Community-acquired bacterial meningitis in adults with cancer or a history of cancer

[Vaccination of children and adolescents treated for acute leukemia, excluding HSCT recipients: Recommendations of the French Society for Childhood and Adolescent Cancer and Leukemia (SFCE)]

Children and adolescents who are being treated or have been treated for acute leukemia have a secondary immunodeficiency linked to chemotherapy, resulting in an increased risk of infections. Some of which can be prevented by vaccination but its effectiveness is not optimal during chemotherapy. Upon cessation of chemotherapy, the time required for immune reconstitution varies from three months to more than a year, depending on lymphocyte subpopulations, the patient's age, and the intensity of the treatment received. Although they may have regained their immune functions, studies show that most patients have lost part of their vaccine-induced protection post-chemotherapy and require booster doses of vaccines. Most practitioners agree on the importance of vaccinating or revaccinating these children, but practices are heterogeneous among pediatric hematologist-oncologists in France. Based on a practice study and a recent review of the literature, this work aims to propose new French recommendations for the vaccination strategy to be adopted for children and adolescents treated or recently treated for acute leukemia, excluding allogeneic transplant recipients, in 2024. These recommendations specifically include the vaccination protocols for human papillomavirus and meningococcal infections but do not address the COVID-19 vaccination, as its guidelines are subject to rapid changes.

Community-Acquired Meningitis Complicated With Pyogenic Ventriculitis and Hydrocephalus in a Patient With Haematological Malignancy: A Case Report and Literature Review

Meningitis, an infection of the meninges of the central nervous system (CNS), can advance quickly and carries a mortality rate reaching 30% among affected patients. It may become complicated by conditions such as hydrocephalus, ventriculitis, and cerebral abscess. Here, we describe a case of meningitis that was complicated by pyogenic ventriculitis and hydrocephalus in a patient with diffuse large B-cell lymphoma (DLBCL) who underwent chemotherapy and radiotherapy. The patient presented with acute change in mental status and high-grade fever, with few episodes of non-bloody vomiting. Blood culture and cerebrospinal fluid (CSF) culture grew Streptococcus pneumoniae, which was sensitive to ceftriaxone. CT scan of the head showed ventriculomegaly, pansinusitis, and a large left mastoid effusion. MRI of the brain showed layering in ventricles, hydrocephalus, and dural enhancement consistent with pachymeningitis. She was treated with ceftriaxone for 21 days with a meaningful outcome. She was discharged home with near-baseline mental capacity for further physical therapy.

Adjunctive dexamethasone treatment in adults with listeria monocytogenes meningitis: a prospective nationwide cohort study

Background

A French cohort study described a detrimental effect of adjunctive dexamethasone treatment in listeria meningitis. Based on these results guidelines recommend not to use dexamethasone if L. monocytogenes is suspected or stop dexamethasone when the pathogen is detected. We studied clinical characteristics, treatment regimens and outcome of adults with Listeria monocytogenes meningitis in a nationwide cohort study on bacterial meningitis.

Methods

We prospectively assessed adults with community-acquired L. monocytogenes meningitis in the Netherlands between Jan 1, 2006, and July 1, 2022. We identified independent predictors for an unfavourable outcome (Glasgow Outcome Scale score 1 to 4) and mortality by logistic regression.

Findings

162 out of 2664 episodes (6%) of community-acquired bacterial meningitis episode were caused by L. monocytogenes in 162 patients. Adjunctive dexamethasone 10 mg QID was started with the first dose of antibiotics in 93 of 161 patients (58%) and continued for the full four days in 83 (52%) patients. Different doses, duration or timing of dexamethasone were recorded in 11 patients (7%) and 57 patients (35%) did not receive dexamethasone. The case fatality rate was 51 of 162 (31%) and an unfavourable outcome occurred in 91 of 162 patients (56%). Age and the standard regimen of adjunctive dexamethasone were independent predictors for an unfavourable outcome and mortality. The adjusted odds ratio of dexamethasone treatment for unfavourable outcome was 0.40 (95% confidence interval 0.19-0.81).

Interpretation

Adjunctive dexamethasone is associated with an improved outcome in patients with L. monocytogenes meningitis and should not be withheld if L. monocytogenes is suspected or detected as causative pathogen.

Funding

European Research Council and Netherlands Organisation for Health Research and Development.

Human Listeriosis

Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that can cause severe invasive infections upon ingestion with contaminated food. Clinically, listerial disease, or listeriosis, most often presents as bacteremia, meningitis or meningoencephalitis, and pregnancy-associated infections manifesting as miscarriage or neonatal sepsis. Invasive listeriosis is life-threatening and a main cause of foodborne illness leading to hospital admissions in Western countries. Sources of contamination can be identified through international surveillance systems for foodborne bacteria and strains' genetic data sharing. Large-scale whole genome studies have increased our knowledge on the diversity and evolution of L. monocytogenes, while recent pathophysiological investigations have improved our mechanistic understanding of listeriosis. In this article, we present an overview of human listeriosis with particular focus on relevant features of the causative bacterium, epidemiology, risk groups, pathogenesis, clinical manifestations, and treatment and prevention.

Characteristics and risk factors of bacterial meningitis caused by Streptococcus agalactiae, Streptococcus pneumoniae or Escherichia coli in Guangzhou China from 2015 to 2022

Introduction

Bacterial meningitis (BM) is an infectious disease with high morbidity and mortality rates in children. Although vaccination has improved prevention of BM, this severe disease continues to cause considerable harm to children across the globe. Several risk factors have been identified for BM, including immune status, age, and sex. However, additional patient and disease information is required in order to better understand the local characteristics, epidemiology and risk factors of BM.

Methods

Here, we collected information from 252 children with BM in the Guangzhou Women and Children Medical Centre medical record database infected with Streptococcus agalactiae, Streptococcus pneumoniae, or Escherichia coli between May 2015 and May 2022.

Results

The three pathogen infected BM cased showed distinct trends during the period, and distribution of three BM pathogens across age groups varied significantly. We reviewed the antimicrobial resistance patterns for each of the pathogens which may direct drug use in BM. Finally, we found blood WBC was a protective factor, while glucose levels in the CFS was risk factor, for the length of hospitalization.

Discussion

Collectively, this study provides multi-parameter characteristics of BM, and potentially guide the drug use.

BACTERIAL MENINGITIS IN PATIENTS WITH MULTIPLE MYELOMA: A PROSPECTIVE NATIONWIDE COHORT STUDY AND REVIEW OF THE LITERATURE

OBJECTIVE

To study the clinical features of bacterial meningitis in myeloma patients.

METHODS

We analyzed myeloma patients included in a nationwide cohort of patients >16 years old with community-acquired bacterial meningitis in the Netherlands between 2006 and 2018. Subsequently, we reviewed the literature for articles reporting myeloma patients with bacterial meningitis.

RESULTS

A total of 27 of 2306 (1.6%) episodes of bacterial meningitis occurred in myeloma patients. Six of 27 (22%) patients received stem cell transplantation. CSF showed a median leukocyte count of 172/µL and 12 (46%) of 26 patients had a CSF leukocyte count <100/µL. Streptococcus pneumoniae was the causative pathogen in 25 (93%) patients. Fourteen (52%) patients had unfavorable outcome of whom 10 (37%) died. Ninety-one myeloma patients with bacterial meningitis were described in the literature. The most common pathogen in these patients was S. pneumoniae (35 of 48; 73%) and four (20%) of 20 cases died.

CONCLUSION

Bacterial meningitis in patients with multiple myeloma is a severe disease with high rates of unfavorable outcome. Patients often present with a low CSF leukocyte count compared to bacterial meningitis in patients without multiple myeloma. Physicians should have a low threshold to perform a lumbar puncture in myeloma patients and start antibiotic treatment pending CSF chemistry and culture results.

BACTERIAL MENINGITIS PRESENTING WITH A NORMAL CEREBROSPINAL FLUID LEUKOCYTE COUNT

OBJECTIVES

We describe clinical characteristics and outcome of adults with bacterial meningitis presenting with a normal CSF leukocyte count.

METHODS

We studied community-acquired bacterial meningitis with a normal CSF leukocyte count (≤ 5 per mm³) in adults from a prospective nationwide cohort study.

RESULTS

From 2006 through 2020, 39 of 2,357 (2%) episodes presented with a normal CSF leukocyte count. Immunocompromising conditions were present in 19 of 39 patients (49%), compared to 690 of 2303 (30%) in patients with elevated leukocytes (P=0.02). The triad of fever, neck stiffness, and altered consciousness was present in 6 of 34 patients (18%). CSF protein was abnormal in 25 of 37 patients (68%). We identified 3 clinical subgroups: those with severe pneumococcal meningitis (20 patients [51%]), with mainly sepsis (8 [21%]), and a miscellaneous group (11 [28%]). All patients with severe pneumococcal meningitis presented with high CSF protein levels and 18 of 19 (95%) had bacteria in the CSF Gram stain. Outcome was unfavorable in 23 of 39 (59%) patients and 12 (31%) died.

CONCLUSION

Patients with bacterial meningitis may present with normal CSF leukocyte counts. In these patients, CSF protein levels and Gram staining are important diagnostic parameters.

Synchronous pulmonary adenocarcinoma and primary leptomeningeal large B-cell lymphoma-Diagnostic challenge in cerebrospinal fluid: A brief report

Lung cancer is one of the most common causes of cancer-related deaths worldwide. During or after the treatment of lung cancer, patients might develop another malignant neoplasm. To our knowledge, synchronous pulmonary adenocarcinoma and leptomeningeal large B-cell lymphoma have not been reported in the literature. Herein, we report the first case of synchronous pulmonary adenocarcinoma and primary leptomeningeal lymphoma, which is challenging in cytological diagnosis using cerebrospinal fluid (CSF). Knowledge of this rare situation by cytopathologists might avoid misdiagnosis or erroneous tumor classification during the cytological diagnosis of CSF in the future.

Central Nervous System Infections in Immunocompromised Patients

PURPOSE OF REVIEW

This article reviews current epidemiologic trends, clinical presentations, and diagnostic strategies for central nervous system (CNS) infections in human immunodeficiency virus-negative (HIV) patients immunocompromised by their underlying disease or by receipt of immunosuppressive or immunomodulating therapies. Three patient groups are considered: (1) cancer patients; (2) hematopoietic or solid organ transplantation recipients; and (3) patients with autoimmune or inflammatory conditions requiring therapies that alter the host immune response.

RECENT FINDINGS

Clinical presentations, associated neuroimaging, and cerebrospinal fluid (CSF) abnormalities differ between immunocompromised and immunocompetent patients. Infections can trigger the emergence of neurotropic antibodies or inflammatory conditions due to treatment with cancer immunotherapies. Unbiased metagenomic assays to identify obscure pathogens help clinicians navigate the increasing range of conditions affecting the growing population of patients with altered immunity. Awareness of clinical presentations and disease and drug-specific risks is important for early diagnosis and intervention in these often life-threatening infections and their noninfectious mimes.

Community-acquired bacterial meningitis in adults: emergency department management protocol

Acute bacterial meningitis (ABM) is a rare but disabling infectious condition that requires a performant multidisciplinary management approach. Between 70 and 90 adult patients are diagnosed with community-acquired ABM in Belgium annually, and reported case fatality rates range from 17 to 40%. The currently available guidelines provide evidence-based guidance on how to manage this disease. However, these guidelines do not translate the evidence to the daily practice at the emergency department in a Belgian healthcare context. We created a taskforce in University Hospitals Leuven consisting of experts with complementary expertise in managing this disease: neurology, neurosurgery, intensive care medicine, microbiology and infectious diseases. The taskforce agreed upon a flowchart containing seven management steps encompassing all relevant phases in emergency ABM management. In addition to the focus on timely and adequate initiation of antimicrobial treatment, the flowchart and protocol also provide guidance on practical hurdles such as how to assess the safety of performing a lumbar puncture and when to refer patients to the intensive care department. This protocol was implemented in University Hospitals Leuven and fosters inter-disciplinary coordination of ABM care.

Listeria monocytogenes infections: Analysis of 41 patients

OBJECTIVE

We describe and analyze Listeria-related demographics and clinical features to determine the predisposing conditions for severe infections.

METHODS

We performed a retrospective study using positive isolation of Listeria monocytogenes from blood, cerebrospinal fluid, and other organic fluids. Electronic health records were used to determine the epidemiological and clinical features of infections caused by L. monocytogenes. Mortality and sepsis were considered dependent variables in the statistical analyses.

RESULTS

We included 41 patients in an observation period of 15 years (2003-2018), with an annual incidence rate of 1.3 cases per 100,000 population. Three main population profiles were identified: newborns, pregnant women, and other adults (17.1%, 12.2%, and 82.9%, respectively). Neuroinvasive infection was present in 17 patients (41.5%). In both univariate and multivariate analyses, neurological infections, whether meningoencephalitis, rhombencephalitis, or brain abscesses, were the main risk factors for severe forms of Listeria-related infections (odds ratio 1.8, 95% CI 1.52-2.14, p=0.01). Malignancies, whether solid tumors or hematological neoplasms, immunosuppression, and chronic diseases were not related to either mortality or severe clinical syndromes.

CONCLUSION

Infections caused by L. monocytogenes were uncommon but could cause severe sepsis and mortality, especially in susceptible populations. Our study focused on neurological involvement and severe invasive forms of listeriosis. Neuroinvasive forms were the most important risk factors for severe illness but not for mortality.

Lumbar Puncture Performed Promptly or After Neuroimaging in Acute Bacterial Meningitis in Adults: A Prospective National Cohort Study Evaluating Different Guidelines

Background

Early treatment is pivotal for favorable outcome in acute bacterial meningitis (ABM). Lumbar puncture (LP) is the diagnostic key. The aim was to evaluate the effect on outcome of adherence to European Society of Clinical Microbiology and Infectious Diseases (ESCMID), Infectious Diseases Society of America (IDSA), and Swedish guidelines regarding neuroimaging before LP.

Methods

The cohort comprised 815 adult ABM patients in Sweden registered prospectively between 2008 and 2015. Primary endpoint was in-hospital mortality and secondary endpoint was favorable outcome at 2-6 months of follow-up.

Results

Indications for neuroimaging before LP existed in 7%, 32%, and 65% according to Swedish, ESCMID, and IDSA guidelines, respectively. The adjusted odds ratio (aOR) was 0.48 (95% confidence interval [CI], .26-.89) for mortality and 1.52 (95% CI, 1.08-2.12) for favorable outcome if Swedish guidelines were followed. ESCMID guideline adherence resulted in aOR of 0.68 (95% CI, .38-1.23) for mortality and 1.05 (95% CI, .75-1.47) for favorable outcome. Following IDSA recommendations resulted in aOR of 1.09 (95% CI, .61-1.95) for mortality and 0.59 (95% CI, .42-.82) for favorable outcome. Performing prompt vs neuroimaging-preceded LP was associated with aOR of 0.38 (95% CI, .18-.77) for mortality and 2.11 (95% CI, 1.47-3.00) for favorable outcome. The beneficial effect of prompt LP was observed regardless of mental status and immunosuppression.

Conclusions

Adherence to Swedish guidelines in ABM is associated with decreased mortality and increased favorable outcome in contrast to adherence to ESCMID or IDSA recommendations. Our findings support that impaired mental status and immunocompromised state should not be considered indications for neuroimaging before LP in patients with suspected ABM.

Acute Bacterial Meningitis

PURPOSE OF REVIEW

While acute bacterial meningitis is becoming less common in developed countries because of the widespread use of vaccines against Streptococcus pneumoniae, Neisseria meningitides, and Haemophilus influenzae, bacterial meningitis still occurs worldwide, with peak incidence in young children and the elderly. Bacterial meningitis is usually lethal unless appropriate antibiotics that cross the blood-brain barrier are given. Clinical suspicion of bacterial meningitis begins when patients present with the abrupt onset of fever, headache, and meningismus.

RECENT FINDINGS

New technologies are being developed for more rapid identification of the bacterial species causing meningitis. When appropriate, administration of adjunctive dexamethasone with the antibiotics often lessens neurologic sequelae in survivors, which may include aphasia, ataxia, paresis, hearing loss, and cognitive impairment.

SUMMARY

Confirmation of the diagnosis of bacterial meningitis comes mainly from examination and culture of CSF obtained from a lumbar puncture. Typically, the CSF shows an elevated neutrophil count, elevated protein, depressed glucose, positive Gram stain, and growth of the bacteria on appropriate culture media. Antibiotic sensitivities of the bacteria determine the appropriate antibiotics, although an educated guess of the best antibiotics to be given promptly must be made until the antibiotic sensitivities return, usually in a few days.

Histopathology of Listeria Meningitis

Listeria monocytogenes meningitis is the third most common cause of bacterial meningitis in adults and has high mortality and morbidity rates. We describe the clinical course and score brain pathology of 5 patients who died of listeria meningitis. All patients were immunocompromised and ages ranged between 48 and 76 years. Three cases were confirmed by cerebrospinal fluid culture; one was confirmed by brain culture; and one diagnosis was based on a positive blood culture and neuropathological findings. Mild inflammation of meningeal arteries was found in 3 of 5 cases (60%). Moderate/severe ventriculitis was seen in 4 of 4 cases (100%), abscesses in 3 of 4 cases (75%), mild vascular inflammation in 4 of 5 cases (80%), mild/moderate hemorrhage in 2 of 4 cases (50%), mild/moderate thrombosis of meningeal artery in 3 of 5 cases (60%), and 1 case (25%) showed a moderate infarct. The inflammatory cells present in the meninges were characterized by a mix of monocytes, macrophages, and neutrophils and removal of apoptotic inflammatory cells by macrophages (efferocytosis). Gram stain showed intra- and extracellular presence of rod-shaped bacteria in 3 cases. Pathological examination was characterized by moderate to severe ventriculitis, abscesses and abundant efferocytosis which has been suggested to be exploited by L. monocytogenes for cell-to-cell spread.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Central Nervous System Infections Complicating Immunosuppression and Transplantation

PURPOSE OF REVIEW

This article reviews infections associated with cancer treatments and immunosuppressive/immunomodulatory therapies used in both neoplastic and non-neoplastic conditions, including hematopoietic cell transplantation and solid organ transplantation. It provides a clinical approach to the most commonly affected patient groups based on clinicoanatomic presentation and disease-specific risks resulting from immune deficits and drugs received.

RECENT FINDINGS

The clinical presentations, associated neuroimaging findings, and CSF abnormalities of patients with central nervous system infections who are immunocompromised may differ from those of patients with central nervous system infections who are immunocompetent and may be confused with noninfectious processes. Triggering of brain autoimmunity with emergence of neurotropic antibodies has emerged as a recognized parainfectious complication. New unbiased metagenomic assays to identify obscure pathogens help clinicians navigate the increasing range of conditions affecting the growing population of patients with altered immunity.

SUMMARY

Despite evidence-based prophylactic regimens and organism-specific antimicrobials, central nervous system infections continue to cause significant morbidity and mortality in an increasing range of patients who are immunocompromised by their conditions and therapies. Multiple new drugs put patients at risk for progressive multifocal leukoencephalopathy, which has numerous imaging and clinical manifestations; patients at risk include those with multiple sclerosis, for whom infection risk is becoming one of the most important factors in therapeutic decision making. Efficient, early diagnosis is essential to improve outcomes in these often-devastating diseases.

Update on community-acquired bacterial meningitis: guidance and challenges

BACKGROUND

The existing heterogeneity in diagnostic work-up and treatment strategies in bacterial meningitis was the incentive to develop a European evidence-based guideline, which was published in 2016 by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group on Infections of the Brain (ESGIB).

AIMS

To summarize salient features of the guideline, identify recent developments and challenges currently faced.

SOURCES

The ESCMID guideline, ongoing trial registries.

CONTENT

Epidemiology, clinical symptoms, diagnostic work-up and therapy strategies of acute bacterial meningitis.

IMPLICATIONS

The incidence of bacterial meningitis has decreased following pneumococcal and meningococcal conjugate vaccine introduction. In the diagnosis of bacterial meningitis the clinical characteristics and laboratory parameters are of limited diagnostic accuracy and therefore cerebrospinal fluid analysis remains the principal contributor to the final diagnosis. The ESCMID guideline advises to start empiric treatment within one hour of arrival in all suspected meningitis cases, and choice of antibiotics needs to be differentiated according to the patient's age, risk factors, and local resistance rates of pneumococci. Dexamethasone is the only proven adjunctive treatment and should be started together with the antibiotics. The follow-up of surviving patients should include evaluation for hearing loss and pneumococcal vaccination to prevent recurrences. Future perspectives include further development and implementation of vaccines, and new treatments aimed at further reducing the inflammatory response. Studies on implementation of the new guideline should determine adherence and evaluate whether improved prognosis can be achieved by following protocolled management 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.

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.

Sex-based differences in adults with community-acquired bacterial meningitis: a prospective cohort study

OBJECTIVES

To investigate sex-based differences in clinical features, causative pathogens, outcome and treatment of adult community-acquired meningitis.

METHODS

From January 2006 to July 2014, we prospectively investigated sex-based differences in clinical features, causative pathogens, outcome and treatment of adult community-acquired meningitis in a nationwide cohort study in the Netherlands. Sex was analysed along with known predictors of unfavourable outcome using logistic regression.

RESULTS

We evaluated 1412 episodes of meningitis, 707 (50%) in men. Men more often presented with a history of remote head injury (41/667 (6%) versus 14/658 (2%) women, p 0.0002) or alcoholism (61/652 (9%) versus 21/660 (3%) women, p <0.0001). Neck stiffness was less common in men (453/651 (70%) versus 524/671 (78%) women, p 0.0004). Despite greater illness severity, women were less likely to receive treatment in an intensive care unit (odds ratio (OR) 0.72, 95% CI 0.58-0.89, p 0.003) or mechanical ventilation (OR 0.67, 95% CI 0.54-0.85, p 0.001). Women exhibited higher serum inflammatory parameters than men (median C-reactive protein 211 versus 171, p 0.0001; median erythrocyte sedimentation rate 48 versus 33, p <0.0001). Corticosteroids improved prognosis in both sexes, but absolute risk reduction was higher in women (20% versus 15%, p 0.001), although we found no significant interaction between sex and dexamethasone (p 0.38). In the multivariable analysis, male sex was an independent predictor of unfavourable outcome (OR 1.34, 95% CI 1.03-1.75, p 0.03) and death (OR 1.47, 95% CI 1.04-2.07, p 0.03).

CONCLUSIONS

Our findings show sex-based differences in adults with community-acquired bacterial meningitis. Male sex is an independent risk factor for adverse outcome. It is possible that sex-based differences in immune reaction could determine a distinct response to corticosteroids.

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.