Meningococcal pneumonia: a review

Humoral and cellular immune responses induced by serogroup W135 meningococcal conjugate and polysaccharide vaccines

Investigating the mechanisms by which W135 meningococcal conjugate (PSW135-TT) activates adaptive immune responses in mice can provide a comprehensive understanding of the immune mechanisms of bacterial polysaccharide conjugate vaccines. We compared B-cell and T-cell immune responses immunized with W135 meningococcal capsular polysaccharides (PSW135), tetanus toxoid (TT) and PSW135-TT in mice. The results showed that PSW135-TT could induce higher PSW135-specific and TT-specific IgG antibodies with a significant enhancement after two doses. All serum antibodies immunized with PSW135- TT had strong bactericidal activity, whereas none of the serum antibodies immunized with PSW135 had bactericidal activity. Besides, IgM and IgG antibodies immunized with PSW135-TT after two doses were positively correlated with the titer of bactericidal antibodies. We also found Th cells favored Th2 humoral immune responses in PSW135-TT, PSW135, and TT-immunized mice, especially peripheral blood lymphocytes. Furthermore, PSW135-TT and TT could effectively activate bone marrow derived dendritic cells (BMDCs) and promote BMDCs to highly express major histocompatibility complex Ⅱ (MHCⅡ), CD86 and CD40 molecules in mice, whereas PSW135 couldn't. These data verified the typical characteristics of PSW135-TT and TT as T cell dependent antigen (TD-Ag) and PSW135 as T cell independent antigen (TI-Ag), which will be very helpful for further exploration of the immune mechanism of polysaccharide-protein conjugate vaccines and improvement of the quality of bacterial polysaccharide conjugate vaccines in future.

Nasopharyngeal Meningococcal Carriage among Older Adults in Türkiye (MeninGOLD Study)

Introduction: While there is a significant amount of information about invasive meningococcal disease (IMD), meningococcal carriage, and meningococcal vaccines in children and adolescents, data in older adults are limited. Studies of meningococcal carriage and transmission modeling can be utilized to predict the spread of IMD and guide prevention and treatment strategies. Our study's main objective was to assess the prevalece of Neisseria meningitidis (Nm) carriage, serogroup distribution, and associated risk factors among older adults in Türkiye. Methods: Nasopharyngeal samples were collected between December 2022 and January 2023 from a total of 329 older adults (65 years of age and above). The samples were tested via PCR for Nm, and a serogroup (A, B, C, Y, W, X, E, Z, H) analysis of the positive samples was performed. Results: In total, 329 adults over 65 years of age (150 females and 179 males; 69% were 65-75 years old and 31% were 75 years of age and older) were included in the study. Nm carriage was detected in 46 participants (13.9%), and the serogroup distribution was as follows: 2.4% MenY (n = 8), 1.8% MenB (n = 6), 0.2% MenW (n = 2), and 9.4% non-groupable (n = 31). Other serogroups were not detected. Between the meningococcal carriers and the non-carriers, there were no differences between previous vaccination histories (meningococcal, pneumococcal, influenza, and COVID-19), travel history for Hajj and/or Umrah, and the presence of chronic disease. Of the 16 cases positive for the serogroups Y, B, and W, 13 patients were between the ages of 65 and 74 and three patients were over 75 years old, and these three cases represented MenY. Conclusion: In our study, the percentage of meningococcal carriage was found to be 13.9%, the carriage rate for encapsulated strains was 4.8%, and the most common serogroup was MenY. Men Y was also the only serogroup detected in patients over 75 years of age. The MenY serogroup, which is one of the most important causes of IMD (especially in pneumonia cases) in people older than 65 years, was the most frequently carried serogroup in people over 65 years of age in our study. Adequate surveillance and/or a proper carriage study would help to define potential vaccination strategies for older adults.

Investigation of Upper Respiratory Carriage of Bacterial Pathogens among University Students in Kampar, Malaysia

The carriage of bacterial pathogens in the human upper respiratory tract (URT) is associated with a risk of invasive respiratory tract infections, but the related epidemiological information on this at the population level is scarce in Malaysia. This study aimed to investigate the URT carriage of Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa among 100 university students by nasal and oropharyngeal swabbing. The presence of S. aureus, K. pneumoniae and P. aeruginosa was assessed via swab culture on selective media and PCR on the resulting isolates. For S. pneumoniae, H. influenzae and N. meningitidis, their presence was assessed via multiplex PCR on the total DNA extracts from chocolate agar cultures. The carriage prevalence of H. influenzae, S. aureus, S. pneumoniae, K. pneumoniae, N. meningitidis and P. aeruginosa among the subjects was 36%, 27%, 15%, 11%, 5% and 1%, respectively, by these approaches. Their carriage was significantly higher in males compared to females overall. The S. aureus, K. pneumoniae and P. aeruginosa isolates were also screened by the Kirby-Bauer assay, in which 51.6% of S. aureus were penicillin-resistant. The outcomes from carriage studies are expected to contribute to informing infectious disease control policies and guidelines.

Serogroup B Meningococcal Sepsis and Meningitis Associated With Meningococcal Acute Otitis Media, and Paranasal Sinusitis in an Infant: A Case Report

Meningococcal disease (MD) is a potentially lethal condition. Typically, following infection, MD manifests with high fever, with signs and symptoms of severe septicemia with or without purpura, and in more than half of cases with meningitis. Acute otitis media (AOM) caused by Neisseria meningitidis has scarcely been reported, mostly without severe MD, and there are no reports of meningococcal paranasal sinusitis (PS). We present the case of a previously healthy 11-month-old infant who started with fever and cough and further developed intense irritability and right spontaneous purulent otorrhea, with subsequent increased fever and seizures. Blood, cerebrospinal, and middle ear fluid cultures were positive for N. meningitidis serogroup B, and a CT scan showed both maxillary and ethmoidal sinusitis. Intravenous ceftriaxone was administered for eight days, and three months following discharge, no sequelae were identified. This is the first report of a patient with MD associated with sepsis, meningitis, AOM, and PS.

Invasive Meningococcal Disease and COVID-19 Co-Infection: A Case Report

This case report presents a 53-year-old male patient infected with COVID-19 who developed acute respiratory distress syndrome (ARDS) and septic shock due to meningococcemia, despite the absence of clinical signs of meningitis. This patient's condition was complicated by pneumonia in the setting of myocardial failure. In the curse of the disease, it is remarked that the importance of early recognition of sepsis symptoms is crucial in distinguishing patients with COVID-19 from those with other infections and preventing fatal outcomes. The case presented an excellent opportunity to review meningococcal disease's intrinsic and extrinsic risk factors. With the identified risk factors, we propose different measures to be considered to diminish and recognize this fatal disease early.

Prevention of infections including vaccination strategies in multiple myeloma

Infections are a major cause of morbidity and mortality in multiple myeloma. The increased risk for bacterial and viral infections results mainly from the disease-inherent and treatment-induced immunosuppression. Additional risk factors are older age with immune senescence, T cell depletion, polymorbidity, and male gender. Hence, every effort should be taken to reduce the risk for infections by identifying patients at higher risk for these complications and by implementing prophylactic measures, including chemoprophylaxis and immunization against various relevant pathogens. Here, we review the available evidence and provide recommendations for medical prophylaxis and vaccination in clinical practice.

Progressive Cerebral Venous Thrombosis with Cranial Nerve Palsies in an Adolescent African Girl & Associated Diagnostic Pitfalls: A Rare Case Report

Cerebral venous thrombosis (CVT) is a cerebrovascular disorder caused by complete or partial occlusion of the cerebral venous and sinus system. The etiology has been attributed to hypercoagulability and pro-thrombotic states, leading to raised intracranial pressures that often manifest as headaches and focal neurological deficits. However, the multifactorial nature of CVT can create a diagnostic conundrum for clinicians. We describe a unique case of a 16-year-old female who presented with convulsions, postictal confusion, and drowsiness followed by residual weakness of her extremities. She initially presented to the primary care center with headache, high-grade fever, and altered mental status and was empirically treated for pyogenic meningitis. The patient failed to improve with a week of antibiotics and was referred to the tertiary care center for urgent attention. On presentation, the patient developed VI and VII cranial nerve palsy. Subsequently, MRI images showed filling defects in the superior sagittal, right transverse, and sigmoid sinuses with right parietal gyral T1 hyperintensity and T2 hypo-intensity. She was diagnosed with septic CVT based on sinus venous thrombosis and venous infarction, probably secondary to meningococcal pneumonia. It can be challenging to distinguish between both conditions as their presentations overlap. Moreover, cranial nerve palsy is an infrequent manifestation of CVT, with unclear pathogenesis. We highlight the role of neuro-imaging in the early detection of CVT and bring to light the unfamiliar symptoms and a more varied clinical spectrum that may hinder the diagnosis in a limited-resource setting. Future research should be explicitly modeled to improve the diagnostic efficiency of CVT and improve outcomes in younger patient populations.

Non-serogroupable Neisseria meningitidis pneumonia in an immunocompetent patient with severe COVID-19 pneumonia: A case report

Background

Non-serogroupable Neisseria meningitidis (N. meningitidis), the most common type of N. meningitidis in asymptomatic carriers, rarely causes infections. Most reported cases of infection are in patients with immunodeficiency, primarily complement deficiencies.

Case presentation

A 54-year-old immunocompetent man was transferred to our hospital to treat severe coronavirus disease 2019 (COVID-19). The patient presented with cough producing a large amount of purulent sputum, which was considered an atypical presentation of COVID-19. Gram staining of the sputum revealed a large number of gram-negative diplococci phagocytosed by many neutrophils, and a diagnosis of bacterial pneumonia was established. The culture yielded non-serogroupable N. meningitidis, and the patient was diagnosed with non-serogroupable N. meningitidis pneumonia. Potential immunodeficiency was considered; however, testing including human immunodeficiency virus and complement factors showed no abnormalities.

Conclusions

We report herein a rare case of non-serogroupable N. meningitidis pneumonia that occurred in an immunocompetent patient during the course of severe COVID-19. We consider impaired T cell function attributable to COVID-19 and dexamethasone administration may have triggered a transient immunosuppressive state and led to non-serogroupable N. meningitidis pneumonia.

Equity in vaccination policies to overcome social deprivation as a risk factor for invasive meningococcal disease

INTRODUCTION

Social deprivation is associated with poorer healthcare access. Vaccination is among the most effective public health interventions and achieving equity in vaccination access is vitally important. However, vaccines are often reimbursed by public funds only when recommended in national immunization programs (NIPs), which can increase inequity between high and low socioeconomic groups. Invasive meningococcal disease (IMD) is a serious vaccination-preventable disease. This review focuses on vaccination strategies against IMD designed to reduce inequity.

AREAS COVERED

We reviewed meningococcal epidemiology and current vaccination recommendations worldwide. We also reviewed studies demonstrating an association between social deprivation and risk of meningococcal disease, as well as studies demonstrating an impact of social deprivation on uptake of meningococcal vaccines. We discuss factors influencing inclusion of meningococcal vaccines in NIPs.

EXPERT OPINION

Incorporating meningococcal vaccines in NIPs is necessary to reduce inequity, but insufficient alone. Inclusion provides clear guidance to healthcare professionals and helps to ensure that vaccines are offered universally to all target groups. Beyond NIPs, cost of vaccination should be reimbursed especially for disadvantaged individuals. These approaches should help to achieve optimal protection against IMD, by increasing access and immunization rates, eventually reducing social inequities, and helping to protect those at greatest risk.

Care pathways in invasive meningococcal disease: a retrospective analysis of the French national public health insurance database

Invasive meningococcal disease (IMD) carries a high burden in terms of mortality, long-term complications, and cost, which can be significantly reduced by vaccination. The objectives of this case–control study were to document the care pathways of patients with IMD before, during, and after hospitalization and to assess in-hospital complications and long-term sequelae. Cases consisted of all people hospitalized for IMD in France between 2012 and 2017. Controls were matched by age, gender, and district of residence. Data were extracted from the French national public health insurance database on demographics, hospitalizations, mortality and potential sequelae of IMD. Overall, 3,532 cases and 10,590 controls were assessed and followed up for 2.8 years (median). During hospitalization, 1,577 cases (44.6%) stayed in an intensive care unit, 1,238 (35.1%) required mechanical ventilation, and 43 (1.2%) underwent amputation; 293 cases (8.3%) died in hospital and a further 163 (4.6%) died following discharge; 823 cases (25.4% of survivors) presented ≥1 sequela and 298 (9.2%) presented multiple sequelae. The most frequently documented sequelae were epilepsy (N = 205; 5.8%), anxiety (N = 196; 5.5%), and severe neurological disorders (N = 193; 5.5%). All individual sequelae were significantly more frequent (p < .0001) in cases than controls. Hearing/visual impairment and communication problems were conditions that presented the highest risk for cases compared to controls (risk ratios >20 in all cases). In conclusion, this study highlights the importance of providing optimal medical care for patients with IMD, of minimizing the delay before hospitalization, and of effective prevention through comprehensive vaccination programs.

Benefits of providing optimal medical care for IMD patients.

Importance of minimising the delay before hospitalization.

IMD remains challenging to diagnose, and vaccination is the most efficient way to prevent the disease and its complications.

A Double Whammy Pneumonia: The First Reported Case of Concurrent Neisseria meningitidis and SARS-CoV-2 Pneumonia

Meningococcal pneumonia (MP) is a rare manifestation of meningococcal disease. The MP was first described in 1907 when Neisseria meningitidis (NM) isolates were identified in sputum samples obtained from soldiers with pneumonia. Preceding and concurrent viral infections constitute a major risk for MP. During the 1918-1919 influenza pandemic, a significant increase in MP cases were reported in patients with preceding influenza infection. Despite the end of the last H1N1 influenza pandemic in 2010, seasonal influenza infections still pose a risk for simultaneous MP. History appears to be repeating itself with concomitant bacterial and viral coinfection amid the current SARS-CoV-2 pandemic. Herein presented is a unique case of an elderly woman who presented with, to the best of our knowledge, the first reported case of possible concurrent SARS-CoV-2 and MP infections.

Implementation of a prospective study for enhancing surveillance of invasive bacterial infections in North Africa

OBJECTIVES

We implemented a project named MENINGSTOP in three countries of North Africa (Algeria, Morocco and Tunisia). The main objective was to use real-time PCR to detect, identify and type the three main agents (Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae) responsible for invasive bacterial infections (IBI).

METHODS

The protocol of WHO and US CDC for real-time PCR was used to detect and type the three bacterial agents in clinical samples. We also designated two quality exercises using an external interlaboratory study and cross-testing of 10% of randomly selected samples.

RESULTS

Among the 752 samples tested, 18% were positive for one of the three agents. N. meningitidis was the most frequent globally reaching 9% of all samples (7% to 17% range) followed by S. pneumoniae 8% of all samples (6% to 15%). Group B meningococci was the most frequent (74% of all positive samples for meningococci and ranging from 50% to 90%). Quality assurance showed >85% correlation scores.

CONCLUSIONS

Real-time PCR can help improving epidemiological surveillance. Data confirm the prevalence of meningococci B. Our project adds a reliable tool to enhance surveillance and to help decision making in vaccination strategies against IBI.

Global epidemiology and changing clinical presentations of invasive meningococcal disease: a narrative review

Neisseria meningitidis (the meningococcus) causes significant morbidity and mortality worldwide through an epidemic or sporadic invasive infections. The epidemiology of N. meningitidis is changing and unpredictable. Certain emerging meningococcal genotypes seem to be associated with increasing unusual clinical presentations. Indeed, early symptoms may vary and are frequently non-specific. However, atypical clinical forms including abdominal presentations, septic arthritis, and bacteremic pneumonia may lead to misdiagnosis and some are usually associated with higher case fatality rates due to delayed optimal management. Improving awareness of clinicians and public health specialists about these unusual but potentially severe presentations should help establish prompt diagnoses and provide appropriate management of cases. In this review, we described unusual panels of clinical presentations of invasive meningococcal disease linked to the recent changes in meningococcal epidemiology.

Healthcare Resource Consumption and Cost of Invasive Meningococcal Disease in France: A Study of the National Health Insurance Database

Introduction

Invasive meningococcal disease (IMD) is an uncommon but serious infectious disease. Its economic burden is known to be high but is poorly characterised. The objective of this study was to determine costs, as captured in the healthcare claims database, incurred by all patients hospitalised for IMD in France over a 6-year period.

Methods

This case–control study was performed using the French national public health insurance database (SNDS). Cases comprised all individuals hospitalised with acute IMD in France between 2012 and 2017 inclusive. For each case, three controls were identified, matched for age, gender and region of residence. All healthcare resource consumption by cases and controls during the follow-up period was documented. Costs were analysed for the index hospitalisation in cases, 1 year following the index date and then for 5 years following the index date. Costs were assigned from national tariffs. The analysis was performed from a societal perspective. IMD sequelae were identified from hospital discharge summaries.

Results

A total of 3532 cases and 10,590 controls were evaluated. The mean per capita cost of the index IMD hospitalisation was €11,256, and increased with age and with the presence of sequelae. In the year following the index date, mean per capita direct medical costs were €6564 in cases and €2890 in controls. Annual costs were €4254 in cases without sequelae, €10,799 in cases with one sequela and €20,096 in cases with more than one sequela. In the fifth year of follow-up, mean per capita costs were €2646 in cases and €1478 in controls. The excess cost in cases was principally due to the management of sequelae. Amputation, skin scarring and mental retardation generated per capita costs in excess of €20,000 in the first year and in excess of €10,000 for subsequent years.

Conclusion

The economic burden of IMD in France is high and, over the long-term, is driven by sequelae management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00468-w.

Risk factors for invasive meningococcal disease: a retrospective analysis of the French national public health insurance database

Vaccination of at-risk populations against Neisseria meningitidis is an important strategy to prevent invasive meningococcal disease (IMD). The objective of this study was to characterize preexisting risk factors in patients with IMD and to compare their relative importance. This case-control analysis was performed in the French national public health insurance database (SNDS). Cases consisted of all people hospitalized for IMD in France over a six-year period (2012–2017). Controls were matched by age, gender, and district of residence. Medical risk factors were identified from ICD-10 codes in the SNDS. Socioeconomic risk factors studied were low household income and social deprivation of the municipality of residence. Associations of these risk factors with hospitalization for IMD were quantified as odds ratios (ORs) between cases and controls with their 95% confidence intervals (95%CI). The medical risk factors showing the most robust associations were congenital immunodeficiency (OR: 39.1 [95%CI: 5.1–299], acquired immunodeficiency (10.3 [4.5–24.0]) and asplenia/hyposplenia (6.7 [3.7–14.7]). In addition, certain chronic medical conditions, such as autoimmune disorders (5.4 [2.5–11.8]), hemophilia (4.7 [1.8–12.2]) and severe chronic respiratory disorders (4.3 [3.1–6.2]) were also strongly associated, as was low household income (1.68 [1.49–1.80]). In conclusion, this study has documented potential risk factors associated with hospitalization for IMD in a large and comprehensive sample of individuals with IMD in France. Several of the risk factors identified may help identify groups who could benefit from targeted prevention measures (such as vaccination) in order to reduce the burden of IMD.

Impact of COVID-19 pandemic and the lockdown on invasive meningococcal disease

Objective

Few data are available on the association between SARS-CoV-2 and secondary bacterial infections. Such an association was described for flu and invasive meningococcal disease (IMD). We aimed exploring such a correlation between COVID-19 and IMD as well as the impact of the lockdown on IMD.

Results

We compared IMD cases received at the French National Reference Centre for meningococci and Haemophilus influenzae that are sent as part of the mandatory reporting of IMD. We compared these data during the period 01 January-15 May 2020 to those from the same period in 2018 and 2019. IMD cases that were associated with respiratory presentations significantly increased in 2020 compared to 2018 (P = 0.029) and 2019 (P = 0.002), involved elderly and were due to unusual isolates. However, IMD cases due to hyperinvasive isolates decreased during the lockdown. Enhancing IMD surveillance and anti-meningococcal vaccination in elderly should be addressed.

Recommendations for vaccination in multiple myeloma: a consensus of the European Myeloma Network

Vaccination is one of the most successful medical interventions that has saved the life of millions of people. Vaccination is particularly important in patients with multiple myeloma, who have an increased risk of infections due to the disease-inherent immune suppression, and because of the immune suppressive effects of therapy. Hence, all appropriate measures should be exploited, to elicit an effective immune response to common pathogens like influenza, pneumococci, varicella zoster virus, and to those bacteria and viruses (haemophilus influenzae, meningococci, and hepatitis) that frequently may pose a significant risk to patients with multiple myeloma. Patients after autologous, and specifically after allogeneic transplantation have severely reduced antibody titers, and therefore require a broader spectrum of vaccinations. Response to vaccination in myeloma often is less vigorous than in the general population, mandating either measurement of the postvaccination antibody titers and/or repeating the vaccination. Here, we compile the existing data on vaccination in multiple myeloma and provide recommendations for clinical practice.

Evaluation of Extraction Methods for Clinical Metagenomic Assay

(1) Background: Clinical metagenomics is a promising approach that helps to identify etiological agents in cases of unknown infections. For the efficient detection of an unknown pathogen, the extraction method must be carefully selected for the maximum recovery of nucleic acid from different microorganisms. The aim of this study was to evaluate different extraction methods that have the ability to isolate nucleic acids from different types of pathogens with good quality and quantity for efficient use in clinical metagenomic identification. (2) Methods: A mock sample spiked with five different pathogens was used for the comparative evaluation of different commercial extraction kits. Extracted samples were subjected to library preparation and run on MiSeq. The selected extraction method based on the outcome of the comparative evaluation was used subsequently for the nucleic acid isolation of all infectious agents in clinical respiratory samples with multiple infections. (3) Results: The protocol using the PowerViral^® Environmental RNA-DNA Isolation Kit with a 5-min bead beating step achieved the best results with a low starting volume. The analysis of the tested clinical specimens showed the ability to successfully identify different types of pathogens. (4) Conclusions: The optimized extraction protocol in this study is recommended for clinical metagenomics application in specimens with multiple infections from different taxa.

Conformational changes of DNA repair glycosylase MutM triggered by DNA binding

Bacterial MutM is a DNA repair glycosylase removing DNA damage generated from oxidative stress and, therefore, preventing mutations and genomic instability. MutM belongs to the Fpg/Nei family of prokaryotic enzymes sharing structural and functional similarities with their eukaryotic counterparts, for example, NEIL1-NEIL3. Here, we present two crystal structures of MutM from pathogenic Neisseria meningitidis: a MutM holoenzyme and MutM bound to DNA. The free enzyme exists in an open conformation, while upon binding to DNA, both the enzyme and DNA undergo substantial structural changes and domain rearrangement. Our data show that not only NEI glycosylases but also the MutMs undergo dramatic conformational changes. Moreover, crystallographic data support the previously published observations that MutM enzymes are rather flexible and dynamic molecules.

Recent changes of invasive meningococcal disease in France: arguments to revise the vaccination strategy in view of those of other countries

In France, the incidence of invasive meningococcal disease (IMD) is around 1/100,000, with the following trends over the 2011-2018 period: a leading role of group B in subjects <15 years, a decrease of group C among <1 year since 2017, an increase of group W in all age groups including subjects <1 year since 2014 and a positive correlation between group Y and age group. In Europe, vaccination progressed with conjugate ACWY vaccines and proteins-based B vaccines. Their benefit-risk-cost balance is however not so obvious for area at low incidence (<2/100,000), explaining tremendous variations between countries, from no recommendation to recommend all available vaccines. In France, the calendar still includes only C with a good adhesion in infants but a fiasco of the catch-up campaign in adolescents and young adults. In Europe, it is time to consider not only national epidemiology but also trends in the neighborhood. The increase of group W cases encourages switching C to ACWY vaccine both in infants and adolescents. It is also time to protect infants with B vaccine. Large pedagogy on the disease is required to increase the adhesion to the vaccination and to recognize and treat earlier the residual cases.