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

Sex differences in bacterial meningitis and associations with socioeconomic indicators: a systematic review and meta-analysis with metaregression

INTRODUCTION

We aimed to describe global sex-specific proportions and case fatality ratios of bacterial meningitis and to explore their associations with the Human Development Index (HDI) and Gender Inequality Index (GII).

METHODS

Google Scholar and MEDLINE (via PubMed.gov) were searched in January 2022 using the terms "bacterial meningitis" and "mortality". Studies with a mean observation period after the year 1940 and reporting ≥10 patients with community-acquired bacterial meningitis and their survival status were included, irrespective of the participants' age. Studies that selected participants by specific risk factors, reported specific pathogens only, or had >10% missing outcomes were disregarded. Data were extracted by one researcher and validated by a second researcher. The main outcomes, sex-specific proportions and case fatality ratios, were analysed using random-effects models. Associations with HDI and GII were explored using metaregression.

RESULTS

In this meta-analysis with metaregression, from 371 studies with 157 656 meningitis episodes, 217 (58%) reported the patients' sex and 41 (11%) reported sex-specific outcomes. Proportion of males was 58% (95% CI 57%-59%, prediction interval (PI) 45%-71%). Case fatality ratios were slightly higher in females (male-to-female fatality ratio, 0.89, 95% CI 0.78 to 1.01, PI 0.53-1.49). The size of the male proportion was strongly associated with HDI (per index point, -0.64, 95% CI -0.88 to -0.40; R2 16%; p<0.001) and GII (per index point, 0.61, 95% CI 0.39 to 0.83; R2 19%; p<0.001). Sex-specific case fatality ratios were weakly associated with HDI (per index point, 0.53, 95% CI -0.19 to 1.25; R2 2%; p=0.15) and GII (per index point, -0.58, 95% CI -1.55 to 0.39; R2 7%; p=0.24).

CONCLUSION

Based on worldwide reporting from the last 80 years, we show that indicators of human development and gender inequality are associated with sex-based disparities and case fatality ratios in bacterial meningitis.

Vaccinome Landscape in Nearly 620 000 Patients With Diabetes

CONTEXT

Type 1 (T1D) and type 2 diabetes (T2D) are associated with an elevated incidence of infectious diseases and a higher risk of infections-related hospitalization and death.

OBJECTIVE

In this study, we delineated the "vaccinome" landscape obtained with a large immunization schedule offered by the Regional Government of Lombardy in a cohort of 618 396 patients with diabetes (T1D and T2D).

METHODS

Between September 2021 and September 2022, immunization coverage for influenza, meningococcus, pneumococcus, and herpes zoster was obtained from the public computerized registry of the health care system of Lombardy Region (Italy) in 618 396 patients with diabetes and in 9 534 087 subjects without diabetes. Type of diabetes, age, mortality, and hospitalizations were retrospectively analyzed in vaccinated and unvaccinated patients.

RESULTS

Among patients with diabetes (T1D and T2D), 44.6% received the influenza vaccine, 10.9% the pneumococcal vaccine, 2.5% the antimeningococcus vaccine, and 0.7% the antizoster vaccine. Patients with diabetes immunized for influenza, zoster, and meningococcus showed a 2-fold overall reduction in mortality risk and a decrease in hospitalizations. A 3-fold lower risk of mortality and a decrease in hospitalizations for both cardiac and pulmonary causes were also observed after influenza, zoster, and meningococcus immunization in older patients with diabetes.

CONCLUSION

Immunization coverage is still far from the recommended targets in patients with diabetes. Despite this, influenza vaccination protected nearly 3800 per 100 000 patients with diabetes from risk of death. The overall impressive decrease in mortality and hospitalizations observed in vaccinated patients strengthens the need for scaling up the "vaccinome" landscape in patients with diabetes.

Prophylactic vaccination strategies for adult patients with diabetes: a narrative review of safety profiles and clinical effectiveness

This narrative review analyzed roles of several prophylactic vaccinations in adult patients with diabetes, focusing on their safety profiles and clinical effectiveness. Individuals with diabetes mellitus are at increased risk for infections, making vaccination a critical component of their healthcare. The review assessed various vaccines that are particularly relevant for this population, i.e., vaccines for pneumococcus, meningococcus, severe acute respiratory syndrome coronavirus 2, influenza, herpes zoster, human papillomavirus, and dengue. It highlighted the safety profiles and clinical effectiveness of these vaccines in preventing serious infections and improving long-term health outcomes in diabetic patients. Taken together, this review emphasized the importance of prophylactic vaccinations in reducing infection-related morbidity and mortality as well as encouraged fostering greater adoption and advocacy for immunization programs among diabetic adults.

Global Case Fatality of Bacterial Meningitis During an 80-Year Period: A Systematic Review and Meta-Analysis

Importance

The impact of vaccination, antibiotics, and anti-inflammatory treatment on pathogen distribution and outcome of bacterial meningitis over the past century is uncertain.

Objective

To describe worldwide pathogen distribution and case fatality ratios of community-acquired bacterial meningitis.

Data Sources

Google Scholar and MEDLINE were searched in January 2022 using the search terms bacterial meningitis and mortality.

Study Selection

Included studies reported at least 10 patients with bacterial meningitis and survival status. Studies that selected participants by a specific risk factor, had a mean observation period before 1940, or had more than 10% of patients with health care-associated meningitis, tuberculous meningitis, or missing outcome were excluded.

Data Extraction and Synthesis

Data were extracted by 1 author and verified by a second author. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Random-effects models stratified by age (ie, neonates, children, adults), Human Development Index (ie, low-income or high-income countries), and decade and meta-regression using the study period's year as an estimator variable were used.

Main Outcome and Measure

Case fatality ratios of bacterial meningitis.

Results

This review included 371 studies performed in 108 countries from January 1, 1935, to December 31, 2019, describing 157 656 episodes. Of the 33 295 episodes for which the patients' sex was reported, 13 452 (40%) occurred in females. Causative pathogens were reported in 104 598 episodes with Neisseria meningitidis in 26 344 (25%) episodes, Streptococcus pneumoniae in 26 035 (25%) episodes, Haemophilus influenzae in 22 722 (22%), other bacteria in 19 161 (18%) episodes, and unidentified pathogen in 10 336 (10%) episodes. The overall case fatality ratio was 18% (95% CI, 16%-19%), decreasing from 32% (95% CI, 24%-40%) before 1961 to 15% (95% CI, 12%-19%) after 2010. It was highest in meningitis caused by Listeria monocytogenes at 27% (95% CI, 24%-31%) and pneumococci at 24% (95% CI, 22%-26%), compared with meningitis caused by meningococci at 9% (95% CI, 8%-10%) or H influenzae at 11% (95% CI, 10%-13%). Meta-regression showed decreasing case fatality ratios overall and stratified by S pneumoniae, Escherichia coli, or Streptococcus agalactiae (P < .001).

Conclusions and Relevance

In this meta-analysis with meta-regression, declining case fatality ratios of community-acquired bacterial meningitis throughout the last century were observed, but a high burden of disease remained.

Assessment of potential drug-related problems (PDRP) and clinical outcomes in bacterial meningitis patients admitted to tertiary care hospitals

Meningitis is an important cause of morbidity and mortality in children and adults. Its treatment strategy varies with age and gender. To assess potential drug-related problems (PDRP) and clinical outcomes in bacterial meningitis patients, a multicenter, clinical, descriptive, cross-sectional prospective observational study in 120 patients admitted to different tertiary care hospitals in Karachi was conducted. It includes both males 48% and females 52% belonging from all age groups i.e. peadiatrics (01 to 12 years), adults (18 to 65 years), and geriatrics (66 to 75 years). Out of these 72 patients were admitted in the public sector and 48 patients were admitted in private sector hospitals. Nosocomial infections were developed in 41% of patients during their stay at the hospital. Potentially nephrotoxic drugs were administered to all BM patients, these drugs should be administered carefully. Majorly Ceftriaxone was administered to 86% of patients, Vancomycin 71%, and meropenem 73% whereas 68% of patients were administered piperacillin-tazobactam. Organisms involved as causative agents in the majority of patients are Neisseria meningitides, Pseudomonas aeruginosa and, Streptococcus pneumoniae. DRPs impacted patient clinical outcomes in presence of many other factors like comorbidities, DDIs, Nis, administration of potentially nephrotoxic drugs, and administration of watch group and reserve group antibiotics without having culture sensitivity test, even after having CST no principles of de-escalation for antibiotics were done, which is a very important factor for hospitalized patients having IV antibiotics. The mortality rate among BM patients was 66%. The majority of patients (87%) stay at the hospital was 1-10 days. The present study helped in the identification of DRPs along with some other factors affecting the clinical outcomes in patients suffering from bacterial meningitis. Healthcare professionals should receive awareness and education on the importance of CST before initiating antibiotic therapy. Pharmacist-led medication review is necessary and should be followed to avoid negative outcomes and serious consequences related to DRPs.

[Invasive meningococcal disease: increased risk and vaccination prevention for immunocompromised patients]

BACKGROUND

The development of evidence-based guidelines for the prevention of infectious diseases through vaccination requires an understanding of populations that most likely may obtain an infection, severe illness or disease. Targeted vaccination recommendations are made possible by identifying risk groups, as is the case with meningococcal infections. Despite falling case numbers, meningococcal sepsis and meningococcal meningitis remain a major health problem.

METHOD

A systematic literature search was carried out on the research platform Ovid.

RESULTS

Vulnerable groups of people whose immune system is limited by primary and secondary immunodeficiency, such as asplenia, renal failure, human immunodeficiency virus (HIV) infection, diabetes, complement deficiency, organ and stem cell transplants, or immunomodulatory therapy (e.g., in rheumatic, hematological or oncological diseases), are exposed to an increased risk of infection and more severe courses of disease. Despite adequate medical care, the mortality rate is high and patients that survived the infection are often suffering from severe long-term sequelae. In such cases, the vaccination recommendations of the Standing Committee on Vaccination (STIKO) for indication vaccinations and the application instructions for vaccination in the case of immune deficiency should be consistently implemented in Germany.

CONCLUSIONS

Increased responsibility for comprehensive protection must be assumed for persons with underlying diseases. Reducing invasive meningococcal infections can be achieved through widespread education of patients and contacts, as well as practicing physicians on available vaccinations.

Acute Bacterial Meningitis in Healthy Adult Patients: A Prospective Cohort Study

Spontaneous bacterial meningitis (BM) is more common among patients with underlying conditions, but its characteristics in previously healthy patients are not well described. We analyzed the time trends of BM in terms of characteristics, and outcomes in patients without comorbidities.

PATIENTS AND METHODS

Single-center, prospective observational cohort study of 328 adults with BM hospitalized in a tertiary university hospital in Barcelona (Spain). We compared the features of infections diagnosed in 1982-2000 and 2001-2019. The main outcome measure was in-hospital mortality.

RESULTS

The median age of the patients increased from 37 to 45 years. Meningococcal meningitis significantly diminished (56% versus 31%, p < 0.000) whereas listerial meningitis increased (1.2% versus 8%, p = 0.004). Systemic complications were more common in the second period, although mortality did not vary significantly between periods (10.4% versus 9.2%). However, after adjusting for relevant variables, infection in the second period was associated with lower risk death.

CONCLUSIONS

Adult patients without underlying comorbidities that developed BM in recent years were older and more likely to have pneumococcal or listerial infections and systemic complications. In-hospital death was less likely in the second period, after adjusting for risk factors of mortality.

Association of Diabetes with Meningitis Infection Risks: A Systematic Review and Meta-Analysis

Background

The Global Burden of Disease Study in 2016 estimated that the global incident cases of meningitis have increased by 320,000 between 1990 and 2016. Current evidence suggests that diabetes may be a prime risk factor for meningitis among individuals, including older adults. However, findings of prior studies on this topic remain inconsistent, making a general conclusion relatively difficult. This study aimed to quantitatively synthesize the literature on the risk of meningitis associated with diabetes and compare the risk across different global regions.

Method

Literature search and study design protocol followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was conducted in PubMed, Web of Science, African Journal Online, and Google Scholar using relevant MESH terms. A random effect model was used to pull effect sizes.

Results

Initial search yielded 772 papers but 756 studies were excluded due to duplicity and not meeting inclusion criteria. In all, 16 papers involving 16847 cases were used. The pulled effect size (ES) of the association between diabetes and meningitis was 2.240 (OR = 2.240, 95% CI = 1.716-2.924). Regional-base analysis showed that diabetes increased the risk of developing meningitis in Europe (OR = 1.737, 95% CI = 1.299-2.323), Asia (OR = 2.192, 95% CI = 1.233-3.898), and North America (OR = 2.819, 95% CI = 1.159-6.855). These associations remained significant in the study design and etiological classe-based subgroup analyses. However, we surprisingly found no studies in Africa or South America.

Conclusion

Diabetes is a risk factor for developing meningitis. Given that no research on this topic came from Africa and South America, our findings should be contextually interpreted. We, however, encourage studies on diabetes-meningitis linkages from all parts of the world, particularly in Africa and South America, to confirm the findings of the present study.

Pyruvate Oxidase as a Key Determinant of Pneumococcal Viability during Transcytosis across Brain Endothelium

Streptococcus pneumoniae invades a myriad of host tissues following efficient breaching of cellular barriers. However, strategies adopted by pneumococcus for evasion of host intracellular defenses governing successful transcytosis across host cellular barriers remain elusive. In this study, using brain endothelium as a model host barrier, we observed that pneumococcus containing endocytic vacuoles (PCVs), formed following S. pneumoniae internalization into brain microvascular endothelial cells (BMECs), undergo early maturation and acidification, with a major subset acquiring lysosome-like characteristics. Exploration of measures that would preserve pneumococcal viability in the lethal acidic pH of these lysosome-like vacuoles revealed a critical role of the two-component system response regulator, CiaR, which was previously implicated in induction of acid tolerance response. Pyruvate oxidase (SpxB), a key sugar-metabolizing enzyme that catalyzes oxidative decarboxylation of pyruvate to acetyl phosphate, was found to contribute to acid stress tolerance, presumably via acetyl phosphate-mediated phosphorylation and activation of CiaR, independent of its cognate kinase CiaH. Hydrogen peroxide, the by-product of an SpxB-catalyzed reaction, was also found to improve pneumococcal intracellular survival by oxidative inactivation of lysosomal cysteine cathepsins, thus compromising the degradative capacity of the host lysosomes. As expected, a ΔspxB mutant was found to be significantly attenuated in its ability to survive inside the BMEC endocytic vacuoles, reflecting its reduced transcytosis ability. Collectively, our studies establish SpxB as an important virulence determinant facilitating pneumococcal survival inside host cells, ensuring successful trafficking across host cellular barriers. IMPORTANCE Host cellular barriers have innate immune defenses to restrict microbial passage into sterile compartments. Here, by focusing on the blood-brain barrier endothelium, we investigated mechanisms that enable Streptococcus pneumoniae to traverse through host barriers. Pyruvate oxidase, a pneumococcal sugar-metabolizing enzyme, was found to play a crucial role in this via generation of acetyl phosphate and hydrogen peroxide. A two-pronged approach consisting of acetyl phosphate-mediated activation of acid tolerance response and hydrogen peroxide-mediated inactivation of lysosomal enzymes enabled pneumococci to maintain viability inside the degradative vacuoles of the brain endothelium for successful transcytosis across the barrier. Thus, pyruvate oxidase is a key virulence determinant and can potentially serve as a viable candidate for therapeutic interventions for better management of invasive pneumococcal diseases.

The Potentials of Melatonin in the Prevention and Treatment of Bacterial Meningitis Disease

Bacterial meningitis (BM) is an acute infectious central nervous system (CNS) disease worldwide, occurring with 50% of the survivors left with a long-term serious sequela. Acute bacterial meningitis is more prevalent in resource-poor than resource-rich areas. The pathogenesis of BM involves complex mechanisms that are related to bacterial survival and multiplication in the bloodstream, increased permeability of blood-brain barrier (BBB), oxidative stress, and excessive inflammatory response in CNS. Considering drug-resistant bacteria increases the difficulty of meningitis treatment and the vaccine also has been limited to several serotypes, and the morbidity rate of BM still is very high. With recent development in neurology, there is promising progress for drug supplements of effectively preventing and treating BM. Several in vivo and in vitro studies have elaborated on understanding the significant mechanism of melatonin on BM. Melatonin is mainly secreted in the pineal gland and can cross the BBB. Melatonin and its metabolite have been reported as effective antioxidants and anti-inflammation, which are potentially useful as prevention and treatment therapy of BM. In bacterial meningitis, melatonin can play multiple protection effects in BM through various mechanisms, including immune response, antibacterial ability, the protection of BBB integrity, free radical scavenging, anti-inflammation, signaling pathways, and gut microbiome. This manuscript summarizes the major neuroprotective mechanisms of melatonin and explores the potential prevention and treatment approaches aimed at reducing morbidity and alleviating nerve injury of BM.