Characteristics and changes in invasive meningococcal disease epidemiology in France, 2006–2015

Recent increase in atypical presentations of invasive meningococcal disease in France

BACKGROUND

Invasive meningococcal disease (IMD) cases declined upon the implementation of non-pharmaceutical interventions (NPI) (social distancing and mask wearing) to control the COVID-19 pandemic but rebounded in 2022 in numbers with genotypical changes of the strains. We explored here associated modifications in the clinical presentations of IMD.

METHODS

We conducted a retrospective descriptive study using the Database of the French National Reference Centre for meningococci and Haemophilus influnezae for IMD cases between 2015 and 2022. We scored serogroups, sex, age groups, clinical presentations and clonal complexes of the corresponding patients and isolates.

FINDINGS

Non-meningeal forms of IMD increased significantly upon easing of NPI, such as bacteremic meningococcal pneumonia and bacteremic abdominal forms. They represented 6% and 8% of all IMD forms and were significantly linked to serogroups Y and W respectively, to older adults for bacteremic pneumonia and to young adults for bacteremic abdominal presentations. These forms were significantly associated with more early mortality and clonal complexes 23, 11 and 9316.

INTERPRETATION

The increase in atypical IMD forms may lead to higher burden of IMD due to delayed diagnosis and management. Updating prevention may be needed through by adapting the current vaccination strategies to epidemiological changes.

Invasive meningococcal disease in older adults: current perspectives and call for action

PURPOSE

Invasive meningococcal disease (IMD) is a devastating condition. While most attention is directed towards disease in children and adolescents, IMD poses an important cause of morbidity and mortality in adults ≥60 years. While immunization is a critical component of healthy ageing strategies, meningococcal immunization is not routinely offered to older adults. The aim of this review was to summarize clinical and epidemiological aspects of IMD and available immunization strategies, with a particular focus on disease in older individuals, to emphasize the importance of this rather neglected area.

METHODS

An expert working group was established to evaluate clinical and epidemiological data to raise awareness of IMD in older individuals, and develop suggestions to improve the existing burden.

RESULTS

Routine child and adolescent meningococcal immunization has substantially reduced IMD in these targeted populations. Consequently, prevalence and proportion of IMD among those ≥60 years, mostly unvaccinated, is increasing in developed countries (accounting for up to 25% of cases). IMD-related mortality is highest in this age-group, with substantial sequelae in survivors. IMD due to serogroups W and Y is more prevalent among older adults, often with atypical clinical features (pneumonia, gastrointestinal presentations) which may delay timely treatment.

CONCLUSIONS

IMD in older adults remains overlooked and greater awareness is required at clinical and societal levels. We encourage clinicians and immunization policy makers to reconsider IMD, with a call for action to remedy existing inequity in older adult access to protective meningococcal immunization.

Not Only Meningitis but Also Epiglottitis: An Emerging Clinical Presentation of Invasive Meningococcal Disease

The rebound of invasive meningococcal disease cases in France since the fall of 2022 was accompanied by an increase in adult epiglottitis. These cases were provoked mainly by isolates of serogroup W belonging to the clonal complex 11 of Neisseria meningitidis. Awareness and surveillance should be reinforced.

The rapid rebound of invasive meningococcal disease in France at the end of 2022

BACKGROUND

Invasive meningococcal disease (IMD) cases declined upon the implementation of non-pharmaceutical measures to control the COVID-19 pandemic. A rebound in IMD cases was feared upon easing these measures.

METHODS

We conducted a retrospective descriptive study using the French National Reference Center Database for meningococci between 2015 and 2022. We scored serogroups, sex, age groups, and clonal complexes of the corresponding isolates.

FINDINGS

Our data clearly show a decline in the number of IMD cases for all serogroups and age groups until 2021. This decline was mainly due to a decrease in IMD cases provoked by the hyperinvasive ST-11 clonal complex. However, since the fall of 2021, there has been an increase in IMD cases, which accelerated in the second half of 2022. This rebound concerned all age groups, in particular 16-24 years. The increase in cases due to serogroups B, W, and Y were mainly due to the expansion of isolates of the ST-7460, the clonal complex ST-9316 and the clonal complex ST-23, respectively.

INTERPRETATION

IMD epidemiology changes constantly and profound epidemiological changes have been recently observed. The surveillance of IMD needs to be enhanced using molecular tools. Additionally, vaccination strategies need to be updated to acknowledge recent epidemiological changes of these vaccine-preventable serogroups.

Characteristics of Meningococcal Invasive Disease in Neonates and Virulence of the Corresponding Isolates

BACKGROUND

The highest incidence of invasive meningococcal disease (IMD) is observed in infants. However, its prevalence in neonates (≤28 days of age) and the characteristics of the corresponding isolates are less described. This report aimed to analyze meningococcal isolates from neonates.

METHODS

We first screened the database of the national reference center for meningococci in France for confirmed neonatal IMD cases between 1999 and 2019. We then performed whole-genome sequencing on all cultured isolates, and we evaluated their virulence in a mouse model.

RESULTS

Fifty-three neonatal cases of IMD (mainly bacteremia) were identified (50 culture-confirmed cases and 3 PCR-confirmed cases) of a total of 10,149 cases (0.5%) but represented 11% of cases among infants of under 1 year of age. Nine cases (17%) occurred among neonates of 3 days of age and younger (early onset). The neonate isolates were often of serogroup B (73.6%) and belonged to the clonal complex CC41/44 (29.4%) with at least 68.5% of coverage by vaccines against serogroup B isolates. The neonatal isolates were able to infect mice although to variable levels.

CONCLUSION

IMD in neonates is not rare and can be of early or late onsets suggesting that anti-meningococcal vaccination can target women planning to have a baby.

Invasive Meningococcal Disease and Meningococcal Serogroup B Vaccination in Adults and Their Offspring: Knowledge, Attitudes, and Practices in Italy (2019)

Despite its effectiveness in preventing invasive meningococcal disease (IMD), pediatric uptake of recombinant meningococcal vaccination for serogroup B meningitis (MenB) is low in Italy. This study aimed to investigate knowledge, attitudes, and practice (KAP) about IMD and the vaccine uptake for MenB from July to December 2019, in a sample collected from a series of local Facebook discussion groups from the provinces of Parma and Reggio Emilia (North-Eastern Italy; 337,104 registered users). A self-administered anonymous web-based questionnaire was used to collect demographics, knowledge status, perceived risk for contracting meningitis, attitude towards the utility of meningococcal vaccine, and willingness to receive/perform MenB vaccine in their offspring. In total, 541 parents returned a fully completed questionnaire (response rate of 1.6% of potential recipients), with a mean age of 39.2 years ± 6.3 (78.1% females). Meningococcal infection was identified as severe or highly severe by most participants (88.9%), while it was recognized as being frequent/highly frequent in the general population by 18.6% of respondents. The overall knowledge status was unsatisfactory (57.6% ± 33.6 of correct answers to the knowledge test). Even though 63.4% of participants were somewhat favorable to MenB/MenC vaccines, offspring’s vaccination towards MenB was reported by only 38.7% of participants. In a binary logistic regression model, the male gender of respondents (adjusted odds ratio [aOR] 3.184, 95% confidence interval [95%CI] 1.772 to 5.721), living in a municipality >15,000 inhabitants (aOR 1.675, 95%CI 1.051 to 2.668), reporting a favorable attitude on meningococcus B vaccine (aOR 12.472, 95%CI 3.030 to 51.338), having been vaccinated against serogroup B (aOR 5.624, 95%CI 1.936 to 16.337) and/or serogroup C (aOR 2.652, 95%CI 1.442 to 4.872), and having previously vaccinated their offspring against serogroup C meningococcus (aOR 6.585, 95%CI 3.648 to 11.888) were characterized as positive effectors of offspring’s vaccination. On the contrary, having a higher risk perception on vaccines was identified as the only negative effector (aOR 0.429, 95%CI 0.241 to 0.765). Our results hint towards extensive knowledge gaps on IMD and preventive interventions in the general population, suggesting that a positive attitude towards vaccines and vaccinations could be identified as the main effector also for MenB acceptance. Interventions in the general population aimed at improving confidence, compliance, and acknowledgment of the collective responsibility, as well as preventing actual constraints and the sharing of false beliefs on infectious diseases and their preventive measures, could therefore increase vaccination acceptance in both targeted individuals and their offspring.

Epidemiology and Clinical Burden of Meningococcal Disease in France: Scoping Review

Invasive meningococcal disease (IMD) remains a significant health concern due to its unpredictable nature and its rapid progression. Even if occurrence of IMD is strictly monitored by a national surveillance network, no information on long-term sequelae is reported, making it difficult to assess the entire clinical burden of IMD in France. The aim of this scoping review was to analyze the epidemiology and the clinical burden of IMD in France by reporting the main epidemiological parameters, and by describing the clinical consequences and the care pathway of patients. The process of the review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension to the Scoping Reviews guidelines. In France, the incidence of IMD cases has been fluctuating over time, characterized by an overall downward trend linked to a decrease in Sg B cases and the introduction of mandatory vaccination against Sg C. Sg W cases increased in recent years (from 5% to 21% in 2019). The case fatality rate remained constant (6-12.9%). The most frequently reported sequelae were severe neurological disorder, epilepsy, and anxiety. However, data on sequelae and care pathways were scarce. Further research should concentrate on providing robust identification of sequelae and the subsequent impact on quality of life, as well as on the organization of optimal care and support for patients and their families.

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.

Immunogenicity and safety of the meningococcal B recombinant (4CMenB) vaccine in allogeneic hematopoietic cell transplantation recipients

OBJECTIVES

Despite a high risk of invasive meningococcal (Men) disease, there is no published data on any MenB vaccine after hematopoietic cell transplantation (HCT). We investigated the immunogenicity and safety of the 4CMenB recombinant vaccine (Bexsero®) in adult HCT recipients.

METHODS

Patients were eligible from 6 months post-HCT to receive 2 4CMenB doses at 2 months interval. Sera were collected at baseline, 1 month after the second dose, and 12 months after enrollment. The serum bactericidal activity (SBA) using human complement (hSBA) was assessed against fHbp, NadA, PorAP1.4 and NHBA antigens. The vaccine response was defined by one criteria for one vaccine antigen: (1) In patients with a hSBA titer < 4 at baseline: a titer > 4; (2) In patients with a hSBA titer > 4 at baseline: at least a x4 increase.

RESULTS

40 patients were included at a median of 2.14 (0.57-13.03) years post-transplant. At baseline, most patients (32/40 80%) had hSBA titers < 4 for all vaccine antigens. After 2 vaccine doses, the proportion of patients with a titer > 4 was significantly increased for fHbp (23/40 57.5%), NadA (25/40 62.5%), and PorA (31/40 77.5%) but not for NHBA for which only 6/40 (15%) patients responded. 36/40 (90%) patients were responders to > 1 antigen. However, 9 months later, only 23/37 (62.2%) patients were still seroprotected. No severe adverse event was observed.

CONCLUSION

The response rate of 90% for >1 vaccine antigen and our safety data supports the 4CMenB vaccination of HCT recipients from 6 months after transplant with 2 doses.

CLINICAL TRIALS REGISTRATION

Clinicaltrials.gov, NCT03509051.

Impact of mandatory vaccination against serogroup C meningococci in targeted and non-targeted populations in France

Since January 2018, mandatory vaccination against meningococci serogroup C has been implemented in France for children <2 years with a recommended catch-up vaccination until the age of 24 years. We aimed to analyse the impact of mandatory vaccination on populations not targeted by it (2–24 years old). We used the database of the national reference centre for meningococci to collect the number of invasive meningococcal disease (IMD) cases before (2016–2017) and after (2018–2019) the mandatory vaccination. The cultured isolates were sequenced and submitted for genomic comparison. The total number of cases was 1706, including 376 cases of IMD serogroup C. Mandatory vaccination correlated with a significant decrease among the <2 years old and a decreasing trend among the 2–14 years old group but not among 15–25 years of age. This observation may be explained by the vaccine coverage that is still low among adolescents and young adults. Moreover, the genomic analysis revealed the co-circulation of two major genotypes belonging to the clonal complex ST-11 whose distribution differed across the age groups in accord with cyclic variations of genotypes. It is important to increase specific knowledge on meningococcal epidemiology and vaccination to involve them in establishing the vaccination strategy.

One-Year Sequelae and Quality of Life in Adults with Meningococcal Meningitis: Lessons from the COMBAT Multicentre Prospective Study

INTRODUCTION

COMBAT is a prospective, multicentre cohort study that enrolled consecutive adults with community-acquired bacterial meningitis (CABM) in 69 participating centres in France between February 2013 and July 2015 and followed them for 1 year.

METHODS

Patients aged at least 18 years old, hospitalised with CABM were followed during their hospitalisation and then contacted by phone 12 months after enrolment. Here we present the prevalence of sequelae at 12 months in a subgroup of patients with meningococcal meningitis.

RESULTS

Five of the 111 patients with meningococcal meningitis died during initial hospitalisation and two died between discharge and 12 months, leaving 104 patients alive 1 year after enrolment, 71 of whom provided 12-month follow-up data. The median age was 30.0 years and 54.1% of the patients had no identified risk factor for meningitis. More than 30% reported persistent headache, more than 40% were not satisfied with their sleep and 10% had concentration difficulties. Hearing loss was present in about 15% of the patients and more than 30% had depressive symptoms. About 13% of the patients with a previous professional activity had not resumed work. On the SF-12 Health Survey, almost 50% and 30% had physical component or mental component scores lower than the 25th percentile of the score distribution in the French general population. There was a non-significant improvement in the patients' disability scores from hospital discharge to 12 months (p = 0.16), but about 10% of the patients had residual disability.

CONCLUSIONS

Although most patients in our cohort survive meningococcal meningitis, the long-term burden is substantial and therefore it is important to ensure a prolonged follow-up of survivors and to promote preventive strategies, including vaccination.

TRIAL REGISTRATION

ClinicalTrial.Gov identification number NCT01730690.

Long-term impact of invasive meningococcal disease in children: SEINE study protocol

Introduction

Invasive meningococcal disease (IMD) is still an important cause of mortality in children and survivors can have significant long-term disabling sequelae. There are few prospective studies looking at the long term neuropsychological and developmental consequences of IMD in surviving children, and the rate of sequelae may be underestimated. The SEINE study aims to have a more reliable estimate of the real rate of sequelae by assessing the long-term physical, neuropsychological, learning disorders and sensory sequelae of IMD in children and adolescents and by assessing the post-traumatic stress in parents.

Methods and analysis

The SEINE study is a multicentre, prospective, non-randomized, interventional study based on the French bacterial meningitis surveillance network. The study will include 100 children aged from birth to 15 years old, hospitalized in a Paris area paediatric ward for a meningococcal meningitis or a purpura fulminans between 2010 and 2019. The first outcome will assess long-term sequelae (physical, neurological, or sensory) measured by a general clinical and neurological examination, a neurocognitive assessment, learning development, a pure tone audiometry and an ophthalmic examination. The second outcome will assess the long-term post-traumatic stress in parents measured by the Impact of Event Scare Revised questionnaire.

Perspectives

By providing a better estimation of the rate of sequelae in children and offering an adapted follow-up of these children, we believe that the SEINE study will help to improve the management of patients surviving IMD.

Trial registration number

NCT04685850.

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.

Invasive meningococcal disease in older adults in North America and Europe: is this the time for action? A review of the literature

BACKGROUND

Neisseria meningitidis is an encapsulated Gram-negative diplococcus that asymptomatically colonises the upper respiratory tract in up to 25% of the population (mainly adolescents and young adults). Invasive meningococcal disease (IMD) caused by Neisseria meningitidis imposes a substantial public health burden,. The case fatality rate (CFR) of IMD remains high. IMD epidemiology varies markedly by region and over time, and there appears to be a shift in the epidemiology towards older adults. The objective of our review was to assess the published data on the epidemiology of IMD in older adults (those aged ≥ 55 years)in North America and Europe. Such information would assist decision-makers at national and international levels in developing future public health programmes for managing IMD.

METHODS

A comprehensive literature review was undertaken on 11 August 2020 across three databases: EMBASE, Medline and BIOSIS. Papers were included if they met the following criteria: full paper written in the English language; included patients aged ≥ 56 years; were published between 1/1/2009 11/9/2020 and included patients with either suspected or confirmed IMD or infection with N. meningitidis in North America or Europe. Case studies/reports/series were eligible for inclusion if they included persons in the age range of interest. Animal studies and letters to editors were excluded. In addition, the websites of international and national organisations and societies were also checked for relevant information.

RESULTS

There were 5,364 citations identified in total, of which 76 publications were included in this review. We identified that older adults with IMD were mainly affected by serogroups W and Y, which are generally not the predominant strains in circulation in most countries. Older adults had the highest CFRs, probably linked to underlying comorbidities and more atypical presentations hindering appropriate timely management. In addition, there was some evidence of a shift in the incidence of IMD from younger to older adults.

CONCLUSIONS

The use of meningococcal vaccines that include coverage against serogroups W and Y in immunization programs for older adults needs to be evaluated to inform health authorities' decisions of the relative benefits of vaccination and the utility of expanding national immunization programmes to this age group.

Overview of meningococcal epidemiology and national immunization programs in children and adolescents in 8 Western European countries

BACKGROUND

In Europe, meningococcal (Men) vaccines are available against 5 of the 6 serogroups responsible of nearly all cases of invasive meningococcal disease (IMD). Meningococcal vaccination has been introduced in the national immunization programs (NIPs) for children and adolescents of numerous European countries, but with no consistent strategy across countries.

OBJECTIVES

To describe IMD epidemiology, NIPs, and vaccination coverage rates (VCRs) in children and adolescents in 8 Western European countries.

METHODS

Epidemiological data (from 1999 to 2019), NIPs regarding meningococcal vaccination status, and VCRs were collected from the European Centre for Disease Prevention and Control (ECDC) and/or national websites.

RESULTS

MenB was the most common serogroup. In Belgium, Spain, France, the Netherlands, the United Kingdom (UK), and Portugal, incidence was greater for MenW than MenC. In 2019, MenB risk was covered in 2 countries (Italy, UK). MenC risk was covered in all countries, via MenC only (countries: N = 3), MenACWY only (N = 2), or MenC (infants/children) and MenACWY (adolescents) (N = 3) vaccination. VCRs were higher in children than adolescents.

CONCLUSION

Our study confirmed the diversity of NIPs, including in neighboring European countries with similar factors like economic resources and epidemiological risk, thus indicating that other factors underlie NIPs. Convergence toward a more common immunization program including MenACWY and MenB vaccination would promote equity and safe travel regarding infectious diseases for young people, and possibly improve the understanding of vaccination by patients and healthcare professionals.

Evolution of strain coverage by the multicomponent meningococcal serogroup B vaccine (4CMenB) in France

The 4CMenB, a protein-based vaccine, was licensed in Europe in 2013 against invasive meningococcal disease caused by serogroup B and is currently implemented in several countries although according to different national strategies. Isolate coverage estimation is required as vaccine-targeted antigens may vary among isolates over time. Several phenotypic and genotypic methods have been developed to predict strain coverage by scoring the expression and cross-reactivity of vaccine antigens using the Meningococcal Antigen Typing system (MATS), by the genetic correlation of alleles encoding these antigens and MATS expression data (gMATS) and by the Meningococcal Deduced Vaccine Antigen Reactivity (MenDeVAR). We applied these approaches on meningococcal B isolates in France and compared two epidemiological years, 2013-2014 and 2018-2019. A strong correlation was observed between MATS data that were generated for the year 2013-2014 and the gMATS data extracted from whole genome sequencing. gMATS and MenDeVAR were next used to compare the two years. Using gMATS, the overall coverage was 77.2% (lower limit (LL)-upper limit (UL) 66.7-87.7) and 70.7% (LL-UL 61.5-80.0) for the two years, respectively. The reduction in coverage between the two years is mainly driven by the reduction of alleles exactly matching the vaccine antigens. A high number of unpredictable isolates was observed using the MenDeVAR and was due to lack of MATS information for new or rare alleles in particular for the year 2018-2019. Our data underline the need of continuous surveillance of strain coverage and the importance of generating phenotypic MATS data to update the genetic approaches of prediction.

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.

Epidemiological profile of Neisseria meningitidis in Casablanca, Morocco: 2010-2019

Surveillance of invasive meningococcal diseases (IMD) must be carried out regularly and continuously in order to detect the emergence of strains of reduced susceptibility to antibiotics for therapeutic and prophylactic use and the appearance of new invasive clones. Molecular-typing approaches allow reliable traceability and powerful epidemiological analysis. This is an epidemiological study of Neisseria meningitidis causing meningitis in Casablanca, Morocco. The grouping was confirmed by PCR mainly on the isolates from cerebrospinal fluid (CSF). A total of 245 confirmed isolates of N .meningitidis were obtained between 2010 and 2019 of which 93 % are of group B. Overall, 24 % of all the isolates have a reduced susceptibility to penicillin G, but no resistance to penicillin G has been reported. All the isolated strains are susceptible to third-generation cephalosporins (3GCs). Genotyping by multilocus sequence typing (MLST) of a selection of 18 strains showed that the majority of isolates belong to the invasive clonal complex CC 32(9/18) followed by the CC 41/44(3/18).

Herd Protection against Meningococcal Disease through Vaccination

Reduction in the transmission of Neisseria meningitidis within a population results in fewer invasive disease cases. Vaccination with meningococcal vaccines composed of high weight capsular polysaccharide without carrier proteins has minimal effect against carriage or the acquisition of carriage. Conjugate vaccines, however, elicit an enhanced immune response which serves to reduce carriage acquisition and hinder onwards transmission. Since the 1990s, several meningococcal conjugate vaccines have been developed and, when used in age groups associated with higher carriage, they have been shown to provide indirect protection to unvaccinated cohorts. This herd protective effect is important in enhancing the efficiency and impact of vaccination. Studies are ongoing to assess the effect of protein-based group B vaccines on carriage; however, current data cast doubt on their ability to reduce transmission.

Vaccines against Meningococcal Diseases

Neisseria meningitidis is the main cause of meningitis and sepsis, potentially life-threatening conditions. Thanks to advancements in vaccine development, vaccines are now available for five out of six meningococcal disease-causing serogroups (A, B, C, W, and Y). Vaccination programs with monovalent meningococcal serogroup C (MenC) conjugate vaccines in Europe have successfully decreased MenC disease and carriage. The use of a monovalent MenA conjugate vaccine in the African meningitis belt has led to a near elimination of MenA disease. Due to the emergence of non-vaccine serogroups, recommendations have gradually shifted, in many countries, from monovalent conjugate vaccines to quadrivalent MenACWY conjugate vaccines to provide broader protection. Recent real-world effectiveness of broad-coverage, protein-based MenB vaccines has been reassuring. Vaccines are also used to control meningococcal outbreaks. Despite major improvements, meningococcal disease remains a global public health concern. Further research into changing epidemiology is needed. Ongoing efforts are being made to develop next-generation, pentavalent vaccines including a MenACWYX conjugate vaccine and a MenACWY conjugate vaccine combined with MenB, which are expected to contribute to the global control of meningitis.

Targeted vaccination campaigns of teenagers after two clusters of B invasive meningococcal disease in Brittany, France, 2017

Background

In December 2016, three cases of serogroup B invasive meningococcal disease, including two children from the same middle school (11 to 15 years old pupils), occurred in the department (administrative district) Côtes-d’Armor (Brittany, France). They were infected by a rare strain (B:P1.7–2,4:F5–9:cc162), covered by the 4CMenB vaccine (Bexsero®). Four months later, two cases due to the same strain occurred in a high school in the same area (15 to 19 years old students). In accordance with French recommendations, vaccination was proposed to students of both schools and to all individuals aged 11–19 years living or studying in the hyperendemic area. We describe these vaccination campaigns, from the alert to the impact evaluation.

Methods

The target population included 8884 people: 579 in the middle school, 2007 in the high school and 6298 in the community. In both schools, vaccination sessions were organized directly on site. In the community, teenagers were vaccinated by general practitioners. The vaccination campaign took place from May to October 2017. An active pharmacovigilance follow-up was set up to document adverse effects of the vaccine.

Results

Considering the whole target population, the vaccination coverage was estimated at 43% for 1 dose and 34% for 2 doses. Higher vaccination coverage was observed in the schools (79% in the middle school and 42% in the high school for 2 doses) than in the community (27% for 2 doses). The reported adverse effects were consistent with the safety profile of the vaccine and no severe adverse effect was reported.

Conclusions

This vaccination campaign was the third one implemented with Bexsero® in France and constitutes a reproducible approach for future targeted vaccination campaigns. No additional cases of the same strain have occurred since the end of the campaigns in the area.

Assessment of the impact of the extension of vaccination mandates on vaccine coverage after 1 year, France, 2019

One year after the extension of the childhood vaccination mandates to the 11 routine vaccinations for children under 2 years old, we estimated vaccination coverage through vaccine reimbursement data. Coverage for children born in 2018 has notably increased. Moreover, vaccine coverage for children and for vaccines not concerned by the law have also shown an increasing trend, supporting a positive impact of the ongoing communication strategy on vaccination, beyond the extension of vaccination mandates.

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.

The everchanging epidemiology of meningococcal disease worldwide and the potential for prevention through vaccination

Neisseria meningitidis is a major cause of bacterial meningitis and septicaemia worldwide and is associated with high case fatality rates and serious life-long complications among survivors. Twelve serogroups are recognised, of which six (A, B, C, W, X and Y) are responsible for nearly all cases of invasive meningococcal disease (IMD). The incidence of IMD and responsible serogroups vary widely both geographically and over time. For the first time, effective vaccines against all these serogroups are available or nearing licensure. Over the past two decades, IMD incidence has been declining across most parts of the world through a combination of successful meningococcal immunisation programmes and secular trends. The introduction of meningococcal C conjugate vaccines in the early 2000s was associated with rapid declines in meningococcal C disease, whilst implementation of a meningococcal A conjugate vaccine across the African meningitis belt led to near-elimination of meningococcal A disease. Consequently, other serogroups have become more important causes of IMD. In particular, the emergence of a hypervirulent meningococcal group W clone has led many countries to shift from monovalent meningococcal C to quadrivalent ACWY conjugate vaccines in their national immunisation programmes. Additionally, the recent licensure of two protein-based, broad-spectrum meningococcal B vaccines finally provides protection against the most common group responsible for childhood IMD across Europe and Australia. This review describes global IMD epidemiology across each continent and trends over time, the serogroups responsible for IMD, the impact of meningococcal immunisation programmes and future needs to eliminate this devastating disease.

Epidemiology of Community-Onset Severe Bacterial Infections in Children and Its Evolution: A Population-Based Study in France

OBJECTIVES

To describe the epidemiology of community-onset severe bacterial infections in children and its recent evolution.

DESIGN

Prospective, observational, population-based study from 2009 to 2014.

SETTING

An administrative area accounting for 13% of the French pediatric population.

PATIENTS

All children 1 month to 16 years old who died before admission or were admitted to a PICU for a community-onset severe bacterial infection.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The incidence and mortality rate of community-onset severe bacterial infections were compared with data from a reference population-based study conducted between 2000 and 2006, that is, before national recommendations for antimeningococcal C and antipneumococcal generalized vaccinations. Among the 261 children included (median age 25 mo), 28 (10.7%) died. The main diagnoses were meningitis (n = 85; 32%) and purpura fulminans (n = 59; 22%). The most common isolated bacteria were Neisseria meningitidis (n = 75; 29%), including 47 (63%) cases of serogroup B and 15 (20%) serogroup C, Streptococcus pneumoniae (n = 49, 19%), and Staphylococcus aureus (n = 15; 6%). The incidence of community-onset severe bacterial infections was three per 100,000 person-years (95% CI, 2.6-3.3) and had decreased by 53% from the reference period. Mortality rate was 0.3 per 100,000 person-years (95% CI, 0.2-0.4) and had decreased by 73% from the reference period. The incidence of community-onset severe bacterial infections caused by N. meningitidis and S. pneumoniae was 0.8 and 0.5 per 100,000 person-years and had decreased by 70% and 67% from the reference period. The incidence of community-onset severe bacterial infections-related to Staphylococcus aureus was 0.16 per 100,000 person-years and had increased by 220% from the reference period.

CONCLUSIONS

The incidence and mortality rate of community-onset severe bacterial infections, except for S. aureus infection, have decreased in France. N. meningitidis and S. pneumoniae continue to account for many infections, which indicates the need for better vaccination coverage and spectrum.

Serogroup C Neisseria meningitidis disease epidemiology, seroprevalence, vaccine effectiveness and waning immunity, England, 1998/99 to 2015/16

Background

In 1999, the United Kingdom (UK) was the first country to introduce meningococcal group C (MenC) conjugate vaccination. This vaccination programme has evolved with further understanding, new vaccines and changing disease epidemiology.

Aim

To characterise MenC disease and population protection against MenC disease in England.

Methods

Between 1998/99–2015/16, surveillance data from England for laboratory-confirmed MenC cases were collated; using the screening method, we updated vaccine effectiveness (VE) estimates. Typing data and genomes were obtained from the Meningitis Research Foundation Meningococcus Genome Library and PubMLST Neisseria database. Phylogenetic network analysis of MenC cc11 isolates was undertaken. We compared bactericidal antibody assay results using anonymised sera from 2014 to similar data from 1996–1999, 2000–2004 and 2009.

Results

MenC cases fell from 883 in 1998/99 (1.81/100,000 population) to 42 cases (0.08/100,000 population) in 2015/16. Lower VE over time since vaccination was observed after infant immunisation (p = 0.009) and a single dose at 1–4 years (p = 0.03). After vaccination at 5–18 years, high VE was sustained for ≥ 8 years; 95.0% (95% CI: 76.0– 99.5%). Only 25% (75/299) children aged 1–14 years were seroprotected against MenC disease in 2014. Recent case isolates mostly represented two cc11 strains.

Conclusion

High quality surveillance has furthered understanding of MenC vaccines and improved schedules, maximising population benefit. The UK programme provides high direct and indirect protection despite low levels of seroprotection in some age groups. High-resolution characterisation supports ongoing surveillance of distinct MenC cc11 lineages.

Transmissibility and pathogenicity of the emerging meningococcal serogroup W sequence type-11 complex South American strain: a mathematical modeling study

BACKGROUND

The recent emergence of strains belonging to the meningococcal serogroup W (MenW) sequence type-11 clonal complex and descending from the South American sub-lineage (MenW:cc11/SA) has caused significant shifts in the epidemiology of meningococcal disease worldwide. Although MenW:cc11/SA is deemed highly transmissible and invasive, its epidemiological characteristics have not yet been quantified.

METHODS

We designed a mathematical model of MenW transmission, carriage, and infection to analyze the recent epidemiology of invasive disease caused by MenW:cc11/SA strains and by other MenW strains in England and in France. We confronted that model with age-stratified incidence data to estimate the transmissibility and the invasiveness of MenW:cc11/SA in England, using the data in France as a validation cohort.

RESULTS

During the epidemiological years 2010/2011-2014/2015 in England, the transmissibility of MenW:cc11/SA relative to that of other MenW strains was estimated at 1.20 (95% confidence interval, 1.15 to 1.26). The relative invasiveness of MenW:cc11/SA was also found to exceed unity and to increase with age, with estimates ranging from 4.0 (1.6 to 9.7) in children aged 0-4 years to 20 (6 to 34) in adults aged ≥ 25 years. In France, the model calibrated in England correctly reproduced the early increase of MenW:cc11/SA disease during 2012/2013-2016/2017. Most recent surveillance data, however, indicated a decline in MenW:cc11/SA disease. In both countries, our results suggested that the transmission of MenW:cc11/SA carriage possibly started several months before the first reported case of MenW:cc11/SA disease.

DISCUSSION

Our results confirm earlier suggestions about the transmission and the pathogenic potential of MenW:cc11/SA. The main limitation of our study was the lack of age-specific MenW carriage data to confront our model predictions with. Furthermore, the lesser model fit to the most recent data in France suggests that the predictive accuracy of our model might be limited to 5-6 years.

CONCLUSIONS

Our study provides the first estimates of the transmissibility and of the invasiveness of MenW:cc11/SA. Such estimates may be useful to anticipate changes in the epidemiology of MenW and to adapt vaccination strategies. Our results also point to silent, prolonged transmission of MenW:cc11/SA carriage, with potentially important implications for epidemic preparedness.

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.

Characterization of invasive Neisseria meningitidis isolates recovered from children in Turkey during a period of increased serogroup B disease, 2013-2017

Diverse Neisseria meningitidis strains belonging to various serogroups and clonal complexes cause epidemic and endemic life-threatening disease worldwide. This study aimed to investigate the genetic diversity of recent invasive meningococci in Turkey with respect to multilocus sequence type (MLST) and also meningococcal serogroup B (MenB) vaccine antigens to enable assessment of potential MenB strain coverage using the genetic Meningococcal Antigen Typing System (gMATS). Fifty-four isolates, representing 37.5% of all pediatric (ages 0-18 years) invasive meningococcal disease cases in Turkey from January 2013 to December 2017, underwent genome sequence analysis. Thirty-six (66.7%) isolates were MenB, 10 (18.5%) were serogroup W (MenW), 4 (7.4%) were serogroup A (MenA), 3 (5.6%) were serogroup Y (MenY) and 1 (1.8%) was serogroup X (MenX). The MenB isolates were diverse with cc35 (19.4%), cc41/44 (19.4%) and cc32 (13.8%) as the most prevalent clonal complexes. The MenW isolates (n = 10) comprised cc11 (n = 5), ST-2754 (cc-unassigned; n = 4) and cc22 (n = 1). gMATS was indicative of high 4CMenB coverage (72.2-79.1%) of Turkish invasive MenB strains from pediatric patients. Strain coverage of several clonal complexes differed from that seen elsewhere in Europe highlighting the importance of performing local assessments and also the use of phenotypic methods, i.e. MATS, where possible. All of the isolates possessed in-frame fhbp alleles and so were potentially covered by MenB-fHbp. Continued surveillance is essential to guide recommendations for current and future vaccines as well as understanding changes in epidemiology.

Diversity of meningococci associated with invasive meningococcal disease in the Republic of Ireland over a 19 year period, 1996-2015

This study examined the capsular phenotype and genotype of invasive meningococcal disease (IMD)-associated Neisseria meningitidis recovered in the Republic of Ireland (RoI) between 1996 and 2015. This time period encompasses both pre- (when IMD was hyperendemic in the RoI) and post- meningococcal serogroup C conjugate (MCC) vaccine introduction. In total, 1327 isolates representing over one-third of all laboratory-confirmed cases of IMD diagnosed each epidemiological year (EY), were characterised. Serogroups B (menB) and C (menC) predominated throughout, although their relative abundance changed; with an initial increase in the proportion of menC in the late 1990s followed by their dramatic reduction post-MCC vaccine implementation and a concomitant dominance of menB, despite an overall decline in IMD incidence. While the increase in menC was associated with expansion of specific clonal-complexes (cc), cc11 and cc8; the dominance of menB was not. There was considerable variation in menB-associated cc with declines in cc41/44 and cc32, and increases in cc269 and cc461, contributing to a significant increase in the clonal diversity of menB isolates over the study. This increase in diversity was also displayed among the serosubtyping data, with significant declines in proportions of menB isolates expressing p1.4 and p1.15 antigens. These data highlight the changing diversity of IMD-associated meningococci since 1996 in the RoI and emphasise the need for on-going surveillance particularly in view of the recent introduction of a menB vaccine.

Emergence of new genetic lineage, ST-9316, of Neisseria meningitidis group W in Hauts-de-France region, France 2013-2018

BACKGROUND

The epidemiology of invasive meningococcal disease (IMD) is continuously changing in incidence, age distribution and/or the expansion of new strains of Neisseria meningitidis. The epidemiology of IMD due to group W (IMDW) has changed recently at a global level with the emergence of isolates belonging to the clonal complex ST-11 (CC11) derived from the South America-UK strain. A more recent change has been detected in France with the emergence of a new genotype distinct from CC11 that we aimed to analyse.

METHODS

Epidemiological and microbiological surveillance data in France were used in combination with whole genome sequencing (WGS) to detect emerging phenotypes and genotypes of IMD causing strains, and their susceptibility to immunity induced by the 4CMenB vaccine. Transgenic mice expressing the human transferrin were used to analyse the virulence of emerging strain isolates by direct comparison with CC11 isolates.

FINDINGS

Our data showed a local increase of IMDW isolates in north France since 2013. The isolates belonged to ST-9316 and few were ST-11 isolates. WGS clustered ST-9316 isolates together and were distantly separated from the isolates of the clonal complex ST-11 (CC11). Unlike cases due to W/CC11 isolates, cases due to W/ST-9316 isolates were mostly observed amongst infants under the age of 1 year but with lower mortality compared to W/CC11 cases. Genomic comparison showed that the W/ST-9316, unlike W/CC11 isolates, lacked the hmbR gene encoding the haemoglobin receptor that is a virulence factor involved in the acquisition of iron from haemoglobin. W/ST-9316 further showed lower virulence in mice compared to W/CC11 isolates.

INTERPRETATION

We report the emergence of a novel sequence type (ST-9316) mostly associated with serogroup W, and exhibiting a lower virulence and a distinct age specific incidence profile than W/CC11 isolates. Surveillance requires powerful approaches combining WGS and pathophysiological analysis to adapt control measures.

Unusual Initial Abdominal Presentations of Invasive Meningococcal Disease

Background

Invasive meningococcal disease (IMD) is recognized as septicemia and/or meningitis. However, early symptoms may vary and are frequently nonspecific. Early abdominal presentations have been increasingly described. We aimed to explore a large cohort of patients with initial abdominal presentations for association with particular meningococcal strains.

Methods

Confirmed IMD cases in France between 1991 and 2016 were screened for the presence within the 24 hours before diagnosis of at least 1 of the following criteria (1) abdominal pain, (2) gastroenteritis with diarrhea and vomiting, or (3) diarrhea only. Whole-genome sequencing was performed on all cultured isolates.

Results

We identified 105 cases (median age, 19 years) of early abdominal presentations with a sharp increase since 2014. Early abdominal pain alone was the most frequent symptom (n = 67 [64%]), followed by gastroenteritis (n = 26 [25%]) and diarrhea alone (n = 12 [11%]). Twenty patients (20%) had abdominal surgery. A higher case fatality rate (24%) was observed in these cases compared to 10.4% in all IMD in France (P = .007) with high levels of inflammation markers in the blood. Isolates of group W were significantly more predominant in these cases compared to all IMD. Most of these isolates belonged to clonal complex 11 of the sublineages of the South American-UK strain.

Conclusions

Abdominal presentations are frequently provoked by hyperinvasive isolates of meningococci. Delay in the management of these cases and the virulence of the isolates may explain the high fatality rate. Rapid recognition is a key element to improve their management.

Community outbreak of serogroup B invasive meningococcal disease in Beaujolais, France, February to June 2016: from alert to targeted vaccination

In February and March 2016, four cases of serogroup B invasive meningococcal disease (IMD) occurred over 3 weeks in a small area north of Lyon in the Auvergne-Rhône-Alpes region, France. There were no deaths but two cases had sequelae. This community outbreak was caused by a rare meningococcal strain of the clonal complex ST-32, covered by the 4CMenB/Bexsero vaccine. The incidence rate for serogroup B IMD in this area was 22.5 per 100,000 inhabitants, which is above the epidemic threshold (10/100,000). The number of cases observed was significantly higher than expected in the age group of 0–24 year-olds (standardised incidence ratio: 96). These results suggested the potential emergence of this invasive strain in this sub-population. In accordance with French recommendations, it was decided to vaccinate the population aged between 2 months and 24 years, living, working or studying in the epidemic area. The vaccination campaign took place from April to September 2016. Vaccination coverage was estimated at 47% for one dose and 40% for two doses. The lowest coverage estimations were observed for the age groups younger than 3 and 15–19 years. Enhanced epidemiological and microbiological surveillance reported a fifth case in June 2016, outside the epidemic area.

Study of the Immune Response in the Elderly: Is It Necessary to Develop a Vaccine against Neisseria meningitidis for the Aged?

Literature reports the association between aging and decline in the immune system function. The elderly have a higher risk of developing infectious diseases and are often less responsive to vaccines that are effective in the young. The case fatality rate of invasive meningococcal disease is higher in the elderly; therefore, vaccination for this population should be evaluated. Although new vaccines have been developed against Neisseria meningitidis, there is still a need to evaluate a vaccine for those older than 60 years, as the currently licensed vaccines are not indicated for this population.

Clinical and Genetic Spectrum of a Large Cohort With Total and Sub-total Complement Deficiencies

The complement system is crucial for defense against pathogens and the removal of dying cells or immune complexes. Thus, clinical indications for possible complete complement deficiencies include, among others, recurrent mild or serious bacterial infections as well as autoimmune diseases (AID). The diagnostic approach includes functional activity measurements of the classical (CH50) and alternative pathway (AP50) and the determination of the C3 and C4 levels, followed by the quantitative analysis of individual components or regulators. When biochemical analysis reveals the causal abnormality of the complement deficiency (CD), molecular mechanisms remains frequently undetermined. Here, using direct sequencing analysis of the coding region we report the pathogenic variants spectrum that underlie the total or subtotal complement deficiency in 212 patients. We identified 107 different hemizygous, homozygous, or compound heterozygous pathogenic variants in 14 complement genes [C1Qβ (n = 1), C1r (n = 3), C1s (n = 2), C2 (n = 12), C3 (n = 5), C5 (n = 12), C6 (n = 9), C7 (n = 17), C8 β (n = 7), C9 (n = 3), CFH (n = 7), CFI (n = 18), CFP (n = 10), CFD (n = 2)]. Molecular analysis identified 17 recurrent pathogenic variants in 6 genes (C2, CFH, C5, C6, C7, and C8). More than half of the pathogenic variants identified in unrelated patients were also found in healthy controls from the same geographic area. Our study confirms the strong association of meningococcal infections with terminal pathway deficiency and highlights the risk of pneumococcal and auto-immune diseases in the classical and alternative pathways. Results from this large genetic investigation provide evidence of a restricted number of molecular mechanisms leading to complement deficiency and describe the clinical potential adverse events of anti-complement therapy.

Chronic meningococcemia: a report of 26 cases and literature review

Chronic meningococcemia is defined by blood culture(s) positive for Neisseria meningitidis, symptoms duration > 7 days, and neither meningitis nor shock on admission. This series of 26 consecutive cases illustrates that this is a rare disease (< 5% of meningococcemia, < 0.05 cases per 100,000 inhabitants per year), mostly affecting young adults, males, with no predisposing condition. Major symptoms include fever, rash, and arthralgia. Median time between symptoms onset, and diagnosis is 28 days. Most patients fully recover with a 1-week course of parenteral betalactams.

Delayed Generalized Necrotic Purpuric Rash in a C6-deficient 12-year-old Girl Treated for Group W Meningococcal Disease

We report an unusual case of generalized necrotic purpuric rash that started 48 hours after the initiation of effective third-generation cephalosporin therapy to treat Neisseria meningitidis W infection in a 12-year-old girl. The course was favorable with no shock, and she recovered completely without sequelae. This infection revealed C6 deficiency in our patient.

Procalcitonin and C-reactive protein may help to detect invasive bacterial infections in children who have fever without source

AIM

This study evaluated the epidemiology and performance of biomarkers for identifying bacterial infections in children who presented with fever without source.

METHODS

We conducted a prospective cohort study in the paediatric department at the University Hospital of Nantes, France, in 2016. Children older than six days and younger than five years of age were included.

RESULTS

A total of 1060 children (52.2% male) with fever without source were admitted, and the median age was 17 months (interquartile range: 6.6-24.3 months). Severe bacterial infections were diagnosed in 127 (11.9%) children and invasive bacterial infections in 11 (1.0%) children: four (0.3%) with bacterial meningitis and seven (0.6%) with bacteraemia. A further 114 (10.7%) had urinary tract infections. We explored the area under the receiver-operating characteristic curves for identifying invasive bacterial infections. The curves for procalcitonin and C-reactive protein assays were better than those for the absolute neutrophil counts and the white blood cell counts.

CONCLUSION

This study found that there was a low prevalence of invasive bacterial infections in children who presented with fever without source. It also showed that procalcitonin and C-reactive protein may help to detect invasive bacterial infections in children who have fever without source.

Impact of meningococcal C conjugate vaccination programs with and without catch-up campaigns in adolescents: Lessons learned from Bahia, Brazil

The significant increase in the incidence rates and ongoing outbreaks of serogroup C meningococcal (MenC) disease, associated with the sequence type-103 complex, motivated the incorporation of the meningococcal C conjugate (MCC) vaccine in the routine immunization program in the State of Bahia, Brazil in early 2010, targeting children younger than 5 years of age. In its capital, Salvador, the program also included a catch-up campaign for individuals 10-24 years of age. We performed an observational, ecological study, analyzing data collected from 2007 to 2015, to compare the impact of these two immunization strategies on meningococcal disease incidence and mortality rates. In Salvador, following the vaccination program, a dramatic early impact on MenC disease and mortality rates could be observed, with significant reductions in incidence rates of MenC disease in all age groups, including individuals that were too old to have been vaccinated, indicating the presence of herd protection. Compared to the pre-vaccine period, a virtual disappearance of MenC disease was observed in 2015. However, in the state of Bahia (excluding the city of Salvador), no herd protection could be observed, with significant impact only among vaccine-eligible children within 5 years of introduction of the MCC vaccination program. These results highlight the importance of catch-up campaigns, including adolescents and young adults, to induce herd protection compared to immunization strategies restricted to infants and young children. This information is crucial for identifying optimal immunization policies and future strategies, focused on adolescents, to optimize the impact of MCC vaccination programs.

Invasive Meningococcal Disease on the Workplaces: a systematic review

Background and aims of the work: Invasive Meningococcal Disease (IMD) represents a global health threat, and occupational settings have the potential to contribute to its spreading. Therefore, here we present the available evidences on the epidemiology of IMD on the workplaces.

METHODS

The following key words were used to explore PubMed: Neisseria meningitidis, meningococcus, meningococcal, invasive meningococcal disease, epidemiology, outbreaks, profession(al), occupation(al).

RESULTS

We identified a total of 12 IMD cases among healthcare workers (HCW), 44 involving biological laboratory workers (BLW), 8 among school personnel, and eventually 27 from other settings, including 3 large industrial working populations. Eventual prognosis of BLW, particularly the case/fatality ratio, was dismal. As clustered in time and space, data about school cases as well as industrial cases seem to reflect community rather than occupational outbreaks. In general, we identified a common pattern for HCW and BLW, i.e. the exposure to droplets or aerosol containing N meningitidis in absence of appropriate personal protective equipment (PPE) and/or microbiological safety devices (MSD) (e.g. cabinets). Post-exposure chemoprophylaxis (PEC) was rarely reported by HCW (16.7%) workers, and never by BLW. Data regarding vaccination status were available only for a case, who had failed requested boosters.

CONCLUSIONS

The risk for occupational transmission of IMD appears relatively low, possibly as a consequence of significant reporting bias, with the exception of HCW and BLW. Improved preventive measures should be implemented in these occupational groups, in order to improve the strict use of PPE and MSD, and the appropriate implementation of PEC.