Serogroup-specific meningococcal carriage by age group: a systematic review and meta-analysis

Cost-effectiveness analysis of vaccination strategies against meningococcal disease for children under nine years of age in China

Meningococcal vaccination strategies in China are intricate, including multiple vaccines targeting different serogroups. The current National Immunization Program (NIP) includes two polysaccharide vaccines for serogroups A and C (MPV-A and MPV-AC), covering limited serogroups and requiring adaptation. This study aims to evaluate the cost-effectiveness of replacing the current strategy with alternative strategies utilizing non-NIP vaccines to inform policy decisions. From a societal perspective, a decision tree-Markov model was constructed to simulate the economic and health consequences of meningococcal disease in a 2019 birth cohort with four vaccination strategies. Epidemiology, vaccine efficacy, cost, and other parameters were derived from previous studies. We conducted sensitivity analyses to assess the robustness of the findings and explored prices for non-NIP vaccines that enable cost-effective strategies. Compared to the current strategy, alternative strategies using quadrivalent polysaccharide vaccine (MPV-4), bivalent conjugate vaccine (MCV-AC), and quadrivalent conjugate vaccine (MCV-4) could avoid 91, 286, and 455 more meningococcal cases. The ICERs were estimated at approximately $250 thousand/QALY, $450 thousand/QALY, and $1.5 million/QALY, all exceeding the threshold of three times GDP per capita. The alternative strategies were not cost-effective. However, if vaccine prices were reduced to $3.9 for MPV-4, $9.9 for MCV-AC, and $12 for MCV-4, the corresponding strategy would be cost-effective. The current meningococcal vaccination strategy in China could effectively prevent the disease at a low cost, but with limited serogroup coverage. Strategies using MPV-4, MCV-AC, or MCV-4 could increase health benefits at a substantial cost, and might become cost-effective if vaccine prices decrease.

Economic evaluation on meningococcal vaccination strategies among children under nine years of age in Zhejiang province, China

Meningococcal vaccination in Chinese national immunization program (NIP) includes polysaccharide vaccine against Neisseria meningitidis serogroup A (MPV-A) and polysaccharide vaccine against Neisseria meningitidis serogroup A and C(MPV-AC). This study aimed to assess the cost-effectiveness of an alternative strategy using polysaccharide conjugate vaccine against Neisseria meningitidis serogroup A,C,W,Y(MCV-ACWY) and polysaccharide vaccine against Neisseria meningitidis serogroup A,C,W,Y(MPV-ACWY). From a societal perspective, we constructed a decision tree-Markov model to simulate the economic and health consequences of meningococcal disease in a 2023 birth cohort with the current meningococcal vaccination strategy and the alternative. Parameters of epidemiology, vaccine efficacy, cost, and utility were extracted from database and previous literatures. The sensitivity analysis was implemented to evaluate the robustness of the model. Compared to the current practice, the alternative strategy could avoid 513 meningococcal disease cases, 53 sequelae and 47 deaths. The ICER was estimated at $16899.81 /QALY, under the threshold of one time of the GDP per capita of Zhejiang province in 2023. The incidence of meningococcemia, the incidence of meningococcal meningitis, the case fatality of meningococcemia, the vaccine efficacy of MCV-ACWY and the price of MCV-ACWY would influence the cost-effectiveness of the meningococcal vaccination strategies. At the threshold, the probability of cost-effectiveness was 14.76% for the current strategy and 55.98% for the alternative strategy, respectively. The current meningococcal vaccination strategy had effectively prevented meningococcal disease at a low cost, but with limited serogroup coverage. Strategy using MCV-ACWY and MPV-ACWY could increase health benefits at a substantial cost at a cost-effective manner.

Diverse proinflammatory response in pharyngeal epithelial cells upon interaction with Neisseria meningitidis carriage and invasive isolates

BACKGROUND

Invasive meningococcal disease (IMD), including sepsis and meningitis, can develop when Neisseria meningitidis bacteria breach the barrier and gain access to the circulation. While IMD is a rare outcome of bacterial exposure, colonization of the oropharynx is present in approximately 10% of the human population. This asymptomatic carriage can be long or short term, and it is unknown which determining factors regulate bacterial colonization. Despite descriptions of many bacterial virulence factors and recent advances in detailed genetic identification and characterization of bacteria, the factors mediating invasion and disease vs. asymptomatic carriage following bacterial colonization remain unknown. The pharyngeal epithelia play a role in the innate immune defense against pathogens, and the aim of this study was to investigate the proinflammatory response of pharyngeal epithelial cells following meningococcal exposure to describe the potential inflammatory mediation performed during the initial host‒pathogen interaction. Clinically relevant isolates of serogroups B, C, W and Y, derived from patients with meningococcal disease as well as asymptomatic carriers, were included in the study.

RESULTS

The most potent cellular response with proinflammatory secretion of TNF, IL-6, CXCL8, CCL2, IL-1β and IL-18 was found in response to invasive serogroup B isolates. This potent response pattern was also mirrored by increased bacterial adhesion to cells as well as induced cell death. It was, however, only with serogroup B isolates where the most potent cellular response was toward the IMD isolates. In contrast, the most potent cellular response using serogroup Y isolates was directed toward the carriage isolates rather than the IMD isolates. In addition, by comparing isolates from outbreaks in Sweden (epidemiologically linked and highly genetically similar), we found the most potent proinflammatory response in cells exposed to carriage isolates rather than the IMD isolates.

CONCLUSION

Although certain expected correlations between host‒pathogen interactions and cellular proinflammatory responses were found using IMD serogroup B isolates, our data indicate that carriage isolates invoke stronger proinflammatory activation of the epithelial lining than IMD isolates.

Geographical distribution of invasive meningococcal disease and carriage: A spatial analysis

Little information exists concerning the spatial relationship between invasive meningococcal disease (IMD) cases and Neisseria meningitidis (N. meningitidis) carriage. The aim of this study was to examine whether there is a relationship between IMD and asymptomatic oropharyngeal carriage of meningococci by spatial analysis to identify the distribution and patterns of cases and carriage in South Australia (SA). Carriage data geocoded to participants' residential addresses and meningococcal case notifications using Postal Area (POA) centroids were used to analyse spatial distribution by disease- and non-disease-associated genogroups, as well as overall from 2017 to 2020. The majority of IMD cases were genogroup B with the overall highest incidence of cases reported in infants, young children, and adolescents. We found no clear spatial association between N. meningitidis carriage and IMD cases. However, analyses using carriage and case genogroups showed differences in the spatial distribution between metropolitan and regional areas. Regional areas had a higher rate of IMD cases and carriage prevalence. While no clear relationship between cases and carriage was evident in the spatial analysis, the higher rates of both carriage and disease in regional areas highlight the need to maintain high vaccine coverage outside of the well-resourced metropolitan area.

The important lessons lurking in the history of meningococcal epidemiology

INTRODUCTION

The epidemiology of invasive meningococcal disease (IMD), a rare but potentially fatal illness, is typically described as unpredictable and subject to sporadic outbreaks.

AREAS COVERED

Meningococcal epidemiology and vaccine use during the last ~ 200 years are examined within the context of meningococcal characterization and classification to guide future IMD prevention efforts.

EXPERT OPINION

Historical and contemporary data highlight the dynamic nature of meningococcal epidemiology, with continued emergence of hyperinvasive clones and affected regions. Recent shifts include global increases in serogroup W disease, meningococcal antimicrobial resistance (AMR), and meningococcal urethritis; additionally, unvaccinated populations have experienced disease resurgences following lifting of COVID-19 restrictions. Despite these changes, a close analysis of meningococcal epidemiology indicates consistent dominance of serogroups A, B, C, W, and Y and elevated IMD rates among infants and young children, adolescents/young adults, and older adults. Demonstrably effective vaccines against all 5 major disease-causing serogroups are available, and their prophylactic use represents a powerful weapon against IMD, including AMR. The World Health Organization's goal of defeating meningitis by the year 2030 demands broad protection against IMD, which in turn indicates an urgent need to expand meningococcal vaccination programs across major disease-causing serogroups and age-related risk groups.

Meningococcal carriage in children and young adults: a cross-sectional and longitudinal study, Iceland, 2019 to 2021

BackgroundNeisseria meningitidis is a commensal bacterium which can cause invasive disease. Colonisation studies are important to guide vaccination strategies.AimThe study's aim was to determine the prevalence of meningococcal colonisation, duration of carriage and distribution of genogroups in Iceland.MethodsWe collected samples from 1 to 6-year-old children, 15-16-year-old adolescents and 18-20-year-old young adults. Carriers were sampled at regular intervals until the first negative swab. Conventional culture methods and qPCR were applied to detect meningococci and determine the genogroup. Whole genome sequencing was done on groupable meningococci.ResultsNo meningococci were detected among 460 children, while one of 197 (0.5%) adolescents and 34 of 525 young adults (6.5 %) carried meningococci. Non-groupable meningococci were most common (62/77 isolates from 26/35 carriers), followed by genogroup B (MenB) (12/77 isolates from 6/35 carriers). Genogroup Y was detected in two individuals and genogroup W in one. None carried genogroup C (MenC). The longest duration of carriage was at least 21 months. Serial samples from persistent carriers were closely related in WGS.ConclusionsCarriage of pathogenic meningococci is rare in young Icelanders. Non-groupable meningococci were the most common colonising meningococci in Iceland, followed by MenB. No MenC were found. Whole genome sequencing suggests prolonged carriage of the same strains in persistent carriers.

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

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

Validation and use of a serum bactericidal antibody assay for Neisseria meningitidis serogroup X in a seroprevalence study in Niger, West Africa

Invasive meningococcal disease (IMD) affects approximately 1.2 million people worldwide annually. Prevention of IMD is mostly provided through vaccination; however, no licensed vaccine is currently available to protect against meningococcal serogroup X associated infection. Limited data are available on the natural immunity to Neisseria meningitidis serogroup X within the African sub-Saharan meningitis belt. The objective of the study was to provide an overview of natural immunity to serogroup X within a community in the African meningitis belt prior to the introduction of a pentavalent conjugate vaccine (NmCV-5). Prior to its introduction, a validated assay to assess vaccine efficacy was also required. This study therefore incorporated two objectives: a seroprevalence study to assess natural immunity in serum samples (n = 377) collected from Niger, West Africa in 2012, and the validation of a serogroup X serum bactericidal antibody (SBA) assay. Seroprevalence data obtained found that natural immunity to N. meningitidis serogroup X were present in 52.3% of study participants. The highest putative protective titres (≥8) to serogroup X were seen in age group 5-14 years-old (73.9%) and lowest in ages < 1 year old (0%). The SBA assay was successfully validated for selectivity/specificity, precision/reproducibility, linearity, and stability. This study demonstrated the suitability of the serogroup X SBA assay in clinical trials for future meningococcal conjugate vaccines containing serogroup X polysaccharides.

Demographic Features of Invasive Meningococcal Disease in Taiwan, 1993 to 2020, and Genetic Characteristics of Neisseria meningitidis Isolates, 2003 to 2020

We present the demographic features of invasive meningococcal disease (IMD) in Taiwan between 1993 and 2020 and the genetic characteristics of Neisseria meningitidis isolates recovered from 2003 to 2020. IMD was rare in Taiwan between 1993 and 2020, with an annual incidence ranging from 0.009 to 0.204 per 100,000 people. The case fatality rate (CFR) declined from 18.1% for patients in 1993 to 2002 to 9.8% in 2003 to 2020. Infants less than 12 months were most susceptible to the disease. N. meningitidis serogroup B (NmB) was most predominant, responsible for 81.2% (134/165) of the IMD cases in 2003 to 2020. The majority of the isolates recovered from 2003 to 2020 belonged to 4 worldwide-spread hyperinvasive clonal complexes (cc), cc4821 (30.3%), cc32 (19.4%), cc41/44 (12.7%), cc23 (7.3%), and also a newly assigned clonal complex, cc3439 (10.3%). Core genome multilocus sequence typing (cgMLST) profile comparisons revealed that the cc4821 isolates with a T-to-I substitution at position 91 in gyrA were closely related to those originating from China. Of the 165 isolates, 20.0% and 53.3% were predicted to be covered by the Bexsero and Trumenba vaccines, respectively, whereas, 77.0% and 46.7% remained indeterminate. In conclusion, N. meningitidis isolates recovered in Taiwan between 2003 and 2020 were mostly highly diverse. Most IMD cases appeared sporadically and were caused by localized strains, although some patients were infected by recently introduced strains. cgMLST is a powerful tool for the rapid comparison of genetic relatedness among a large number of isolates. cgMLST profiling, based on 1,241 core genes, and strain tracking can be performed on the website of cgMLST@Taiwan (http://rdvd.cdc.gov.tw/cgMLST/). IMPORTANCE N. meningitidis can cause life-threatening invasive meningococcal disease (IMD), including meningitis and sepsis, resulting in a high CFR and long-term sequelae in survivors. Here, we report the demographic features of IMD in Taiwan over a 28-year period (1993 to 2020) and the genetic characteristics of N. meningitidis isolates recovered from patients with IMD over an 18-year period (2003 to 2020). We conducted a whole-genome sequence analysis to characterize the genetic features of the isolates and developed a cgMLST scheme for epidemiological investigation and strain tracking. The findings can be beneficial in understanding the epidemiology of IMD in Taiwan, the genetic characteristics of the bacterial strains, and the distribution of vaccine antigens for vaccine development and implementation.

Sequelae at Hospital Discharge in 61 Children With Invasive Meningococcal Disease, Chile, 2009-2019

BACKGROUND

Invasive meningococcal disease (IMD) is an unpredictable and severe infection caused by Neisseria meningitidis . Its case fatality rate could vary from 9.7% to 26% and up to 36% of survivors may experience long-term sequelae, representing a challenge for public health.

AIMED

To describe the sequelae at hospital discharge caused by IMD in children between years 2009-2019.

METHODS

Cross-sectional study performed in 2 pediatric hospitals. Patients with microbiologically confirmed diagnosis of IMD from 2009 to 2019 were included. Bivariate and logistic regression analysis were performed.

RESULTS

The records of 61 patients were reviewed and included. Sixty-seven percent were male, median age 9 months (interquartile range 4-27), 72% were admitted to intensive care unit. Thirty-seven (60.5%) had at least 1 sequela (75% and 37% in patients with or without meningitis, respectively). The most frequents sequelae were neurological 72%, hearing loss 32%, and osteoarticular 24%. Significant differences were found comparing patients with and without sequelae: drowsiness 67.6% versus 41.7% ( P = 0.04), irritability 67.6% versus 25% ( P = 0.01), meningeal signs 62.2% versus 29.2% ( P = 0.01). In logistic regression analysis, postdischarge follow-up had OR 21.25 (95% confidence intervals [CI]: 4.93-91.44), irritability had OR 8.53 (95% CI: 1.64-44.12), meningeal signs had OR 8.21 (95% CI: 0.71-94.05), invasive mechanical ventilation had OR 8.23 (95% CI: 0.78-85.95), meningitis plus meningococcemia OR 1.70 (95% CI: 0.18-15.67) to have sequelae, while children with meningococcemia and vomiting had a OR 0.04 (95% CI: 0.00-0.36) and OR 0.27 (95% CI: 0.03-2.14), respectively. N. meningitidis serogroup W (MenW) was isolated in 54.1% (33/61), and N. meningitidis serogroup B (MenB) in 31.1% (19/61) of cases. A significant difference was found in osteoarticular sequelae ( P = 0.05) between MenB and MenW. There was a decrease in cases after the meningococcal conjugate vaccine against serogroups A, C, W and Y was implemented (2015-2019).

CONCLUSIONS

IMD remains as a public health concern. A high rate of sequelae was found in pediatric patients in our series, even in the clinical manifestations other than meningitis. Neurological sequelae were the most prevalent. Multidisciplinary follow-up protocols to reduce long-term impact must be urgently established to assess all children with IMD.

Carriage prevalence of Neisseria meningitidis in China, 2005-2022: a systematic review and meta-analysis

INTRODUCTION

Neisseria meningitidis (Nm) is a major cause of meningitis and septicemia. Most people are infected with latent infections or are carriers. We aimed to estimate the carriage prevalence of Nm in China.

METHODS

We did a systematic review of published work to assess the prevalence of meningococcal carriage in China. The quality assessment was conducted by the risk of bias tool according to Damian Hoy's study. We estimated pooled proportions of carriage and its 95% confidence interval (95% CI) using fixed effect model for studies with low heterogeneity and random effect model for studies with moderate or high heterogeneity. Subgroup analyses were also conducted by region and age group.

RESULTS

In total, 115 studies were included. The quality evaluation grades of all included documents were medium or high grade. The weighted proportion of carriage was 2.86% (95% CI: 2.25-3.47%, I2: 97.7%, p = 0). The carriage prevalence of Nm varied between provinces, ranged from 0.00% (95% CI: 0.00-0.66%) to 15.50% (95% CI: 14.01-16.99%). Persons aged 15 years and older had the highest carriage 4.38% (95% CI: 3.15-5.62%, I2: 95.4%, p < 0.0001), and children under 6 years of age had the lowest carriage 1.01% (95% CI: 0.59-1.43%, I2: 74.4%, p < 0.0001). In positive carriers, serogroup B (41.62%, 95% CI: 35.25-48.00%, I2: 98.6%, p = 0) took up the highest proportion, and serogroup X (0.02%, 95% CI: 0.00-0.09%, I2: 0.00%, p = 1) accounted for the lowest proportion.

CONCLUSION

The meningococcal carriage in China was estimated low and varied by region and age group. Understanding the epidemiology and transmission dynamics of meningococcal infection in insidious spreaders is essential for optimizing the meningococcal immunization strategies of the country.

Induction of Susceptibility to Disseminated Infection with IgA1 Protease-Producing Encapsulated Pathogens Streptococcus pneumoniae, Haemophilus influenzae Type b, and Neisseria meningitidis

Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae are the principal causes of bacterial meningitis. It is unexplained why only occasional individuals develop invasive infection, while the vast majority remain healthy and develop immunity when encountering these pathogens. A capsular polysaccharide and an IgA1 protease are common to these pathogens. We tested the hypothesis that patients are primed to susceptibility to invasive infection by other bacteria that express the same capsular polysaccharide but no IgA1 protease. Thereby, the subsequently colonizing pathogen may protect its surface with IgA1 protease-generated Fab fragments of IgA1 devoid of Fc-mediated effector functions. Military recruits who remained healthy when acquiring meningococci showed a significant response of inhibitory antibodies against the IgA1 protease of the colonizing clone concurrent with serum antibodies against its capsular polysaccharide. At hospitalization, 70.8% of meningitis patients carried fecal bacteria cross-reactive with the capsule of the actual pathogen, in contrast to 6% of controls (P < 0.0001). These were Escherichia coli K100, K1, and K92 in patients with infection caused by H. influenzae type b and N. meningitidis groups B and C, respectively. This concurred with a significant IgA1 response to the capsule but not to the IgA1 protease of the pathogen. The demonstrated multitude of relationships between capsular types and distinct IgA1 proteases in pneumococci suggests an alternative route of immunological priming associated with recombining bacteria. The findings support the model and offer an explanation for the rare occurrence of invasive diseases in spite of the comprehensive occurrence of the pathogens.

Meningococcal Carriage in 'Men Having Sex With Men' With Pharyngeal Gonorrhoea

We assessed the characteristics of Neisseria meningitidis pharyngeal carriage in a cohort of ‘men having sex with men’, including patients with pharyngeal Neisseria gonorrhoeae infection. In the period 2017-2019, among all the oropharyngeal samples tested for gonorrhoea from MSM attending a STI Clinic in Bologna (Italy), we randomly selected 244 N. gonorrhoeae-positive samples and 403 negatives (n=647). Pharyngeal specimens were tested for N. meningitidis presence, by the detection of sodC gene. N. meningitidis-positive samples were further grouped by PCR tests for the major invasive genogroups (i.e., A, B, C, W, and Y). A molecular assay, targeting capsule transporter gene, was used to determine meningococcal capsular status. Overall, 75.8% (491/647) of samples tested positive for sodC gene, indicating a pharyngeal meningococcal carriage. Meningococcal colonisation was significantly more frequent in younger subjects (P=0.009), with no association with HIV infection. Non-groupable meningococci represented most of pharyngeal carriages (about 71%). The commonest N. meningitidis serogroup was B (23.6%), followed by C (2.1%), Y (1.8%) and W (1.1%). Meningococci were often characterized by the genetic potential of capsule production. Interestingly, a negative association between N. meningitidis and N. gonorrhoeae was found: pharyngeal gonorrhoea was significantly more present in patients without meningococcal carriage (P=0.03). Although preliminary, our data added knowledge on the epidemiology of meningococcal carriage in MSM communities at high risk of gonococcal infections, gaining new insights into the interactions/dynamics between N. meningitidis and N. gonorrhoeae.

Antimicrobial susceptibility of commensal Neisseria in a general population and men who have sex with men in Belgium

Non-pathogenic Neisseria are a reservoir of antimicrobial resistance genes for pathogenic Neisseria meningitidis and Neisseria gonorrhoeae. Men who have sex with men (MSM) are at risk of co-colonization with resistant non-pathogenic and pathogenic Neisseria. We assessed if the antimicrobial susceptibility of non-pathogenic Neisseria among MSM differs from a general population and if antimicrobial exposure impacts susceptibility. We recruited 96 participants at our center in Belgium: 32 employees, 32 MSM who did not use antibiotics in the previous 6 months, and 32 MSM who did. Oropharyngeal Neisseria were cultured and identified with MALDI-TOF–MS. Minimum inhibitory concentrations for azithromycin, ceftriaxone and ciprofloxacin were determined using E-tests^® and compared between groups with non-parametric tests. Non-pathogenic Neisseria from employees as well as MSM were remarkably resistant. Those from MSM were significantly less susceptible than employees to azithromycin and ciprofloxacin (p < 0.0001, p < 0.001), but not ceftriaxone (p = 0.3). Susceptibility did not differ significantly according to recent antimicrobial exposure in MSM. Surveilling antimicrobial susceptibility of non-pathogenic Neisseria may be a sensitive way to assess impact of antimicrobial exposure in a population. The high levels of antimicrobial resistance in this survey indicate that novel resistance determinants may be readily available for future transfer from non-pathogenic to pathogenic Neisseria.

Detection of Neisseria meningitidis in saliva and oropharyngeal samples from college students

Carriage of Neisseria meningitidis is an accepted endpoint in monitoring meningococcal vaccines effects. We have assessed N. meningitidis and vaccine-type genogroup carriage prevalence in college students at the time of MenACWY vaccine introduction in the Netherlands, and evaluated the feasibility of saliva sampling for the surveillance of carriage. For this, paired saliva and oropharyngeal samples collected from 299 students were cultured for meningococcus. The DNA extracted from all bacterial growth was subjected to qPCRs quantifying meningococcal and genogroup-specific genes presence. Samples negative by culture yet positive for qPCR were cultured again for meningococcus. Altogether 74 (25%) of students were identified as meningococcal carrier by any method. Sixty-one students (20%) were identified as carriers with qPCR. The difference between number of qPCR-positive oropharyngeal (n = 59) and saliva (n = 52) samples was not significant (McNemar’s test, p = 0.07). Meningococci were cultured from 72 students (24%), with a significantly higher (p < 0.001) number of oropharyngeal (n = 70) compared with saliva (n = 54) samples. The prevalence of genogroups A, B, C, W, and Y was none, 9%, 1%, 1% and 6%, respectively, and 8% of students carried MenACWY vaccine-type genogroup meningococci. Saliva is easy to collect and when combined with qPCR detection can be considered for meningococcal carriage studies.

4CMenB vaccine and its role in preventing transmission and inducing herd immunity

INTRODUCTION

: Vaccination is the most effective method of protecting people from invasive meningococcal disease (IMD). Of all the capsular groups, B is the most common cause of invasive meningococcal disease in many parts of the world. Despite this, adolescent meningococcal B vaccine programs have not been implemented globally, partly due to the lack of evidence for herd immunity afforded by meningococcal B vaccines.

AREAS COVERED

This review aims to synthesise the available evidence on recombinant 4CMenB vaccines' ability to reduce pharyngeal carriage and therefore provide indirect (herd) immunity against IMD.

EXPERT OPINION

There is some evidence that the 4CMenB vaccine may induce cross-protection against non-B carriage of meningococci. However, the overall body of evidence does not support a clinically significant reduction in carriage of disease-associated or group B meningococci following 4CMenB vaccination. No additional cost-benefit from herd immunity effects should be included when modelling the cost-effectiveness of 4CMenB vaccine programs against group B IMD. 4CMenB immunisation programs should focus on direct (individual) protection for groups at greatest risk of meningococcal disease.

Future meningococcal B and combination vaccines being developed should consider the impact of the vaccine on carriage as part of their clinical evaluation.

Nasopharyngeal Meningococcal Carriage among Children and Adolescents in Turkey in 2018: An Unexpected High Serogroup X Carriage

Meningococcal carriage studies and transmission modeling can predict IMD epidemiology and used to define invasive meningococcal disease (IMD) control strategies. In this multicenter study, we aimed to evaluate the prevalence of nasopharyngeal Neisseria meningitidis (Nm) carriage, serogroup distribution, and related risk factors in Turkey. Nasopharyngeal samples were collected from a total of 1267 children and adolescents and were tested with rt-PCR. Nm carriage was detected in 96 participants (7.5%, 95% CI 6.1–9.0), with the peak age at 13 years (12.5%). Regarding age groups, Nm carriage rate was 7% in the 0–5 age group, was 6.9%in the 6–10 age group, was 7.9% in the 11–14 age group, and was 9.3% in the 15–18 age group. There was no statistically significant difference between the groups (p > 0.05). The serogroup distribution was as follows: 25% MenX, 9.4% MenA, 9.4% MenB, 2.1% MenC, 3.1% MenW, 2.1% for MenY, and 48.9% for non-groupable. The Nm carriage rate was higher in children with previous upper respiratory tract infections and with a high number of household members, whereas it was lower in children with antibiotic use in the last month (p < 0.05 for all). In this study, MenX is the predominant carriage strain. The geographical distribution of Nm strains varies, but serogroup distribution in the same country might change in a matter of years. Adequate surveillance and/or a proper carriage study is paramount for accurate/dynamic serogroup distribution and the impact of the proposed vaccination.

Recent increased incidence of invasive serogroup W meningococcal disease: A retrospective observational study

OBJECTIVES

Neisseria meningitidis serogroup W incidence has increased. Mortality associated with serogroup W has been higher than for other serogroups. Here we report epidemiological characteristics and risks of poor outcomes associated with invasive meningococcal disease in Denmark since 1980.

METHODS

All cases of invasive meningococcal disease reported from 1980-2018 were analyzed. Incidence rates by age, sex, manifestation, and serogroup were calculated. Poisson regression was used to analyze the rise in serogroup W, and multivariate logistic analysis was used to analyze risk factors for mortality.

RESULTS

A total of 5825 cases were analyzed. Risk of serogroup W infection increased after 2015 compared with all previous periods. Younger (<20 years) and older age (≥60 years) was associated with an increased risk of serogroup W infection compared with being aged 20-39. Crude case fatality was 12.0%, 11.9%, 9.2%, and 7.9% for serogroups W, Y, C, and B, respectively. After adjustment for age, sex, and manifestation, 30-day mortality was comparable for serogroups. Older age and manifestation with sepsis independently predicted risk of death.

CONCLUSIONS

Invasive meningococcal disease caused by serogroup W has increased, but serogroup per se was not associated with an increased risk of 30-day mortality.

The Burden of Invasive Vaccine-Preventable Diseases in Adults in the Middle East and North Africa (MENA) Region

Implementing vaccination programmes at the national level is key to managing vaccine-preventable diseases (VPDs) in the overall population. Although paediatric immunization programmes have significantly reduced the burden of VPD, disease burden in adults still poses a substantial challenge, particularly in low- and middle-income countries such as those within the Middle East and North Africa (MENA) region. Invasive bacterial diseases (IBDs) are an important public health concern within this region, although vaccines are available to prevent the three most common causative organisms associated with IBD: Neisseria meningitidis (NM), Streptococcus pneumoniae (SP), and Haemophilus influenzae (HI). For this review, three separate PubMed searches were used to identify English-language publications describing the epidemiology of NM, SP, and HI in adults within the MENA region. Of the 161 total publications retrieved among all 3 literature searches, 39 were included in this review (NM: 8 publications; SP: 27 publications; HI: 4 publications). Publications describing epidemiology in paediatric or overall populations were excluded. Overall, these studies generally observed a high burden of IBD among adults in this region. Although NM, SP, and HI are communicable diseases in several countries, the surveillance systems in the MENA region are largely inadequate, resulting in poor responses to outbreaks and hindering improvement in outcomes of communicable diseases. Improving IBD surveillance would provide necessary estimates of disease burden, resulting in better vaccination strategies and improved outcomes. In conclusion, the present review provides a summary of the available information on the epidemiology of vaccine-preventable IBD in adults within the MENA region and highlights the need for increased disease surveillance and preventive strategies in these countries.

Prevalence of Therapeutic use of Opioids in Chronic non-Cancer Pain Patients and Associated Factors: A Systematic Review and Meta-Analysis

Objectives: To determine the prevalence and factors associated with the use of opioids among patients with chronic non-cancer pain (CNCP).

Methods: A systematic review and meta-analysis. Comprehensive literature searches in Medline-PubMed, Embase and SCOPUS databases. Original studies published between 2009 and 2019 with a cross-sectional design were included. The quality of the studies was assessed with Critical Appraisal Checklist for Studies Reporting Prevalence Data from the Joanna Briggs Institute. Protocol registered in the International Prospective Register of Systematic Reviews with reference number: CRD42019137990.

Results: Out of the 1,310 potential studies found, 25 studies fulfilled the inclusion criteria. Most of the studies were of high quality. High levels of heterogeneity were found in the studies included. In the general population, the prevalence of long-term opioid use was 2.3% (95% CI: 1.5–3.6%), the prevalence of short-term opioid use was 8.1% (95% CI: 5.6–11.6%), and among people with chronic low back pain it was 5.8% (95% CI: 0.5–45.5%). The prevalence of opioid use among patients from the health records or medical surveys was 41% (95% CI: 23.3–61.3%). Finally, in patients with musculoskeletal pain, the prevalence was 20.5% (95% CI: 12.9–30.9%) and in patients with fibromyalgia, 24.5% (95% CI: 22.9–26.2%). A higher prevalence of opioid use was observed among men, younger people, patients receiving prescriptions of different types of drugs, smokers and patients without insurance or with noncommercial insurance. In addition, non-white and Asian patients were less likely to receive opioids than non-Hispanic white patients.

Conclusions: The prevalence of opioid use among patients with CNCP was higher in subjects with short or occasional use compared to those with long-term use. Men, younger people, more chronic pain conditions, and patients without insurance or with noncommercial insurance were most related to opioid use. However, non-white and Asian patients, and those treated by a physician trained in complementary medicine were less likely to use opioids.

Why the Anti-Meningococcal B Vaccination during Adolescence Should Be Implemented in Italy: An Overview of Available Evidence

Although meningococcal disease has a low incidence in Italy, it is a public health concern owing to its high lethality rate and high frequency of transitory and/or permanent sequelae among survivors. The highest incidence rates are recorded in infants, children and adolescents, and most of the cases are due to Neisseria meningitidis B. In Italy, anti-meningococcal B (anti-MenB) vaccination is free for infants but, despite the considerable disease burden in adolescents, no national recommendation to vaccinate in this age-group is currently available. The aim of this study was to assess the main available scientific evidence to support the Italian health authorities in implementing a program of free anti-MenB vaccination for adolescents. We conducted an overview of the scientific literature on epidemiology, disease burden, immunogenicity and safety of available vaccines, and economic evaluations of vaccination strategies. Each case of invasive meningococcal disease generates a considerable health burden (lethality rate: 9%; up to 60% of patients experience at least one sequela) in terms of impaired quality of life for survivors and high direct and indirect costs (the mean overall cost of acute phase for a single case amounts to about EUR 13,952; the costs for post-acute and the long-term phases may vary widely depending of the type of sequela, reaching an annual cost of about EUR 100,000 in cases of severe neurological damage). Furthermore, vaccination against meningococcus B in adolescence proved cost-effective. The study highlights the need to actively offer the anti-MenB vaccination during adolescence at a national level. This would make it possible to avoid premature deaths and reduce the high costs borne by the National Health Service and by society of supporting survivors who suffer temporary and/or permanent sequelae.

Invasive meningococcal disease in Italy: from analysis of national data to an evidence-based vaccination strategy

Introduction

Invasive meningococcal disease (IMD) is one of the most severe vaccine-preventable disease not yet under control. In Italy, although different anti-meningococcal vaccines are available, their offer among regions is heterogeneous. The aim of this study is to describe the epidemiology of IMD in Italy based on analysis of national surveillance data for 2011-2017 to optimize the vaccination strategy.

Methods

IMD surveillance data from the Italian National Health Institute were analysed. Microsoft Excel was used to present trend analysis, stratifying by age and serogroups.

Results

In Italy, during the period 2011-2017, the incidence of IMD increased from 0.25 cases/100,000 inhabitants in 2011 to 0.33 cases/100,000 in 2017. Most cases after 2012 were caused by non-B serogroups. The number of cases in subjects aged 25-64 years increased steadily after 2012 (36 cases in 2011, 79 in 2017), mostly due to non-B serogroups, representing more than 65% of cases in those aged 25+ years.

Conclusions

In the period from 2011 to 2017, the incidence of IMDs increased in Italy. The increase, probably due also to a better surveillance, highlights the importance of the disease in the adult population and the high level of circulation of non-B serogroups in particular after 2012. Our analysis supports an anti-meningococcal vaccination plan in Italy that should include the highest number of preventable serogroups and be aimed at vaccinating a wider population through a multicohort strategy.

A Comprehensive Review of Meningococcal Disease Burden in India

INTRODUCTION

Meningococcal disease caused by Neisseria meningitidis has a high case fatality rate. Of 12 distinct serogroups, A, B, C, W-135 (W) and Y cause the majority of infections. The meningococcal disease burden and epidemiology in India are not reliably known. Hence, we performed a narrative review with a systematically conducted search to summarize information on meningococcal disease burden and epidemiology and vaccination recommendations for meningococcal disease in India.

METHODS

A search of Medline and Embase databases was undertaken to identify relevant publications published in the last 25 years.

RESULTS

Results from 32 original publications, 11 of which were case reports, suggest a significant burden of meningococcal disease and related complications. Meningococcal disease is increasingly reported among adolescents and adults, and large outbreaks have been reported in this population. Meningococcal disease in India is caused almost exclusively by serogroup A; serogroups B, C, W and Y have also been documented. Meningococcal disease burden data remain unreliable because of limited disease surveillance, insufficient laboratory capacity, misdiagnosis and prevalence of extensive antibiotic use in India. Lack of access to healthcare also increases under-reporting, thus bringing the reliability of the data into question. Conjugate meningococcal vaccines are being used for disease prevention by national governments and immunization programs globally. In India, meningococcal vaccination is recommended only for certain high-risk groups, during outbreaks and for international travelers such as Hajj pilgrims and students pursuing studies abroad.

CONCLUSION

Meningococcal disease is prevalent in India but remains grossly underestimated and under-reported. Available literature largely presents outbreak data related to serogroup A disease; however, non-A serogroup disease cases have been reported. Reliable epidemiologic data are urgently needed to inform the true burden of endemic disease. Further research into the significance of meningococcal disease burden can be used to improve public health policy in India. Fig. 1 Plain language summary.

A clinical update on vaccines: focus on determinants of under-immunization and special considerations for adolescents

PURPOSE OF REVIEW

The current article reviews recent literature related to pediatric and adolescent vaccination, specifically focusing on social determinants of under-immunization, expanding adolescent immunization rates, and new recommendations surrounding the meningococcal serotype B vaccine (MenB).

RECENT FINDINGS

Vaccine refusals and vaccine-preventable diseases have been rising in some parts of the world, and appear to be linked to household factors, such as a family's socioeconomic status. Adolescents have lower immunization rates than younger children. Newer vaccines targeted at adolescents, such as the MenB vaccine, have yet to be widely accepted by pediatric providers, parents, and patients.

SUMMARY

Pediatric healthcare providers should attempt to increase local immunization rates by vaccinating children at all eligible office visits and utilizing electronic health record decision-support tools. Although the number of families who choose not to vaccinate their children may be rising, providers can be innovative (e.g. incorporate digital vaccine reminder systems) and increase their familiarity with new vaccine recommendations to continue to prevent serious vaccine-preventable diseases.

Papel del estado de portador en el control de enfermedades infecciosas y su relación con la vacunación

El reservorio natural de Streptococcus pneumoniae, Neisseria meningitidis y Bordetella pertussis es el ser humano. De este modo, en caso de disponer de vacunas efectivas que impidieran la colonización por estas bacterias se podría interrumpir su transmisión. La respuesta inmune frente a los antígenos capsulares de Streptococcus pneumoniae condiciona el estado de portador de los diferentes serotipos. La vacuna neumocócica polisacárida 23 valente (PPV23) induce una respuesta inmune T independiente que es de corta duración y no previene la colonización. Por el contrario las vacunas conjugadas 10 valente (PCV10V) y 13 valente (PCV13) generan una inmunidad T dependiente que si reduce la colonización por los serotipos incluidos en su composición. Por este motivo las vacunas conjugadas proporcionan inmunidad de grupo. La vacunación de adolescentes frente a Neisseria menigintidis puede modificar el patrón de transmisión de la infección con una reducción de la incidencia en niños. En la actualidad se dispone de vacunas conjugadas frente a meningococo C, conjugadas tetravalantes frente a los serogrupos ACWY y de proteínas recombinantes frente a meningococo B. La inmunidad de grupo generada por vacunas conjugadas ha sido demostrada para Neisseria menigintidis C. Desafortunadamente existe escasa evidencia del impacto de las vacunas frente a meningococo B en la reducción del estado de portador entre adultos jóvenes. La infección natural por Bordetella pertussis estimula la producción de linfocitos T de memoria e induce una intensa respuesta de IgA secretora en la nasofaringe. En contraste con la infección natural y con las vacunas de células completas las actuales vacunas acelulares, no generan inmunidad en mucosas y no otorgan inmunidad de grupo. En un intento de resolver este problema se están desarrollando vacunas alternativas frente a Bordetella pertussis como las nuevas de células completas y las vivas atenuadas.