Underestimation of Invasive Meningococcal Disease in Italy

Invasive meningococcal disease in South-Eastern European countries: Do we need to revise vaccination strategies?

Invasive meningococcal disease (IMD) is an acute life-threatening infection caused by the gram-negative bacterium, Neisseria meningitidis. Globally, there are approximately half a million cases of IMD each year, with incidence varying across geographical regions. Vaccination has proven to be successful against IMD, as part of controlling outbreaks, and when incorporated into national immunization programs. The South-Eastern Europe Meningococcal Advocacy Group (including representatives from Croatia, the Czech Republic, Greece, Hungary, Poland, Romania, Serbia, Slovenia and Ukraine) was formed in order to discuss the potential challenges of IMD faced in the region. The incidence of IMD across Europe has been relatively low over the past decade; of the countries that came together for the South-Eastern Meningococcal Advocacy Group, the notification rates were lower than the European average for some country. The age distribution of IMD cases was highest in infants and children, and most countries also had a further peak in adolescents and young adults. Across the nine included countries between 2010 and 2020, the largest contributors to IMD were serogroups B and C; however, each individual country had distinct patterns for serogroup distribution. Along with the variations in epidemiology of IMD between the included countries, vaccination policies also differ.

Ventricular Tachycardia Crisis: Assessing Norepinephrine vs. Stress Steroids in the Battle Against Waterhouse-Friderichsen Syndrome With Distributive Shock

Waterhouse-Friderichsen syndrome (WFS) is a rare but life-threatening complication associated with acute hemorrhagic necrosis of the adrenal glands, primarily linked to meningococcal infection. This report details the case of a 62-year-old female with HIV/AIDS and substance misuse who presented with ventricular tachycardia and hemodynamic instability. Subsequent evaluation revealed WFS in the context of disseminated meningococcal infection. The case highlights the diversity of WFS manifestations and the diagnostic challenges, particularly in patients with comorbidities. Managing WFS involves a delicate balance of steroids and vasopressors, necessitating a multidisciplinary approach. Timely diagnosis and intervention are critical in mitigating the high mortality associated with this syndrome.

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.

A policy review of the introduction of the MenACWY vaccine in toddlers across multiple countries

INTRODUCTION

Immunization is the best strategy to protect individuals from invasive meningococcal disease (IMD). To support decision-making around immunization, this paper considers what has led four countries and regions of two more to introduce the quadrivalent MenACWY vaccine in toddlers (ages 12-24 months).

AREAS COVERED

A narrative literature review was conducted to identify countries that have introduced a MenACWY vaccination program for toddlers. Information from peer-reviewed publications, reports, and policy documents for each identified country was extracted. Australia, Chile, the Netherlands, Switzerland, and regions of Italy and Spain have introduced the MenACWY vaccine in their toddler programs, driven by the rising incidence of MenW and MenY and the vaccine's ability to provide protection against other serogroups. Australia and the Netherlands considered the economic impacts of implementing a MenACWY toddler vaccination program. Vaccination uptake and effects are reported for three countries; however, in two, isolating the vaccine's effect from the collateral effect of COVID-related measures is difficult.

EXPERT OPINION

Increased convergence of vaccination policies and programs is needed internationally, as IMD recognizes no borders.PL AIN LANGUAGE SUMMARYVaccination is the best defense against meningitis, a deadly disease. While someone of any age can contract it, children 0-24 months of age are disproportionately affected. The increasing number of cases of meningitis has led four countries plus regions of two more to introduce into their vaccination schedules for toddlers (ages 12-24 months) a vaccine that protects against four different serogroups rather than one serogroup alone. This paper considers what has driven that shift.

Evaluation of Multiplex Real-time PCR and WHO Criteria for Diagnosing Childhood Bacterial Meningitis in a Tertiary Referral Hospital in Iran

Background: Childhood bacterial meningitis (BM) requires prompt and precise diagnosis to provide proper treatment and decline mortality and morbidity. Objectives: We aimed to evaluate the World Health Organization (WHO) criteria and polymerase chain reaction (PCR) for diagnosing BM in children admitted to a tertiary referral hospital in Shiraz, southern Iran. Materials: We included all 492 children aged one month to 17 years suspected of meningitis who had cerebrospinal fluid (CSF) leukocytosis admitted to Nemazi Hospital from August 2016 to September 2017. The CSF specimens were examined for routine analysis, Gram staining, and culture. A multiplex real-time PCR was used to identify Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis in the CSF samples. Seven viruses were also investigated using real-time PCR. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated using the WHO criteria and the multiplex real-time PCR results. Results: Seventy-four CSF samples had leukocytosis. Nineteen (22.9%) patients had BM caused by S. pneumoniae (n = 14), Hib (n = 2), Salmonella enterica (n = 2), and N. meningitidis (n = 1). The PCR test detected all cases, except for two with Salmonella meningitis (sensitivity 89.4%, specificity 100%, PPV 100%, and NPV 96%). The WHO criteria detected all cases, except three who received antibiotics at least four days before performing lumbar puncture (sensitivity 84.2%, specificity 98.2%, PPV 94.1%, and NPV 94.7%). Enterovirus was the most common viral etiology (6.75%). Conclusions: The WHO criteria and the multiplex real-time PCR had high accuracy in our setting, and their use could decrease the antibiotic over-prescription in febrile children suspected of meningitis.

Real-time polymerase chain reaction on filter paper spotted samples: a gateway to molecular diagnosis of invasive bacterial diseases for rural areas in low-income countries

BACKGROUND

Bacterial culture is the gold standard for the diagnosis of invasive bacterial diseases (IBDs) but molecular methods are more specific and sensitive. Fresh liquid samples (FLSs) show patent limitations for shipping and storage. We aimed to evaluate the sensitivity and specificity of real-time polymerase chain reaction (PCR) performed on dried sample spots (DSSs) obtained from different biological fluids compared with real-time PCR or culture performed on FLSs.

METHODS

FLSs positive for Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus, Bordetella pertussis and/or Pseudomonas aeruginosa were spotted on filter paper. Real-time PCR was performed on both FLSs and DSSs and results were compared. The stability of the DSS results over time was evaluated.

RESULTS

Real-time PCR performed on 114 DSSs showed a specificity of 99.1% and a sensitivity of 91.2% for IBD diagnosis. A positive correlation was found between FLS cycle threshold (Ct) and DSS Ct (r=0.84; r2=0.71) with the Pearson statistical test and Bland-Altman analysis showing that 95% of the specimens were within agreeable limits. Although we observed a trend towards signal reduction over time in the DSSs, there was no statistical evidence of an increase in Ct values. Real-time PCR on DSSs was 2.2 times more sensitive than culture.

CONCLUSIONS

Real-time PCR applied to DSSs may be a useful approach in different situations, such as IBD diagnosis, both for rural areas of low-income countries and family practitioners in various settings.

Molecular typing of group B Neisseria meningitidis'subcapsular antigens directly on biological samples demonstrates epidemiological congruence between culture-positive and -negative cases: A surveillance study of invasive disease over a 13-year period

BACKGROUND

Surveillance of serogroup B Neisseria meningitidis (MenB) subcapsular antigen variant distribution in invasive disease (IMD) is fundamental for multicomponent vaccine coverage prediction. IMD incidence in Tuscany in 2018 was 0.37/100,000 inhabitants, with MenB representing 57% of cases. More than 50% of MenB responsible for IMD cannot be grown in culture, and molecular characterization of these cases is often lacking. The aim of the present study was to describe the distribution of MenB subcapsular antigens, comparing their distribution in culture-positive and culture-negative cases.

METHODS

Molecular data regarding clonal complexes and subcapsular antigen variants of the 55 MenB-IMD occurring in Tuscany from 2007 to 2019 were made available, and their distribution between culture-positive and culture-negative cases was compared. Genetic-MATS and MenDeVAR prediction systems were used to assess multicomponent vaccine coverage predictions.

RESULTS

Culture-positive and culture-negative cases presented a similar percentage representation of fHbp subfamilies. Clonal complex 162 was almost constantly associated with fHbp B231/v1.390, Neisserial-heparin-binding-antigen (NHBA) peptide 20, and PorinA P1.22,14 (BAST-3033): these were the most represented antigenic variants, both in culture-positive and culture-negative groups. Point-estimate 4CMenB coverage prediction was 88.5% (84.6%-92.3%).

CONCLUSIONS

Our data demonstrate that non-cultivable meningococci, responsible for IMD, possess genetic variants of subcapsular antigens that are representative of what has been observed in culture. The vaccine-related antigenic epidemiology of MenB is thus similar in both groups. One of the first on-field applications of gMATS and MenDeVAR identifies their major advantage in their accessibility and in the possibility of dynamic data implementation that must be pursued continuously in the future.

Epidemiological study of bacterial meningitis in Tunisian children, beyond neonatal age, using molecular methods: 2014-2017

BACKGROUND

Since the 1990s, the epidemiology of bacterial meningitis worldwide has changed thanks to vaccination. In Tunisia, the main causative pathogens were Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae serotype b (Hib). Only Hib vaccination was available during our study period.

OBJECTIVES

We performed a laboratory case report based-study of suspected bacterial meningitis in Northern Tunisia from January 2014 to June 2017.

METHODS

CSF samples obtained from children beyond neonatal age with suspicion of meningitis were tested by two real time PCRs, targeting pneumococcus, meningococcus and Hib, and conventional methods.

RESULTS

Using real-time PCR, 63 were positive including ten supplementary cases compared to conventional methods. A general decrease of bacterial meningitis cases was demonstrated comparing to previous data. Pneumococcus was predominant (69.84%) followed by meningococcus (28.57%) and Hib (1.59%). The main serotypes were 14, 19F, 6B and 23F for pneumococcus and serogroup B for meningococcus. Most cases occurred during cold season and children under one year were the most affected by bacterial meningitis.

CONCLUSION

Our study suggests the predominance of pneumococcal cases. It may provide valuable data on meningitis epidemiology before the introduction of pneumococcal vaccine, which may be useful for future evaluation.

Effectiveness and Impact of the 4CMenB Vaccine against Group B Meningococcal Disease in Two Italian Regions Using Different Vaccination Schedules: A Five-Year Retrospective Observational Study (2014-2018)

Background: A few years after the introduction in Italy of a four-component anti-meningococcal B vaccine (4CMenB), we evaluated the effectiveness and impact of vaccination in two regions using different schedules (2, 4, 6, 12 months in Tuscany vs. 7, 9, 15 months in Veneto) through an observational retrospective study. Methods: Vaccination started in 2014 in Tuscany and in 2015 in Veneto; the data collected referred to the period 2006–2018 for Tuscany and 2007–2018 for Veneto. Cases of invasive meningococcal disease due to N. Meningitidis B were identified by culture and/or real-time PCR. Results: In Tuscany, pre-vaccine incidence was 1.96 (95% CL 1.52; 2.40) and dropped to 0.62 (95% CL 0.60; 0.64) in the post-4CMenB era. Evaluating only vaccinated children, post-4CMenB incidence was 0.12 (95% CL 0.08; 0.15). In Veneto pre-vaccine incidence was 1.94 (95% CL 1.92; 1.96) and dropped to 1.34 (95% CL 1.31; 1.38) in the post-4CMenB era. In the vaccinated population, MenB incidence was 0.53 (95% CL 0.50; 0.56). Vaccine effectiveness was 93.6% (95% CL 55.4; 99.1) in Tuscany and 91.0% (95% CL 59.9; 97.9) in Veneto, with mean vaccine coverages of 83.9% and 81.7%, respectively. The overall impact (evaluating both vaccinated and unvaccinated children) was 0.68 (95% CL 0.10; 0.89) in Tuscany and 0.31 (95% CL −0.56; 0.69) in Veneto; the total impact (evaluating only vaccinated children) was 0.94 (95% CL 0.56; 0.99) and 0.90 (95% CL 0.57; 0.97), respectively. The relative case reduction (RCR) was 65% in Tuscany and 31% in Veneto. Considering the vaccinated population, the RCR was equal to 91% and 80%, respectively. Conclusion: In conclusion, 4CMenB appears to have a very high effectiveness in Italy; the impact of vaccination appears greater where the immunization program is started early.

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.

Methods to evaluate serogroup B meningococcal vaccines: From predictions to real-world evidence

Serogroup B meningococci (MenB) remain a prominent cause of invasive meningococcal disease (IMD). The protein-based multicomponent 4CMenB and the bivalent MenB-FHbp are the only currently available vaccines against MenB-caused IMD. Efficacy studies are not possible, due to the low incidence of IMD. Therefore, the vaccines' immunogenicity has been evaluated against several target strains chosen to quantify complement-mediated killing induced by each vaccine component in the serum bactericidal antibody assay. However, due to the wide genetic diversity and different expression levels of vaccine antigens across MenB strains, vaccine performance may differ from one strain to another. Here, we review the methods used to predict MenB strain coverage for 4CMenB and MenB-FHbp. Phenotypic assays such as the meningococcal antigen typing system (MATS, 4CMenB-specific) and the flow cytometric meningococcal antigen surface expression assay (MEASURE; MenB-FHbp-specific) were developed. Genomic approaches are also available, such as genetic MATS (gMATS) and the Bexsero antigen sequence type (BAST) scheme, both 4CMenB-specific. All methods allow tentative predictions of coverage across MenB strains, including that afforded by each vaccine antigen, and are rapid and reproducible. Real-world data on vaccine effectiveness are needed to confirm predictions obtained by these methods.

Recurrent invasive meningococcal infections - quantifying the risk, Germany, 2002 to 2018

Introduction

Invasive meningococcal disease (IMD) is a rare condition with a high case fatality rate. While most patients suffer from one single episode in life, there is anecdotal evidence for recurrent infection.

Aim

The German National Reference Laboratory for Meningococci and Haemophilus influenzae (NRZMHi) analysed IMD cases from 2002 to 2018 to retrospectively quantify the risk of recurrent infection.

Methods

Recurrent IMD was defined as detection of Neisseria meningitidis in a sample of the same patient more than 30 days after the first episode of IMD.

Results

Among 5,854 patients with a median observation period of 9.4 years, 14 suffered a second IMD episode and one patient a third one. The risk of a recurrent IMD was 29.4 per 100,000 person-years for survivors of the first episode. Rare serogroups (Y, W, E and Z) were more common in patients with recurrent IMD (p < 0.0001).

Discussion

Patients surviving IMD were at least at a 50-fold risk of another IMD episode compared with the general population. The study most likely underestimated the risk of recurrent infection. Increased risk may be due to undiagnosed complement deficiencies. The high risk of re-infection argues for vaccination of patients who have survived IMD.

Neisseria meningitidis with H552Y substitution on rpoB gene shows attenuated behavior in vivo: report of a rifampicin-resistant case following chemoprophylaxis

We present the first Italian reported case of an invasive meningococcal disease with rifampicin-resistance (Rif-R)secondary to chemoprophylaxis. The case is entered in a cluster of two IMDs registered in Tuscany, Italy, in November 2019 caused by two non-differentiable group-C Neisseria meningitidis belonging to ST-11 clonal-complex. The contact case, differently from the index, harbored H552Y mutation on rpoB gene which is known to confer Rif-R putting a high-cost fee on bacterial fitness. The extremely mild clinical presentation in the contact can constitute an in vivo demonstration of the virulence attenuation observed in vitro for H552Ymutants. Clinicians should be aware of the possibility of secondary cases with induced Rif-R and keep a high level of suspicion on contacts who received rifampicin-chemoprophylaxis. Molecular characterization of Rif-R should be performed routinely directly on biological samples and not only on isolates, in order to rapidly detect rare cases of resistance and consequently modify chemoprophylaxis for contacts.

Invasive Haemophilus influenzae Type b Disease in the Post Hexavalent Era: Ten Years of Molecular Surveillance in Tuscany

BACKGROUND

The epidemiologic characteristics of invasive Haemophilus influenzae type b disease (HIBD) have markedly changed since the introduction of the Haemophilus influenzae type b (Hib) conjugate vaccine worldwide. The immunization schedule against Haemophilus influenzae type b differs in Europe.

METHODS

This is a retrospective observational study which evaluates all the data included in the molecular surveillance register for invasive infectious diseases at the Laboratory of Molecular Diagnosis at Meyer Children's University Hospital from December 2008 to December 2018 with a diagnosis of invasive HIBD in children <5 years of age.

RESULTS

We identified 4 cases of HIBD: all the cases presented signs or symptoms of invasive infection and the H. influenzae type b was identified in cerebrospinal fluid, or blood or bronchoalveolar lavage by molecular test. The crude incidence for Hib invasive disease in Tuscany is 0.26/100,000 p-y in children younger than 5 years, significantly different from the incidence rate before the introduction of the Hib vaccination. Vaccination effectiveness can be estimated at 97.9% and the impact of hexavalent (2p+1) vaccine at 99.6%.

CONCLUSIONS

This work confirms the high impact of the hexavalent vaccine 2p+1 schedule for HIBD in children <5 years, emphasizing the role of molecular test for HIBD diagnosis and surveillance.

Interconnected clusters of invasive meningococcal disease due to Neisseria meningitidis serogroup C ST-11 (cc11), involving bisexuals and men who have sex with men, with discos and gay-venues hotspots of transmission, Tuscany, Italy, 2015 to 2016

In 2015 an increased incidence of invasive meningococcal disease due to serogroup-C (MenC) occurred in Tuscany, Italy. This led the Regional Health Authority of Tuscany to implement a reactive immunisation campaign and to launch an epidemiological field investigation aiming to address targeted immunisation interventions. In 2011–14, 10 MenC cases had been reported compared with 62 cases in 2015–16. The case fatality rate was 21% (n = 13) and 51 cases (82.3%) were confirmed as C:P1.5–1,10–8:F3–6:ST-11(cc11). Overall, 17 clusters were recognised. Six discos and four gay-venues were found to have a role as transmission-hotspots, having been attended by 20 and 14 cases in the 10 days before symptoms onset. Ten and three cases occurred, respectively, among men who have sex with men (MSM) and bisexual individuals, who were involved in 11 clusters. In addition, heterosexual cases (n = 5) attending gay-venues were also found. Secondary cases were not identified. Molecular typing indicated close relationship with MenC clusters recently described among gay, bisexual and other MSM in Europe and the United States, suggesting a possible international spread of the serogroup-C-variant P1.5–1,10–8:F3–6:ST-11(cc11) in this population-group; however, epidemiological links were not identified. In December 2016, a targeted vaccination campaign involving discos and lesbian, gay, bisexual, and transgender (LGBT) associations was implemented. During 2017, 10 cases of MenC occurred, compared with 32 and 30 cases reported in 2015 and 2016 respectively, suggesting the effectiveness of the reactive and targeted immunisation programmes.

Impact of the 13-Valent Pneumococcal Conjugate Vaccine on Severe Invasive Disease Caused by Serotype 3 Streptococcus Pneumoniae in Italian Children

The effectiveness and impact of the 13-valent pneumococcal conjugate vaccine (PCV13) against invasive pneumococcal diseases (IPD) due to serotype 3 (ser3) has been questioned. However, the impact of PCV13 on different clinical presentations of ser3-IPD has not been studied so far. The impact of PCV13 on different clinical presentations of ser3-IPD in a population of Italian children aged 0–8 years was evaluated, comparing pre- and post-PCV13 introduction period. Real-time polymerase chain reaction (PCR) was used for the diagnosis and serotyping of IPD. During the observation period (1 January 2006–1 August 2018), ser3 was detected in 60/284 (21.1%) children under 8 with serotyped IPD. The incidence of sepsis and meningitis was 0.24 per 1,000,000 person-years (p-y) in pre-PCV13 and 0.02 per 1,000,000 p-y in post-PCV13. No cases occurred in vaccinated children. In the post-PCV13 period, case reduction was 13% for all ser3 IPD and 92% for sepsis and meningitis. Vaccination impact may be underestimated due to significant improvement in pneumococcal surveillance in post-PCVC13. Our data suggest a significant impact of PCV13 on meningitis and sepsis due to ser3 and a lower impact against pneumonia. While waiting for increasingly effective anti-pneumococcal vaccines, PCV13, which guarantees protection against the most severe clinical presentations of ser3-IPD, is currently the most effective prevention option available.

Significant impact of pneumococcal conjugate vaccination on pediatric parapneumonic effusion: Italy 2006-2018

Etiology and serotyping of parapneumonic effusion (PPE) and the impact of vaccination was evaluated over a 12-year period, before and after the PCV13 introduction (2011) for Italian children From 0 to 16 years of age. Five hundred and two children were evaluated; 226 blood and 356 pleural fluid samples were obtained and tested using Realtime-PCR and culture. In the pre-PCV13 era S. pneumoniae was the most frequent pathogen identified (64/90; 71.1%) with a large predominance of serotypes 1 (42.4%), 3 (23.7%), 7F (5.1%) and 19A (11.9%). The impact of vaccination, calculated on children 0-8 years of age, demonstrated a significant reduction of PPE: with an incidence rate of 2.82 (95%CL 2.32-3.41) in the pre-PCV13 era and an age-standardized rate (ASR) of 0.66 (95% CL 0.37-1.99) in the post-PCV13 era, p < 0.0001. No increase in non-PCV13 serotypes was recorded. S. pneumoniae remained the most frequent pathogen identified in the post-PCV13 era in unvaccinated children with an unchanged serotype distribution: respectively 26/66 (39.4%), 25/66 (37.9%), 5/66 (7.6%), and 4/66 (6.1%) for 1, 3, 7F and 19A. On the other hand 7F and 19A disappeared in vaccinated children and serotype 1 and 3 decreased by 91.8% and 31.5%, respectively. Realtime PCR was significantly more sensitive than culture both in pleural fluid (79.7% vs 12.5%) and in blood (17.8% vs 7.4%). In conclusion, our findings indicate that routine immunization with PCV13 has significantly reduced the burden of childhood PPE in vaccinated children, without increasing PPE due to other bacteria and without serotype shift. Moreover, the impact of PCV13 may be underestimated due to the increase in pneumococcal surveillance in Italy. Data has also shown that Real-time PCR is an essential tool to better define the etiology of PPE and to monitor vaccination plans. Longer studies will be necessary to evaluate the role of herd protection in PPE prevention.

Culture and Real-time Polymerase Chain reaction sensitivity in the diagnosis of invasive meningococcal disease: Does culture miss less severe cases?

BACKGROUND

Invasive meningococcal disease (IMD) is a highly lethal disease. Diagnosis is commonly performed by culture or Realtime-PCR (qPCR).

AIMS

Our aim was to evaluate, retrospectively, whether culture positivity correlates with higher bacterial load and fatal outcome. Our secondary aim was to compare culture and qPCR sensitivity.

METHODS

The National Register for Molecular Surveillance was used as data source. Cycle threshold (CT), known to be inversely correlated with bacterial load, was used to compare bacterial load in different samples.

RESULTS

Three-hundred-thirteen patients were found positive for Neisseria meningitidis by qPCR, or culture, or both; 41 died (case fatality rate 13.1%); 128/143 (89.5%) blood samples and 138/144 (95.8%) CSF were positive by qPCR, 37/143 (25.9%) blood samples and 45/144 (31.2%) CSF were also positive in culture. qPCR was 3.5 times (blood) or 3.1 times (CSF) more sensitive than culture in achieving a laboratory diagnosis of IMD (OR 24.4; 95% CI 12.2-49.8; p < .10-4; Cohen's κ 0.08 for blood and OR 49.0; 95% CI 19.1-133.4; p<10-4; Cohen's κ 0.02; for CSF). Positivity of culture did not correlate with higher bacterial loads in blood (mean CT 27.7±5.71, and CT 28.1±6.03, p = 0.739 respectively in culture positive or negative samples) or in CSF (mean CT 23.1±4.9 and 24.7±5.4 respectively in positive or negative CSF samples, p = 0.11).CT values in blood from patients who died were significantly lower than in patients who survived (respectively mean 18.0, range 14-23 and mean 29.6, range 16-39; p<10-17). No deaths occurred in patients with CT in blood over 23. Positive blood cultures were found in 10/25 (40%) patients who died and in 32/163 (19.6%) patients who survived, p = 0.036, OR 2.73; 95% CL 1.025-7.215), however 60% of deaths would have remained undiagnosed with the use of culture only.

CONCLUSIONS

In conclusion our study demonstrated that qPCR is significantly (at least 3 times) more sensitive than culture in the laboratory confirmation of IMD. The study also demonstrated that culture negativity is not associated with lower bacterial loads and with less severe cases. On the other side, in patients with sepsis, qPCR can predict fatal outcome since higher bacterial load, evaluated by qPCR, appears strictly associated with most severe cases and fatal outcome. The study also showed that molecular techniques such as qPCR can provide a valuable addition to the proportion of diagnosed and serotyped cases of IMD.

Genetic Meningococcal Antigen Typing System (gMATS): A genotyping tool that predicts 4CMenB strain coverage worldwide

BACKGROUND

The Meningococcal Antigen Typing System (MATS) was developed to identify meningococcus group B strains with a high likelihood of being covered by the 4CMenB vaccine, but is limited by the requirement for viable isolates from culture-confirmed cases. We examined if antigen genotyping could complement MATS in predicting strain coverage by the 4CMenB vaccine.

METHODS

From a panel of 3912 MATS-typed invasive meningococcal disease isolates collected in England and Wales in 2007-2008, 2014-2015 and 2015-2016, and in 16 other countries in 2000-2015, 3481 isolates were also characterized by antigen genotyping. Individual associations between antigen genotypes and MATS coverage for each 4CMenB component were used to define a genetic MATS (gMATS). gMATS estimates were compared with England and Wales human complement serum bactericidal assay (hSBA) data and vaccine effectiveness (VE) data from England.

RESULTS

Overall, 81% of the strain panel had genetically predictable MATS coverage, with 92% accuracy and highly concordant results across national panels (Lin's accuracy coefficient, 0.98; root-mean-square deviation, 6%). England and Wales strain coverage estimates were 72-73% by genotyping (66-73% by MATS), underestimating hSBA values after four vaccine doses (88%) and VE after two doses (83%). The gMATS predicted strain coverage in other countries was 58-88%.

CONCLUSIONS

gMATS can replace MATS in predicting 4CMenB strain coverage in four out of five cases, without requiring a cultivable isolate, and is open to further improvement. Both methods underestimated VE in England. Strain coverage predictions in other countries matched or exceeded England and Wales estimates.

Is primary meningococcal arthritis in children more frequent than we expect? Two pediatric case reports revealed by molecular test

Background

Primary meningococcal arthritis is a rare infectious disease that occurs in less than 3% of meningococcal infections and is characterized by arthritis without meningitis, fever, rash, or hemodynamic instability Barahona [Case Rep Orthop 4696014:2017 ]. There are no validated clinical criteria that can be used for the diagnosis. We present two pediatric cases of atypical presentation of meningococcal disease revealed by molecular tests.

Case presentation

The clinical presentation of the two children (6- and 9-years-old) was characterized by signs of arthritis. By Real Time Polymerase Chain Reaction (RT-PCR), we identified N. meningitidis serogroup Y in the joint fluid in both cases. After specific antimicrobial treatment, the clinical conditions of the two patients quickly improved during hospitalization. Conclusions. We believe that the incidence of meningococcal arthritis could be underestimated in those settings where the use of RT-PCR is limited. Clearer data on the incidence of meningococcal disease would help to design specific treatments and the best possible national vaccine strategies [Fiji Sci Rep 23:39784, 2016, J Infect 67:385-90, 2013].

Do Tuscan people adhere to meningococcal C vaccination during an emergency campaign?

OBJECTIVES

Tuscany region (Italy) recorded a rise in the number of meningococcal disease cases between January 2015 and February 2016, (52 cases) compared to 2014 (16 cases). The aim of this study was to describe the emergency meningococcal C (MenC) vaccination programme in Tuscany and the population's adherence to the activities performed in the Local Health Unit (LHU) of Florence.

METHODS

The MenC vaccination programme and the planning of the prevention and communication activities were analysed in the LHU of Florence. As an indicator of population's adherence, the vaccination coverage (VC) during the emergency campaign was investigated and adverse drug reactions (ADR) surveillance was reported.

RESULTS

The communication campaign included a dedicated toll-free telephone number, press releases (newspapers, radio, television, websites), and informative letters addressed to mayors, secondary schools, and sports associations. Citizens aged 11-20 years were the primary target of the campaign. Due to the high incidence of cases among older people, the vaccination was extended to subjects over 45 years. The population's adherence to the vaccination campaign was satisfactory: VC reached 47.1% for the primary target. The ADR reporting rate (3.1/10,000) on meningococcal vaccine in our study confirmed the safety of the vaccination.

CONCLUSIONS

In 2017, only 10 cases of invasive meningococcal diseases (IMD) were reported, suggesting the effectiveness of the immunization campaign. Similar VC during emergency MenC vaccination programmes have been reached in other Italian regions and other EU countries, too. The achievement of greater vaccination coverage is restricted by a sentiment of hesitancy towards vaccines among the general population.

Invasive Meningococcal Disease due to group C N. meningitidis ST11 (cc11): The Tuscany cluster 2015-2016

OBJECTIVES

To describe the cluster of MenC ST11 Invasive Meningococcal Disease (IMD) occurred in Tuscany in the years 2015-2016.

METHODS

A retrospective charts analysis of clinical, epidemiological and microbiological aspects of documented IMD was performed. Prognostic factors for death were evaluated.

RESULTS

Sixty-one patients with IMD in the 2015-2016 period were documented: 28 had meningococcemia, 24 meningitis plus meningococcemia and 9 meningitis. MenC ST11 (cc11) was identified in 48/54 (89%) of the tested strains. All patients, with the exception of three very early death, received timely and appropriate antibiotic therapy and, in selected case, adjunctive therapy with steroids and Pentaglobin®. Forty-one patients recovered (67.3%, mean age: 26 years), 7 had permanent sequelae (11.3%, mean age 31 years) and 13 died (21.3%; mean age: 46 years). In a multivariate analysis, septic shock, purpura fulminans and advanced age were negative prognostic factors, while emergency admittance to a tertiary-care, university hospital, positively influenced the survival rate. The epidemiological analysis of the cluster identified close contacts and recreational environments such as discos as hotspot for MenC transmission. After a massive vaccination campaign, the number of MenC cases reported in Tuscany in 2017 decreased to 10, with no death.

CONCLUSIONS

Vaccination campaign of key populations together with the need for rapid and qualified emergency care of the affected patients seems to be the main lesson learned by the MenC ST11 Tuscany epidemic.

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.

Invasive meningococcal disease in the Veneto region of Italy: a capture-recapture analysis for assessing the effectiveness of an integrated surveillance system

BACKGROUND

Epidemiology of Neisseria meningitidis has been changing since the introduction of universal vaccination programmes against meningococcal serogroup C (MenC) and meningococcal serogroup B (MenB) has now become dominant. This study aimed to analyse the cases reported in institutional data recording systems to estimate the burden of invasive meningococcal diseases (IMDs) and assess the effectiveness of surveillance in Veneto region (Italy).

METHODS

Analysis was performed from 2007 to 2014 on data recorded in different systems: Mandatory Notification System, National Surveillance of Invasive Bacterial Diseases System and Laboratories Surveillance System (LSS), which were pooled into a combined surveillance system (CSS) and hospital discharge records (HDRs). A capture-recapture method was used and completeness of each source estimated. Number of cases with IMD by source of information and year, incidence of IMD by age group, case fatality rate (CFR) and distribution of meningococcal serogroups by year were also analysed.

RESULTS

Combining the four data systems enabled the identification of 179 confirmed cases with IMD, achieving an overall sensitivity of 94.7% (95% CI: 90.8% to 98.8%), while it was 76.7% (95% CI: 73.6% to 80.1%) for CSS and 77.2% (95% CI: 74.1% to 80.6%) for HDRs. Typing of isolates was done in 80% of cases, and 95.2% of the typed cases were provided by LSS. Serogroup B was confirmed in 50.3% of cases. The estimated IMD notification rate (cases with IMD diagnosed and reported to the surveillance systems) was 0.48/100 000 population, and incidence peaked at 6.2/100 000 in children aged <1 year old (60.9% due to MenB), and increased slightly in the age group between 15 and 19 years (1.1/100 000). A CFR of 14% was recorded (8.7% in paediatric age).

CONCLUSIONS

Quality of surveillance systems relies on case ascertainment based on serological characterisation of the circulating strains by microbiology laboratories. All available sources should be routinely combined to improve the epidemiology of IMD and the information used by public health departments to conduct timely preventive measures.

[Advances in diagnostic microbiology : Opportunities and limitations]

In the light of ever increasing problems related to the emergence of multidrug-resistant bacteria, rapid microbiological diagnostics are of growing importance. Timely pathogen detection and availability of susceptibility data are essential for optimal treatment, but are even more crucial for de-escalation of broad spectrum empiric therapies. Medical microbiology is, thus, an integral part of antimicrobial stewardship programs. Traditional microbiological techniques for species identification and susceptibility testing rely on bacterial growth and are, thus, characterized by inherent slowness. Time-to-report is usually 48 h or longer, and typically delays optimization of therapeutic regimens. Constant improvement of available techniques (e. g., molecular methods) and introduction of novel methods (e. g., matrix-assisted laser desorption ionization time-of-flight [MALDI-ToF] mass spectrometry) have fundamentally changed diagnostic procedures. As a consequence, sensitivity and specificity as well as time-to-report have been dramatically improved. In this manuscript, key methodological advances in medical microbiology are discussed, emphasizing consequences for daily management of infectious disease patients.

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.

Correia Repeat Enclosed Elements and Non-Coding RNAs in the Neisseria Species

Neisseria gonorrhoeae is capable of causing gonorrhoea and more complex diseases in the human host. Neisseria meningitidis is a closely related pathogen that shares many of the same genomic features and virulence factors, but causes the life threatening diseases meningococcal meningitis and septicaemia. The importance of non-coding RNAs in gene regulation has become increasingly evident having been demonstrated to be involved in regulons responsible for iron acquisition, antigenic variation, and virulence. Neisseria spp. contain an IS-like element, the Correia Repeat Enclosed Element, which has been predicted to be mobile within the genomes or to have been in the past. This repeat, present in over 100 copies in the genome, has the ability to alter gene expression and regulation in several ways. We reveal here that Correia Repeat Enclosed Elements tend to be near non-coding RNAs in the Neisseria spp., especially N. gonorrhoeae. These results suggest that Correia Repeat Enclosed Elements may have disrupted ancestral regulatory networks not just through their influence on regulatory proteins but also for non-coding RNAs.

Meningococcal pneumonia

Neisseria meningitidis remains the most important cause of bacterial meningitis worldwide, particularly in children and young adults. The second most common and a potentially severe end-organ manifestation of invasive meningococcal disease (excluding systemic sepsis) is meningococcal pneumonia. It occurs in between 5% and 15% of all patients with invasive meningococcal disease and is thus the second most common non-systemic end-organ manifestation. To establish the diagnosis requires a high level of clinical awareness - the incidence is therefore very likely underreported and underestimated. This review of 344 meningococcal pneumonia cases reported in the Americas, Europe, Australia, and Asia between 1906 and 2015 presents risk factors, pathogenesis, clinical manifestations, diagnostic approaches, treatment, and prognosis of meningococcal pneumonia.