulation. Thus, the aim of this study was to verify the levels of the TNF-alpha after pneumococcal meningitis in male Wistar rats. The animals underwent a magna cistern tap receiving either 10 microL sterile saline as a placebo or an equivalent volume of a S. pneumoniae suspension at the concentration 5 x 10(9)cfu/mL. The animals were killed at 0, 6, 12, 24, 48 and 96 h after induction. The brain was removed and hippocampus, cortex, prefrontal and cerebrospinal fluid (CSF) were isolated and used for the determination of TNF-alpha levels. We found an increase in TNF-alpha levels at 6h after induction of the meningitis in the hippocampus (p<0.01), frontal cortex (p<0.05), and cerebrospinal fluid (p<0.001).There was no alteration in the cortex. Our data suggest that TNF-alpha is involved in the pathophysiology of the pneumococcal meningitis and could be investigated as a putative biomarker for brain damage in the first hours.

[Sensitivity and specificity of clinical signs in adults]

Clinical diagnosis of acute bacterial meningitis may be delayed, either because off lack of sensitivity of clinical signs, or because of a poor vital prognosis; but over diagnosing is also frequent, leading to useless, expensive, and potentially dangerous hospitalizations. We conducted a comprehensive review of English and French literature from 1997 to 2007 by searching MEDLINE to review the accuracy of clinical examination for the diagnosis of meningitis. Additional references were identified by reviewing reference lists of articles back to 1993. We used the keywords "meningitis", "meningitis and clinical features", "cerebrospinal fluid (CSF) pleocytosis", "headache and fever", "Kernig sign", "Brudzinski sign", and "neck stiffness". We excluded nosocomial meningitis. Sensitivity for clinical signs such as headache, vomiting, or fever was low, generally less than 30%, neck stiffness could reach 45%, but the absence of two signs among fever, headache, neck stiffness, and altered mental status eliminated meningitis with a negative predictive value of 95%. Given the seriousness of bacterial meningitis, clinicians perform lumbar puncture (or brain imaging) too often, especially in high-risk patients. Further prospective clinical research is needed to improve the accuracy of bacterial meningitis clinical diagnosis.

Management of severe community-acquired septic meningitis in adults: from emergency department to intensive care unit

BACKGROUND/PURPOSE

To study the clinical features, diagnostic processes, timing of antibiotic administration and outcomes of patients with severe community-acquired septic meningitis at an emergency department (ED), who required intensive care unit (ICU) admission.

METHODS

From January 1993 to December 2005, the medical records of patients admitted to the ICU with a diagnosis of community-acquired septic meningitis were reviewed. The clinical characteristics, including causative pathogens, treatment course, and outcomes were collected and analyzed.

RESULTS

A total of 40 patients were included, with an overall in-hospital mortality rate of 77.5%. The most common pathogen was Klebsiella pneumoniae (n=20, 50%), followed by Streptococcus pneumoniae (n=6, 15%), and Cryptococcus neoformans (n=5, 12.5%). There was a mean duration of 8.9 hours between ED arrival and initiation of antibiotic therapy. Effective antibiotics were administered for a mean period of 23.8 hours after arrival. Time delay from ED arrival to ICU admission was correlated with time delay of effective antibiotics administration, head computed tomography, and cerebrospinal fluid study (r=0.32, 0.47, and 0.53, respectively; p=0.05, 0.006, and 0.001, respectively). Earlier ICU admission was demonstrated in survivors as compared with those who died (11.1 vs. 38.0 hours, p=0.01).

CONCLUSION

Severe septic meningitis remains a disease with high mortality and morbidity. Expeditious diagnostic processes with early appropriate antibiotic treatment and ICU admission at the ED are important in improving the quality of care and patient outcome.

Community-acquired bacterial meningitis in elderly patients: experience over 30 years

Clinical characteristics, etiologies, evolution, and prognostic factors of community-acquired bacterial meningitis in elderly patients are not well known. To improve this knowledge, all episodes of community-acquired bacterial meningitis were prospectively recorded and cases occurring in patients >or=65 years old were selected. During the period 1977-2006, 675 episodes in adults (aged >or=18 yr) were recorded, with 185 (27%) in patients aged >or=65 years old; 76 were male and 109 were female, with a mean age of 73 +/- 6 years (range, 65-93 yr). Causative microorganisms were Streptococcus pneumoniae 74, Neisseria meningitidis 49, Listeria monocytogenes 17, other streptococcal 9, Escherichia coli 6, Haemophilus influenzae 4, Klebsiella pneumoniae and Staphylococcus aureus 2 each, Capnocytophaga canimorsus and Enterococcus faecalis 1 each, and unknown in 20. On admission 91% had had fever, 32% were in a coma (Glasgow Coma Scale <or=8), 9% presented with seizures, and 8% with shock. Thirty patients (16%) presented with seizures during therapy. Mortality was 58/185 (31%). Compared with patients aged 18-65 years, there were significant differences among older patients (aged >or=65 yr), who showed a higher frequency of diabetes and malignancy as underlying disease; pneumonia, otitis, and pericranial fistula as predisposing factors; and S. pneumoniae and L. monocytogenes as etiology. There were also differences in clinical presentation, complications, sequelae, and mortality. Factors independently related with mortality were age, pneumonia as a predisposing factor, coma on admission, and heart failure and seizures after therapy. Dexamethasone therapy was a protective factor. In conclusion, bacterial meningitis in elderly patients is associated with greater diagnostic difficulties and neurologic severity and more complications, as well as with increased mortality. Antiseizure prophylaxis might be useful in these patients.

A predictive model of the economic effects of an influenza vaccine adjuvant for the older adult (age 65 and over) population

Immunosenescence decreases influenza vaccine efficacy in older adults (age 65 and over). Strategies such as vaccine adjuvants are being developed to overcome immunosenescence. Our computer simulation model represented the decision to give an older adult either standard influenza vaccine or adjuvanted influenza vaccine and found the adjuvanted vaccine to be dominant in many scenarios, resulting in lowered cost and greater effectiveness. An adjuvanted vaccine that is 100% effective in overcoming immunosenescence remained dominant until its cost exceeded the standard vaccine cost by $65. In a single influenza season, the adjuvant would prevent 496,533 influenza cases, 171,981 hospitalizations, and 70,429 deaths.