Invasive Meningococcal Disease Research Articles

Epidemiology of invasive meningococcal disease, Japan, 2013 to 2023.

BackgroundThe National Surveillance for Invasive Meningococcal Disease (IMD) initiative started in Japan in April 2013. Multiple international mass gathering events have since been held in Japan, and the COVID-19 pandemic has occurred.AimWe summarised 10 years of national surveillance data for IMD in Japan to describe epidemiological characteristics of IMD and evaluate the influence of mass gatherings and the COVID-19 pandemic on IMD.MethodsUpon diagnosis of IMD, patient information and specimens were collected and reported to local health centres. We analysed the epidemiology of IMD cases reported between 1 April 2013 and 31 March 2023.ResultsAmong 274 cases reported (median age: 55 years; 55% male), no outbreaks related to mass gathering events were identified. The annual reported incidence of IMD was 0.001-0.039 cases per 100,000 individuals between 2014 and 2022, with a notable decrease after 2020. The overall case fatality rate was 12% (33/274). The most frequent serogroups were Y and B (46 and 17%). Multilocus sequence typing revealed a predominance of clonal complex (cc) 23, followed by cc2057, while cc11 was detected in eight cases.ConclusionThe reported incidence of IMD in Japan is low compared with high-endemic countries and decreased further during the COVID-19 pandemic. This unique epidemiology of IMD in Japan lacks a clear explanation. However, distribution of meningococcal strains, such as predominance of serogroup Y, could be a contributing factor. Maintaining high-quality surveillance, including of serogroups and sequence types, is crucial to manage and prevent future IMD cases in Japan effectively.

The Prevalence, Serogroup Distribution and Risk Factors of Meningococcal Carriage in Children, Adolescents and Young Adults in Turkey Meningo-Carr-TR Study PART 3: COVID-19 Pandemic Situation

Background: The prevalence of meningococcal carriage and serogroup distribution is crucial for assessing the epidemiology of invasive meningococcal disease, forecasting outbreaks and formulating potential immunization strategies. Following the meningococcal carriage studies conducted in Turkey in 2016 and 2018, we planned to re-evaluate meningococcal carriage in children, adolescents and young adults during the COVID-19 pandemic period. Methods: In the MENINGO-CARR-3 study, we collected nasopharyngeal samples from 1585 participants 0–24 years of age, across 9 different centers in Turkey. We used polymerase chain reaction and serogroup distribution to determine how common it is for people to carry Neisseria meningitidis. Results: The overall meningococcal carriage rate was 8.5% (n = 134). The serogroup distribution was as follows: serogroup A, 6%; serogroup B, 30.6%; serogroup W, 12.7%; serogroup Y, 3.7%; serogroup X, 1.5% and nongroupable as 45.5%. The highest carriage rate was found in 15–17-year-old adolescents (24.1%, 17.9%, and 20.2%, respectively). The carriage rate was higher among participants who had a previous COVID-19 infection (P = 0.05; odds ratio: 1.95; 95% confidence interval: 1.11–3.44). The nasopharyngeal carriage rate was also higher than in the 2016 and 2018 studies (8.45% vs. 6.3% and 7.5%, respectively), and the most prevalent groupable serogroup was B during this study period, followed by serogroup W in 2016 and serogroup X in 2018. Conclusions: The present study found that meningococcal carriage was higher during the post-COVID-19 pandemic period, especially in adolescents and young adults. Severe acute respiratory syndrome coronavirus-2 virus itself and/or pandemic mitigation strategies may affect both meningococcal carriage and serogroup distribution. Serogroup distribution varies between years, and further immunization strategies, including adolescent immunization, may play a role in controlling invasive meningococcal disease.

Global Epidemiology of Meningococcal Disease-Causing Serogroups Before and After the COVID-19 Pandemic: A Narrative Review.

Invasive meningococcal disease (IMD) is associated with high morbidity and mortality and predominantly caused by five Neisseria meningitidis serogroups (A/B/C/W/Y). Polysaccharide conjugate vaccines induce T-cell-dependent immune responses, are immunogenic in infants and adults, and reduce carriage, and vaccination of age groups associated with high-carriage can provide indirect protection in the unvaccinated (herd immunity). Successful vaccination programs must be tailored to local epidemiology, which varies geographically, temporally, and by age and serogroup. Serogroup A IMD once predominated globally, but has largely disappeared following mass vaccination programs. Serogroup B was a predominant cause of IMD in many global regions from 2010 to 2018, typically affecting younger age groups. Spread of serogroup C clonal complex-11 IMD in the 1990s prompted implementation of MenC vaccine programs in many countries, resulting in declines in prevalence. Serogroup C still caused>20% of global IMD through the mid-2010s. Serogroup W became a significant contributor to global IMD after Hajj pilgrimage outbreaks in 2000; subsequent increases of endemic disease and outbreaks were reported pre-pandemic in many regions. Serogroup Y emerged in the 1990s as a significant cause of IMD throughout various regions and prevalence had increased or stabilized from 2010 to 2018. Serogroup X is uncommon outside the African meningitis belt, and its prevalence has declined since before the COVID-19 pandemic. Global IMD declines during the pandemic were followed by resurgences generally caused by serogroups that were prevalent pre-pandemic and affecting mainly unvaccinated age groups (particularly adolescents/young adults). Recent IMD epidemiology underscores the importance of vaccinating at-risk age groups against regionally prevalent serogroups; for example, the anti-serogroup X component of the recently prequalified MenACWXY vaccine is likely to provide limited protection outside the African meningitis belt. In other regions, comprehensive vaccination against MenB and MenACWY, which could be streamlined by the recently approved MenABCWY vaccine, seems more appropriate.

Quadrivalent Conjugate Vaccine and Invasive Meningococcal Disease in US Adolescents and Young Adults

Beginning in 2005, the US implemented routine immunization of adolescents with a quadrivalent conjugate vaccine (MenACWY) for the prevention of invasive meningococcal disease (IMD). To assess whether MenACWY immunization was associated with a reduced IMD burden among the US adolescent population and how the downward trajectory of IMD that began in the mid-1990s might have evolved in the absence of vaccination efforts. In this decision analytical study, a bayesian hierarchical Poisson regression model was developed to investigate the potential trajectory of IMD among US adolescents and young adults without vaccination and evaluate the direct association of vaccination with IMD burden. The model included the entire age-stratified US population and was fitted to national incidence data for serogroups C, W, and Y from January 1, 2001, to December 31, 2021, with stratification by vaccination status for IMD cases. Simulated counterfactual scenario of absent vaccination from 2005 to 2021, while retaining the incidence rate of IMD for unvaccinated individuals estimated during model fitting. The main outcomes were the estimated numbers of IMD cases and deaths averted by MenACWY vaccination among US adolescents and young adults aged 11 to 23 years. Among the entire US population from 2005 to 2021, MenACWY vaccination prevented an estimated 172 (95% credible interval [CrI], 85-345) cases of IMD among US adolescents 11 to 15 years of age and 328 (95% CrI, 164-646) cases of IMD among those aged 16 to 23 years. Absent vaccination, the cumulative incidence of IMD in these age groups would have been at least 59% higher than reported over the same period with vaccination. Using case fatality rates of unvaccinated individuals derived from national data, vaccination averted an estimated 16 (95% CrI, 8-31) deaths among adolescents aged 11 to 15 years and 38 (95% CrI, 19-75) deaths among those aged 16 to 23 years. This decision analytical model suggests that the MenACWY vaccination program in the US was associated with a reduced burden of meningococcal disease. Without vaccination, the incidence rates per 100 000 adolescents and young adults would have been substantially higher than those observed during the vaccine era.

Statewide Outbreak of Neisseria meningitidis Serogroup Y, Sequence Type 1466 - Virginia, 2022-2024.

Invasive meningococcal disease (IMD) is a severe illness that can have devastating effects; outbreaks are uncommon in the United States. Vaccination is the preferred control measure for IMD outbreaks when a defined population at risk (e.g., college students or persons experiencing homelessness) can be identified. In August 2022, the Virginia Department of Health (VDH) began investigating an IMD outbreak in Virginia's Eastern Health Planning Region, prompted by the detection of four confirmed cases within 8 weeks. Clinical isolates available from three cases were characterized as Neisseria meningitidis serogroup Y, sequence type 1466. A subsequent statewide investigation identified 36 genetically related cases, including seven deaths (case fatality rate=19.4%) as of March 1, 2024. A majority of patients (63.9%) were in an age group (30-60 years) not generally considered at increased risk for IMD; 78.0% were non-Hispanic Black or African American. No common exposures, affiliations, or risk factors were identified, and a defined population could not be identified for vaccination. VDH recommended quadrivalent (serogroups A, C, W, and Y) meningococcal conjugate vaccination of a subset of close contacts of patients based on IMD risk factors and age range similar to that of patients with identified cases. IMD outbreaks might affect populations without established IMD risk factors. Lack of a well-defined population at risk might prompt exploration of novel control strategies, such as selective vaccination of close contacts.

Initial Experiences with Invasive Meningococcal Disease: Insights from Survivors and Their Caregivers.

Invasive meningococcal disease (IMD) has a low incidence but is a life-threatening illness with a 10-15% mortality rate. Even with timely treatment, survivors may experience acute and long-term health complications. While meningococcal vaccines are recommended for adolescents and young adults in the USA, vaccination coverage remains uneven across serotypes. This study investigated the physical, social, psychological, and economic burden of IMD on survivors and their caregivers in the USA during the acute phase (Part1, presented in this manuscript) and the long-term phase (Part2, presented in a separate manuscript) of IMD. This study implemented a non-interventional, mixed-methods approach using a bespoke survey and qualitative interviews (designed on the basis of a preliminary conceptual model of IMD) with US survivors and their caregivers. A total of 11 survivors (1 adolescent, 10 adults) and 3 caregivers participated in the study. Survivors contracted IMD during infancy (n = 2), childhood (n = 3), or adulthood (n = 6), and often described leading healthy lives pre-IMD. At IMD onset, interactions with the healthcare system impacted participants' experiences; confusion and care delays were common, and procedures were often invasive (e.g., amputations). Survivors commonly experienced symptoms including skin rash (7/11), fever (6/11), and unconsciousness (6/11), consistent with caregivers' reports. Survivors able to report on the short-term impacts of IMD (n = 9) described functional limitations (9/9), emotional impacts (6/9) such as fear and trauma, and school (6/9), work (4/9), and financial (5/9) challenges. Caregivers also experienced emotional impacts (3/3) and family (2/3), work (3/3), and financial (3/3) impacts during the acute phase. IMD places a significant humanistic burden on survivors and their caregivers during the acute phase. Results from Part1 of this study indicate a need for increased disease awareness and healthcare provider education, expeditious diagnosis, and improved access to prevention methods such as available meningococcal vaccines. A video abstract is available with this article. Video abstract (MP4 1,24,432kb).

Life After Invasive Meningococcal Disease: Insights from Survivors and Their Caregivers.

Invasive meningococcal disease (IMD) has a low incidence but is a life-threatening illness that is preventable via vaccination. Even with treatment, up to 10-15% of cases are fatal, and many survivors may experience severe long-term sequelae. Building upon the acute-phase findings presented in the Part1 manuscript for this study, we describe the long-term physical, social, psychological, and economic burden of IMD on US survivors and their caregivers in this Part2 manuscript. This was a novel, non-interventional, mixed-methods study among US survivors and their caregivers using a bespoke survey and qualitative interviews. Ten adult survivors, one adolescent survivor, and three caregivers participated in this study. Survivors described extensive physical, neurological, and systemic sequelae, including difficulty walking (11/11), repeat secondary infections (9/11), and numbness (6/11), among others, which were echoed by caregivers. Survivors shared that IMD had negatively impacted their long-term quality of life, citing long-term impacts including emotional impacts (11/11), social impacts (10/11), memory (7/11) and attention (5/11) problems, and difficulty with functional (10/11), self-care (7/11), and physical (6/11) activities. Caregivers were also impacted, describing emotional trauma (3/3), sleep problems (2/3), and day-to-day challenges (2/3). Long-term financial challenges related to healthcare resource utilization were substantial, with specialized care and rehabilitation therapy expenses (11/11), insurance challenges (8/11), and high out-of-pocket costs (6/11) for survivors. Productivity losses were also commonly described by survivors (9/11); sequelae hindered ability to attend school (9/11) or work full time (8/11). Caregivers (2/3) described taking leave from their employment, affecting family income. The humanistic burden of IMD on survivors and their caregivers is substantial and persistent. A comprehensive approach, including preventative measures (e.g., vaccination) and long-term medical, psychological, and financial support for those affected, is needed to mitigate the burden of IMD. A video abstract is available with this article. Video abstract (MP4 1,17,430kb).

Genetic characterization of Neisseria meningitidis isolates recovered from patients with invasive meningococcal disease in Lithuania.

Neisseria meningitidis is a gram-negative bacterium responsible for life-threatening invasive infections known as invasive meningococcal disease and is associated with high fatality rates and serious lifelong disabilities among survivors. This study aimed to characterize N. meningitidis isolates cultured from blood and cerebrospinal fluid collected between 2009 and 2021 in Lithuania, assess their genomic relationships with European strains, and evaluate the possibility of using a cost-effective method for strain characterization, thus improving the national molecular surveillance of invasive meningococcal disease. In total, 321 N. meningitidis isolates were collected and analyzed using multilocus restriction typing (MLRT). Amplification of the penA gene and restriction fragment length polymorphism analysis were performed to identify the modified penA genes. Based on the MLRT genotyping results, we selected 10 strains for additional analysis using whole-genome sequencing. The sequenced genomes were incorporated into a dataset of publicly available N. meningitidis genomes to evaluate genomic diversity and establish phylogenetic relationships within the Lithuanian and European circulating strains. We identified 83 different strains using MLRT genotyping. Genomic diversity of N. meningitidis genomes analysed revealed 21 different sequence types (STs) circulating in Lithuania. Among these, ST34 was the most prevalent. Notably, three isolates displayed unique combinations of seven housekeeping genes and were identified as novel STs: ST16969, ST16901, and ST16959. The analyzed strains were found to possess virulence factors not commonly found in N. meningitidis. Six distinct penA profiles were identified, each with different frequencies. In the present study, we also identified N. meningitidis strains with new penA, NEIS0123, NEIS1320, NEIS1525, NEIS1600, and NEIS1753 loci variants. In our study, using the cgMLST scheme, Minimum Spanning Tree (MST) analysis did not identify significant geographic relationships between Lithuanian N.meningitidis isolates and strains from Europe. Discussion: To our knowledge, this is the first study to employ whole genome sequencing (WGS) method for a comprehensive genetic characterization of invasive N. meningitidis isolates from Lithuania. This approach provides a more detailed and precise analysis of genomic relationships and diversity compared to prior studies relying on traditional molecular typing methods and antigen analysis.

Inequalities in the risk and prevention of invasive meningococcal disease in the United States - A systematic literature review.

Vaccination remains the most effective strategy to prevent invasive meningococcal disease (IMD), with MenACWY, MenB and MenABCWY recommended for adolescents/young adults in the United States (US). However, vaccination coverage remains suboptimal, which could be related to population inequalities. To understand the impact of IMD risk, prevention and control inequalities, a global systematic literature review (Medline, Embase, 2012-2022) was conducted on individual, socioeconomic, and environmental inequalities associated with IMD risk, prevention and control in all ages. Studies on IMD risk (n = 15) and prevention (n = 14) inequalities were identified. IMD incidence proportions were higher in Medicaid versus commercially insured populations, and IMD mortality was higher in poorer neighborhoods. White adolescents, adolescents from lower income families, and with lower maternal education were more likely to receive MenB vaccination; while Black and Hispanic adolescents, and adolescents with higher family incomes, were more likely to receive MenACWY vaccination. Meningococcal vaccination was associated with being up-to-date with other vaccinations, having multiple healthcare/well child visits, having a pediatrician as healthcare provider (HCP), and attending private facilities; while being uninsured was associated with lower vaccination. States with a MenACWY vaccination mandate and higher pediatrician-to-children ratios had higher vaccination rates. Important inequalities were due to individual differences, socioeconomic, and environmental factors. IMD prevention is suboptimal, especially among adolescents/young adults. To improve health equity, health policy makers could ameliorate meningococcal vaccination coverage across the US, with simplified and stronger meningococcal vaccine recommendations from public health authorities, and initiatives to enhance parental/patient and HCP knowledge of IMD and vaccine recommendations.

Neisseria meningitidis activates pyroptotic pathways in a mouse model of meningitis: role of a two-partner secretion system.

There is evidence that in infected cells in vitro the meningococcal HrpA/HrpB two-partner secretion system (TPS) mediates the exit of bacteria from the internalization vacuole and the docking of bacteria to the dynein motor resulting in the induction of pyroptosis. In this study we set out to study the role of the HrpA/HrpB TPS in establishing meningitis and activating pyroptotic pathways in an animal model of meningitis using a reference serogroup C meningococcal strain, 93/4286, and an isogenic hrpB knockout mutant, 93/4286ΩhrpB. Survival experiments confirmed the role of HrpA/HrpB TPS in the invasive meningococcal disease. In fact, the ability of the hrpB mutant to replicate in brain and spread systemically was impaired in mice infected with hrpB mutant. Furthermore, western blot analysis of brain samples during the infection demonstrated that: i. N. meningitidis activated canonical and non-canonical inflammasome pyroptosis pathways in the mouse brain; ii. the activation of caspase-11, caspase-1, and gasdermin-D was markedly reduced in the hrpB mutant; iii. the increase in the amount of IL-1β and IL-18, which are an important end point of pyroptosis, occurs in the brains of mice infected with the wild-type strain 93/4286 and is strongly reduced in those infected with 93/4286ΩhrpB. In particular, the activation of caspase 11, which is triggered by cytosolic lipopolysaccharide, indicates that during meningococcal infection pyroptosis is induced by intracellular infection after the exit of the bacteria from the internalizing vacuole, a process that is hindered in the hrpB mutant. Overall, these results confirm, in an animal model, that the HrpA/HrpB TPS plays a role in the induction of pyroptosis and suggest a pivotal involvement of pyroptosis in invasive meningococcal disease, paving the way for the use of pyroptosis inhibitors in the adjuvant therapy of the disease.

Spread of the meningococci group C isolates of the clonal complex 10217 beyond the African meningitis belt

ObjectivesTo monitor the spread of invasive meningococcal disease due to group C of the clonal complex 10217 isolates beyond the sub-Saharan African meningitis belt. MethodsCases were confirmed by real-time polymerase chain reaction in blood or cerebrospinal fluid samples and further characterized by multi-locus sequence typing that defined sequence type and clonal complexes. Sequencing of penA gene (encoding the penicillin-binding protein 2) was also used to predict susceptibility to β-lactams. ResultsBetween July and December 2023, we identified four cases of invasive meningococcal disease among adults, with two fatal cases in Algeria. Three cases were among subjects who recently arrived in Algeria from sub-Saharan African countries and one case was reported in an autochthonal subject. A case was also detected in France in 2018 in a subject who traveled to Cameroon. All five cases were provoked by group C isolates and belonged to the clonal complex cc10217 with identical PorA (P1.21-15,16) and FetA (F1-7) markers. The penA sequencing revealed a wildtype allele that is correlated to susceptibility to β-lactams. ConclusionsOur results suggest that serogroup C isolates belonging to cc10217 are spreading beyond the meningitis belt. The data underscore the need for enhanced surveillance to inform vaccination strategies.

Follow-up care experience of patients with invasive meningococcal disease and their family caregivers: a qualitative study

BackgroundClinical guidelines recommend systematic follow-up of patients surviving invasive meningococcal disease (IMD) to assess sequelae. However, little is known about survivors and family caregivers’ experiences of the follow-up care. Study sought to explore IMD survivors’ and their family caregivers’ experiences after hospitalization for IMD and to identify unmet needs.MethodsSemi-structured interviews were conducted with patients and family caregivers, identified through hospitals database. Interviews were audiotaped, transcribed and subject to a thematic analysis. NVivo software was used for data management and analysis.ResultsEight IMD survivors and 14 family caregivers were interviewed. Three themes were identified from the data: (1) perception of patient and family caregiver on follow-up after IMD and role of healthcare professionals; (2) access to care and support; (3) relationship with healthcare professionals. Although most were satisfied with follow-up care after IMD, suggestions for improving the healthcare pathway were made relating information on potential sequelae and follow-up care, coordination, and access to psychological support.ConclusionsThis study confirms the need for more structured follow-up care for patients suffering from IMD and their families which is currently limited and focused on physical recovery. Optimal follow-up should aim to provide sufficient information, emotional support and logistical support for patient and family caregivers.Trial registrationEthics Committee of University of Lyon, France (ref: 2022-06-23-002).

Invasive meningococcal disease presenting with tenosynovitis.

Invasive meningococcal disease presenting with tenosynovitis.

Adjuvant-dependent impacts on vaccine-induced humoral responses and protection in preclinical models of nasal and genital colonization by pathogenic Neisseria.

Neisseria gonorrhoeae, which causes the sexually transmitted infection gonorrhea and N. meningitidis, a leading cause of bacterial meningitis and septicemia, are closely related human-restricted pathogens that inhabit distinct primary mucosal niches. While successful vaccines against invasive meningococcal disease have been available for decades, the rapid rise in antibiotic resistance has led to an urgent need to develop an effective gonococcal vaccine. Several surface antigens are shared among these two pathogens, making cross-species protection an exciting prospect. However, the type of vaccine-mediated immune response required to achieve protection against respiratory versus genital infection remains ill defined. In this study, we utilize well established mouse models of female lower genital tract colonization by N. gonorrhoeae and upper respiratory tract colonization by N. meningitidis to examine the performance of transferrin binding protein B (TbpB) vaccines formulated with immunologically distinct vaccine adjuvants. We demonstrate that vaccine-mediated protection is influenced by the choice of adjuvant, with Th1/2-balanced adjuvants performing optimally against N. gonorrhoeae, and both Th1/2-balanced and Th2-skewing adjuvants leading to a significant reduction in N. meningitidis burden. We further establish a lack of correlation between protection status and the humoral response or bactericidal titre. Combined, this work provides supports the feasibility for a single vaccine formulation to achieve pan-neisserial coverage.

Human transferrin and lactoferrin cooperatively support Neisseria meningitidis colonization in the murine nasopharynx.

Neisseria meningitidis is a human-restricted bacteria that is a normal nasopharyngeal resident, yet it can also disseminate, causing invasive meningococcal disease. Meningococci are highly adapted to life in humans, with human-specific virulence factors contributing to bacterial adhesion, nutrient acquisition and immune evasion. While these factors have been explored in isolation, their relative contribution during infection has not been considered due to their absence in small animal models and their expression by different human cell types not readily combined in either in vitro or ex vivo systems. Herein, we show that transgenic expression of the iron-binding glycoproteins human transferrin and lactoferrin can each facilitate N. meningitidis replication in mouse serum but that transferrin was required to support infection-induced sepsis. While these host proteins are insufficient to allow nasopharyngeal colonization alone, mice co-expressing these and human CEACAM1 support robust colonization. In this case, meningococcal colonization elicits an acute elevation in both transferrin and lactoferrin levels within the upper respiratory mucosa, with transferrin levels remaining elevated while lactoferrin returns to basal levels after establishment of infection. Competitive infection of triple transgenic animals with transferrin- and lactoferrin- binding protein mutants selects for bacteria expressing the transferrin receptor, implicating the critical contribution of transferrin-based iron acquisition to support colonization. These transgenic animals have thus allowed us to disentangle the relative contribution of three virulence factors during colonization and invasive disease, and provides a novel in vivo model that can support extended meningococcal colonization, opening a new avenue to explore the meningococcal lifestyle within its primary niche.

Understanding the Sequelae of Invasive Meningococcal Disease in the United States.

Invasive meningococcal disease (IMD) is an uncommon but serious and potentially fatal condition that can result in reduced life expectancy and a broad spectrum of sequelae, many of which may be lifelong and devastating for those who survive the acute disease period. In the United States of America (USA), vaccination is available against the five meningococcal serogroups (A, B, C, W, and Y), but meningococcal vaccination rates among healthy USA adolescents and individuals at high risk because of medical conditions are low, rendering them vulnerable to IMD and its sequelae. Despite the severity of the disease, the clinical impact and rates of IMD sequelae in the USA are poorly understood, as USA-specific data are limited, and the methodology of existing research is heterogenous. This commentary presents clinical experts' perspectives on IMD sequelae based on the available published evidence and direct clinical experience. Among sequelae previously identified in a global systematic literature review, 16 conditions were considered as related to IMD by the present authors. These sequelae include short- and long-term physical, neurological, and emotional consequences that impose a substantial humanistic burden on survivors and their caregivers and result in considerable healthcare and societal costs. This commentary highlights existing knowledge gaps concerning IMD sequelae, including the unclear relationship between IMD and mental health disorders, the contribution of sequelae to the disease burden, prevalence of late-onset sequelae among survivors, and timing of the development of sequelae in different age groups. Addressing these knowledge gaps can inform decisions regarding clinical management in the post-acute period and help quantify the impact of prevention through meningococcal vaccination.

Public health management of invasive meningococcal disease outbreaks: worldwide 1973–2018, a systematic review

BackgroundInfectious disease outbreaks are an ongoing public health concern, requiring extensive resources to prevent and manage. Invasive Meningococcal Disease (IMD) is a severe outcome of infection with Neisseria meningitidis bacteria, which can be carried and transmitted asymptomatically. IMD is not completely vaccine-preventable, presenting an ongoing risk of outbreak development. This review provides a retrospective assessment of public health management of IMD outbreaks.MethodsA systematic search was performed in PubMed and EMBASE. English-language studies reporting on IMD outbreaks and associated public health response were considered eligible. Reporting on key characteristics including outbreak size, duration, location, and public health response were assessed against Strengthening the Reporting of Observational studies in Epidemiology guidelines. A summary of lessons learned and author recommendations for each article were also discussed.Results39 eligible studies were identified, describing 35 outbreaks in seven regions. Responses to outbreaks were mostly reactive, involving whole communities over prioritising those at highest risk of transmission. Recent responses identified a need for more proactive and targeted controls. Reporting was inconsistent, with key characteristics such as outbreak size, duration, or response absent or incompletely described.ConclusionThere is a need for clear, comprehensive reporting on IMD outbreaks and their public health response to inform policy and practice for subsequent outbreaks of IMD and other infectious diseases.

Impact of twelve immunization-preventable infectious diseases on population health using disability-adjusted life years (DALYs) in Spain

BackgroundThe objective of this study is to estimate the burden of selected immunization-preventable infectious diseases in Spain using the Burden of Communicable Diseases in Europe (BCoDE) methodology, as well as focusing on the national immunization programme and potential new inclusions.MethodsThe BCoDE methodology relies on an incidence and pathogen-based approach to calculate disease burden via disability-adjusted life year (DALY) estimates. It considers short and long-term sequelae associated to an infection via outcome trees. The BCoDE toolkit was used to populate those trees with Spanish-specific incidence estimates, and de novo outcome trees were developed for four infections (herpes zoster, rotavirus, respiratory syncytial virus [RSV], and varicella) not covered by the toolkit. Age/sex specific incidences were estimated based on data from the Spanish Network of Epidemiological Surveillance; hospitalisation and mortality rates were collected from the Minimum Basic Data Set. A literature review was performed to design the de novo models and obtain the rest of the parameters. The methodology, assumptions, data inputs and results were validated by a group of experts in epidemiology and disease modelling, immunization and public health policy.ResultsThe total burden of disease amounted to 163.54 annual DALYs/100,000 population. Among the selected twelve diseases, respiratory infections represented around 90% of the total burden. Influenza exhibited the highest burden, with 110.00 DALYs/100,000 population, followed by invasive pneumococcal disease and RSV, with 25.20 and 10.57 DALYs/100,000 population, respectively. Herpes zoster, invasive meningococcal disease, invasive Haemophilus influenza infection and hepatitis B virus infection ranked lower with fewer than 10 DALYs/100,000 population each, while the rest of the infections had a limited burden (< 1 DALY/100,000 population). A higher burden of disease was observed in the elderly (≥ 60 years) and children < 5 years, with influenza being the main cause. In infants < 1 year, RSV represented the greatest burden.ConclusionsAligned with the BCoDE study, the results of this analysis show a persisting high burden of immunization-preventable respiratory infections in Spain and, for the first time, highlight a high number of DALYs due to RSV. These estimates provide a basis to guide prevention strategies and make public health decisions to prioritise interventions and allocate healthcare resources in Spain.

Genomic oropharyngeal Neisseria surveillance detects MALDI-TOF MS species misidentifications and reveals a novel Neisseria cinerea clade.

Introduction. Commensal Neisseria spp. are highly prevalent in the oropharynx as part of the healthy microbiome. N. meningitidis can colonise the oropharynx too from where it can cause invasive meningococcal disease. To identify N. meningitidis, clinical microbiology laboratories often rely on Matrix Assisted Laser Desorption/Ionisation Time of Flight Mass Spectrometry (MALDI-TOF MS).Hypothesis/Gap statement. N. meningitidis may be misidentified by MALDI-TOF MS.Aim. To conduct genomic surveillance of oropharyngeal Neisseria spp. in order to: (i) verify MALDI-TOF MS species identification, and (ii) characterize commensal Neisseria spp. genomes.Methodology. We analysed whole genome sequence (WGS) data from 119 Neisseria spp. isolates from a surveillance programme for oropharyngeal Neisseria spp. in Belgium. Different species identification methods were compared: (i) MALDI-TOF MS, (ii) Ribosomal Multilocus Sequence Typing (rMLST) and (iii) rplF gene species identification. WGS data were used to further characterize Neisseria species found with supplementary analyses of Neisseria cinerea genomes.Results. Based on genomic species identification, isolates from the oropharyngeal Neisseria surveilence study were composed of the following species: N. meningitidis (n=23), N. subflava (n=61), N. mucosa (n=15), N. oralis (n=8), N. cinerea (n=5), N. elongata (n=3), N. lactamica (n=2), N. bacilliformis (n=1) and N. polysaccharea (n=1). Of these 119 isolates, four isolates identified as N. meningitidis (n=3) and N. subflava (n=1) by MALDI-TOF MS, were determined to be N. polysaccharea (n=1), N. cinerea (n=2) and N. mucosa (n=1) by rMLST. Phylogenetic analyses revealed that N. cinerea isolates from the general population (n=3, cluster one) were distinct from those obtained from men who have sex with men (MSM, n=2, cluster two). The latter contained genomes misidentified as N. meningitidis using MALDI-TOF MS. These two N. cinerea clusters persisted after the inclusion of published N. cinerea WGS (n=42). Both N. cinerea clusters were further defined through pangenome and Average Nucleotide Identity (ANI) analyses.Conclusion. This study provides insights into the importance of genomic genus-wide Neisseria surveillance studies to improve the characterization and identification of the Neisseria genus.

Quantifying Stated Preferences for Meningococcal Vaccines Among Adolescents/Young Adults and Parents of Adolescents in the United States: A Discrete Choice Experiment.

Invasive meningococcal disease (IMD) is a severe and life-threatening disease. In the United States (US), vaccine coverage with MenACWY and MenB meningococcal vaccines is suboptimal among adolescents/young adults aged 16-23years. A combined meningococcal vaccine (MenABCWY) could increase convenience (e.g., fewer injections) and improve coverage. The objective was to quantify preferences for hypothetical meningococcal vaccine profiles among adolescents/young adults and parents. An online discrete choice experiment was conducted among 16- to 23-year-olds, and parents of 16- to 18-year-olds. Attributes (3×4) and levels (1×2) were based on the literature and focus groups. Participants made ten pair-wise forced trade-off choices, systematically varied using a D-optimal design. Random parameter logit quantified the relative importance of vaccination attributes and estimated the trade-offs. Differences in preferences by subgroups were assessed. Totals of 300 adolescents and young adults (median age 20years) and 300 parents (median age 46years) completed the survey. Overall, 89.6% of 16- to 23-year-olds and 69.1% of parents preferred a simplified hypothetical meningococcal vaccination profile, e.g., with fewer injections (3 vs. 4) and fewer healthcare provider (HCP) visits (2-3 vs. 4). Having HCP advice and clear Centers for Disease Control and Prevention recommendations impacted vaccination choice, with both groups reporting high trust in HCP information (83.3% among 16- to 23-year-olds; 98.7% among parents). Barriers to vaccination included lack of HCP advice or awareness of meningococcal vaccines, and income level and out-of-pocket costs for parents. Adolescents/young adults and parents demonstrated a significant preference for a meningococcal vaccine that is more convenient (such as combined MenABCWY). Parents' vaccination preferences differed by income level and out-of-pocket costs, suggesting financial barriers to vaccination may exist which could result in IMD prevention inequalities. Findings from this study provide important information to support patient-facing informed policy discussions. A simplified vaccination schedule and strong recommendation could help improve vaccine uptake, schedule compliance, disease prevention, and reduce inequalities in IMD risk and prevention. A graphical abstract is available with this article.