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Introduction Invasive meningococcal disease (IMD) caused by serogroup W meningococci belonging to the ST-11 complex (MenW:cc11) has been increasing globally since the early 2000s. Penicillin resistance among meningococci due to the production of beta-lactamase remains relatively rare. Isolates displaying resistance and reduced susceptibility to penicillin due to alterations in the penA gene (encoding Penicillin Binding Protein 2) are increasingly reported. In 2016, a penicillin-resistant clade of MenW:cc11 isolates with altered penA genes was identified in Australia. More recently, an increase in penicillin-resistant invasive MenW:cc11 isolates was observed in England. Here, we investigate the distribution of penicillin resistance among English invasive MenW:cc11 isolates. Methods Isolates from IMD cases in England from July 2010 to August 2019 underwent whole genome sequencing and antibiotic susceptibility testing as part of routine surveillance. The PubMLST Neisseria database was used to determine the distribution of penicillin resistance among English MenW:cc11 isolates and to identify other closely related isolates. Results Twenty-five out of 897 English invasive MenW:cc11 isolates were resistant to penicillin; identified among six distinct sublineages and a singleton. Expansion of the Australian penicillin-resistant clade included isolates from several new countries as well as 20 English isolates. A newly identified penicillin resistance-associated lineage was also identified among several countries. Conclusion Penicillin resistance among diverse MenW:cc11 isolates is increasing. Surveillance of antibiotic resistance among meningococci is essential to ensure continued effective use.

Summary Background Invasive meningococcal disease (IMD) typically presents as meningitis, septicaemia or both. Atypical clinical presentations are rare but well-described. We aimed to assess the relationship between meningococcal capsular group, age, clinical presentation, diagnosis and outcome among IMD cases diagnosed in England during 2014. Methods Public Health England conducts enhanced national surveillance of IMD in England. Clinical data for laboratory-confirmed MenB, MenW and MenY cases in ≥5 year-olds were used to classify presenting symptoms, diagnosis and outcomes. Multivariable logistic regression was used to assess independent associations between meningococcal capsular group, clinical presentation, gender, age and death. Results In 2014, there were 340 laboratory-confirmed IMD cases caused by MenB (n = 179), MenW (n = 95) and MenY (n = 66). Clinical presentation with meningitis alone was more prevalent among MenB cases (28%) and among 15–24 year-olds (20%), whilst bacteraemic pneumonia was most prevalent among MenY cases (26%) and among ≥65 year-olds (24%). Gastrointestinal symptoms were recorded preceding or during presentation in 15% (40/269) cases with available information, including 5% (7/140) MenB, 17% (8/47) MenY and 30% (25/82) MenW cases. Upper respiratory tract symptoms were reported in 16% (22/141) MenB, 23% (11/47) MenY and 31% (26/84) MenW cases. Increasing age was also independently associated with bacteraemic meningococcal pneumonia, with no cases among 5–14 year-olds compared to 24% in ≥65 year-olds. Case fatality rates increased with age but no significant associations with death were identified. Conclusions Healthcare professionals should be aware of the atypical clinical presentations associated with the less prevalent meningococcal capsular groups in different age-groups.

Between April 2016 and September 2017, four cases of group B meningococcal disease were reported among sixth-form college students in Bristol, UK. Culture and non-culture whole genome sequencing was utilised and demonstrated that the four genomes of the responsible ST-41 strains clustered closely on a sub-lineage of ST-41/44 clonal complex. The outbreak resulted in two fatalities. A distinct social group associated with one of the cases was selected for vaccination with 4CMenB and pharyngeal swabbing. In vitro culturing, multiple real-time PCR assays (sodC, ctrA and siaDB) and a PorA PCR-sequencing assay were used to detect meningococcal colonisation and a carriage rate of 32.6% was observed. Furthermore, a high proportion of the pharyngeal swabs (78.3%) yielded a Factor H-Binding Protein (fHbp) nucleotide allele suggesting that the antigenic gene is prevalent among non-meningococcal flora, most likely Neisseria commensals. This may have implications for fHbp as a vaccine antigen should it be shown to influence bacterial colonisation.

Many bacterial carriage studies utilize colistin-containing media to select for Neisseria meningitidis among the diverse human pharyngeal milieu. These studies commonly report the isolation of Neisseria commensal species, with carriage rates of around 1% or less typically observed. Here, we describe the isolation of N. cinerea and N. polysaccharea from pharyngeal swabs using nonselective agar and confirm they are unable to grow on colistin-containing media. We also demonstrated colistin sensitivity among archived Neisseria commensal strains, including N. cinerea, N. polysaccharea, N. mucosa, and N. subflava. The distribution of lptA among these strains indicated that, while the phosphoethanolamine (PEA) transferase encoded by this gene confers colistin resistance, other mechanisms may lead to reduced susceptibility in some lptA-deficient strains. The majority of the N. cinerea and N. polysaccharea isolates expressed medium to very high levels of factor H-binding protein (fHbp), an important meningococcal vaccine antigen. Sequence analysis showed that the commensal fHbp peptide variants were similar in sequence to fHbp variants typically observed among invasive meningococci. Altogether, these results not only suggest that Neisseria commensal strains could be carried at much higher rates than previously reported but also raise questions about the impact of protein-based meningococcal vaccines on these unencapsulated commensals. IMPORTANCE This study highlights the need for further work to accurately determine the pharyngeal carriage prevalence of Neisseria commensal bacteria (e.g., N. cinerea and N. polysaccharea) among the general population. Previous studies have clearly demonstrated the suppressive effect these commensal species can have on meningococcal colonization, and so the carriage prevalence of these species could be an important factor in the spread of meningococci through the population. Furthermore, the surface expression of the meningococcal vaccine antigen factor H-binding protein by many of these commensal strains could have important implications for the use of fHbp-containing vaccines. Carriage of these commensal species may influence the immune response to these vaccines, or conversely, the immune response elicited by vaccination may induce clearance of these potentially important members of the pharyngeal niche.

BackgroundStreptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis are leading causes of invasive diseases including bacteraemic pneumonia and meningitis, and of secondary infections post-viral respiratory disease. They are typically transmitted via respiratory droplets. We investigated rates of invasive disease due to these pathogens during the early phase of the COVID-19 pandemic.MethodsLaboratories in 26 countries across six continents submitted data on cases of invasive disease due to S pneumoniae, H influenzae and N meningitidis from 1 January 2018 to 31 May 2020. Weekly cases in 2020 vs 2018-2019 were compared. Streptococcus agalactiae data were collected from nine laboratories for comparison to a non-respiratory pathogen. The stringency of COVID-19 containment measures was quantified by the Oxford COVID-19 Government Response Tracker. Changes in population movements were assessed by Google COVID-19 Community Mobility Reports. Interrupted time series modelling quantified changes in rates of invasive disease in 2020 relative to when containment measures were imposed.FindingsAll countries experienced a significant, sustained reduction in invasive diseases due to S pneumoniae, H influenzae and N meningitidis, but not S agalactiae, in early 2020, which coincided with the introduction of COVID-19 containment measures in each country. Similar impacts were observed across most countries despite differing stringency in COVID-19 control policies. There was no evidence of a specific effect due to enforced school closures.InterpretationThe introduction of COVID-19 containment policies and public information campaigns likely reduced transmission of these bacterial respiratory pathogens, leading to a significant reduction in life-threatening invasive diseases in many countries worldwide.

IntroductionCapsular group B Neisseria meningitidis (MenB) is the most common cause of invasive meningococcal disease (IMD) in many parts of the world. A MenB vaccine directed against the polysaccharide capsule remains elusive due to poor immunogenicity and safety concerns. The vaccines licensed for the prevention of MenB disease, 4CMenB (Bexsero) and MenB-fHbp (Trumenba), are serogroup B ‘substitute’ vaccines, comprised of subcapsular proteins and are designed to provide protection against most MenB disease-causing strains. In many high-income countries, such as the UK, adolescents are at increased risk of IMD and have the highest rates of meningococcal carriage. Beginning in the late 1990s, immunisation of this age group with the meningococcal group C conjugate vaccine reduced asymptomatic carriage and disrupted transmission of this organism, resulting in lower group C IMD incidence across all age groups. Whether vaccinating teenagers with the novel ‘MenB’ protein-based vaccines will prevent acquisition or reduce duration of carriage and generate herd protection was unknown at the time of vaccine introduction and could not be inferred from the effects of the conjugate vaccines. 4CMenB and MenB-fHbp may also impact on non-MenB disease-causing capsular groups as well as commensal Neisseria spp. This study will evaluate the impact of vaccination with 4CMenB or MenB-fHbp on oropharyngeal carriage of pathogenic meningococci in teenagers, and consequently the potential for these vaccines to provide broad community protection against MenB disease.Methods and analysisThe ‘Be on the TEAM’ (Teenagers Against Meningitis) Study is a pragmatic, partially randomised controlled trial of 24 000 students aged 16–19 years in their penultimate year of secondary school across the UK with regional allocation to a 0+6 month schedule of 4CMenB or MenB-fHbp or to a control group. Culture-confirmed oropharyngeal carriage will be assessed at baseline and at 12 months, following which the control group will be eligible for 4CMenB vaccination. The primary outcome is the carriage prevalence of potentially pathogenic meningococci (defined as those with genogroups B, C, W, Y or X), in each vaccine group compared separately to the control group at 12 months post-enrolment, that is, 12 months after the first vaccine dose and 6 months after the second vaccine dose. Secondary outcomes include impact on carriage of: genogroup B meningococci; hyperinvasive meningococci; all meningococci; those meningococci expressing vaccine antigens and; other Neisseria spp. A sample size of 8000 in each arm will provide 80% power to detect a 30% reduction in meningococcal carriage, assuming genogroup B, C, W, Y or X meningococci carriage of 3.43%, a design effect of 1.5, a retention rate of 80% and a significance level of 0.05. Study results will be available in 2021 and will inform the UK and international immunisation policy and future vaccine development.Ethics and disseminationThis study is approved by the National Health Service South Central Research Ethics Committee (18/SC/0055); the UK Health Research Authority (IRAS ID 239091) and the UK Medicines and Healthcare products Regulatory Agency. Publications arising from this study will be submitted to peer-reviewed journals. Study results will be disseminated in public forums, online, presented at local and international conferences and made available to the participating schools.Trial registration numbersISRCTN75858406; Pre-results, EudraCT 2017-004609-42.

Since 2015 in the United States (US), the US Neisseria meningitidis urethritis clade (US_NmUC) has caused a large multistate outbreak of urethritis among heterosexual males. Its ‘parent’ strain caused numerous outbreaks of invasive meningococcal disease among men who have sex with men in Europe and North America. We highlight the arrival and dissemination of US_NmUC in the United Kingdom and the emergence of multiple antibiotic resistance. Surveillance systems should be developed that include anogenital meningococci.

Summary The meningococcal ST-11 complex (cc11) causes large invasive disease outbreaks with high case fatality rates, such as serogroup C (MenC) epidemics in industrialised nations in the 1990s and the serogroup W epidemic currently expanding globally. Glycoconjugate vaccines are available for serogroups A, C, W and Y. Broad coverage protein-based vaccines have recently been licensed against serogroup B meningococci (MenB), however, these do not afford universal MenB protection. Capsular switching from MenC to MenB among cc11 organisms is concerning because a large MenB cc11 (B:cc11) outbreak has the potential to cause significant morbidity and mortality. This study aimed to assess the potential for licensed and developmental non-capsular meningococcal vaccines to protect against B:cc11. The population structure and vaccine antigen distribution was determined for a panel of >800 geo-temporally diverse, predominantly MenC cc11 and B:cc11 genomes. The two licensed vaccines potentially protect against many but not all B:cc11 meningococci. Furthermore, strain coverage by these vaccines is often due to a single vaccine antigen and both vaccines are highly susceptible to vaccine escape owing to the apparent dispensability of key proteins used as vaccine antigens. cc11 strains with MenB and MenC capsules warrant special consideration when formulating future non-capsular meningococcal vaccines., Highlights • The meningococcal ST-11 complex (cc11) is highly virulent and has caused large serogroup C and W outbreaks. • Serogroup C to B capsular switching is concerning owing to a lack of a universal vaccine against serogroup B meningococci. • Diverse serogroup B and C cc11 meningococci are predicted not to be covered by non-capsular vaccines targeting MenB. • Dispensability of multiple antigens raises the prospect of vaccine-escape by potentially covered outbreak strains. • Serogroup B and C cc11 meningococci merit special consideration when formulating future non-capsular meningococcal vaccines.

Summary Background Neisseria meningitidis is a major cause of bacterial meningitis and septicaemia, with death often occurring rapidly after onset of the first symptoms. Later death can also occur, but may be due to other causes, such as underlying comorbidities. The study aimed to assess the timing and cause of death in patients with invasive meningococcal disease (IMD) prior to the introduction of two new meningococcal immunisation programmes in England. Methods Public Health England (PHE) conducts IMD surveillance in England through its national meningococcal reference unit. Laboratory-confirmed IMD cases diagnosed during 2008–2015 were linked to weekly and annual electronic death registration records as well as the Patient Demographic Service (PDS) database. Results Overall, 6734 of 6808 (99%) laboratory-confirmed IMD cases matched to PDS, including 668 fatalities. Of these, 667 linked to an annual death registration record compared to 405 reports linked to weekly death registrations. In total, 429/667 (64%) of all deaths and 428/502 (85%) of IMD-related deaths occurred within one day of diagnosis. In total, 498/667 (75%) deaths had occured by 30 days after IMD diagnosis and 98% (490/498) of these were IMD-related. Serogroup B contributed to 64% (323/502) of IMD-related deaths, followed by serogroup W (84/502, 17%) and serogroup Y (70/502, 14%). Deaths occurring after 30 days were less likely to be IMD-related, mainly amongst ≥65 year-olds, with malignancy, chronic respiratory and cardiac conditions predominating. Conclusions Most IMD-related deaths occurred within a day of diagnosis and nearly all IMD-related deaths occurred within 30 days of diagnosis. The rapidity of death highlights the importance of prevention through vaccination.

In 2015, a suspected cluster of two invasive meningococcal disease (IMD) cases of serogroup W Neisseria meningitidis (MenW) occurred in elderly care home residents in England over 7 months; case investigations followed United Kingdom guidance. An incident control team reviewed epidemiological information. Phenotyping of case specimens informed public health action, including vaccination and throat swabs to assess carriage. Whole genome sequencing (WGS) was conducted on case and carrier isolates. Conventional phenotyping did not exclude a microbiological link between cases (case 1 W:2a:P1.5,2 and case 2 W:2a:NT). After the second case, 33/40 residents and 13/32 staff were vaccinated and 19/40 residents and 13/32 staff submitted throat swabs. Two MenW carriers and two MenC carriers were detected. WGS showed that MenW case and carrier isolates were closely related and possibly constituted a locally circulating strain. Meningococcal carriage, transmission dynamics and influence of care settings on IMD in older adults are poorly understood. WGS analyses performed following public health action helped to confirm the close relatedness of the case and circulating isolates despite phenotypic differences and supported actions taken. WGS was not sufficiently timely to guide public health practice.

Background To describe patients with inherited and acquired complement deficiency who developed invasive meningococcal disease (IMD) in England over the last decade. Methods Public Health England conducts enhanced surveillance of IMD in England. We retrospectively identified patients with complement deficiency who developed IMD in England during 2008–2017 and retrieved information on their clinical presentation, vaccination status, medication history, recurrence of infection and outcomes, as well as characteristics of the infecting meningococcal strain. Results A total of 16 patients with 20 IMD episodes were identified, including four with two episodes. Six patients had inherited complement deficiencies, two had immune-mediated conditions associated with complement deficiency (glomerulonephritis and vasculitis), and eight others were on Eculizumab therapy, five for paroxysmal nocturnal haemoglobinuria and three for atypical haemolytic uraemic syndrome. Cultures were available for 7 of 11 episodes among those with inherited complement deficiencies/immune-mediated conditions and the predominant capsular group was Y (7/11), followed by B (3/11) and non-groupable (1/11) strains. Among patients receiving Eculizumab therapy, 3 of the 9 episodes were due to group B (3/9), three others were NG but genotypically group B, and one case each of groups E, W and Y. Conclusions In England, complement deficiency is rare among IMD cases and includes inherited disorders of the late complement pathway, immune-mediated disorders associated with low complement levels and patients on Eculizumab therapy. IMD due to capsular group Y predominates in patient with inherited complement deficiency, whilst those on Eculizumab therapy develop IMD due to more diverse capsular groups including non-encapsulated strains.

Background The total incidence of invasive meningococcal disease (IMD) in Europe has been declining in recent years; however, a rising incidence due to serogroup W (MenW), predominantly sequence type 11 (ST-11), clonal complex 11 (cc11), was reported in some European countries. Aim The aim of this study was to compile the most recent laboratory surveillance data on MenW IMD from several European countries to assess recent trends in Europe. Methods In this observational, retrospective study, IMD surveillance data collected from 2013–17 by national reference laboratories and surveillance units from 13 European countries were analysed using descriptive statistics. Results The overall incidence of IMD has been stable during the study period. Incidence of MenW IMD per 100,000 population (2013: 0.03; 2014: 0.05; 2015: 0.08; 2016: 0.11; 2017: 0.11) and the proportion of this serogroup among all invasive cases (2013: 5% (116/2,216); 2014: 9% (161/1,761); 2015: 13% (271/2,074); 2016: 17% (388/2,222); 2017: 19% (393/2,112)) continuously increased. The most affected countries were England, the Netherlands, Switzerland and Sweden. MenW was more frequent in older age groups (≥ 45 years), while the proportion in children ( Conclusion During the years 2013–17, an increase in MenW IMD, mainly caused by MenW cc11, was observed in the majority of European countries. Given the unpredictable nature of meningococcal spread and the epidemiological potential of cc11, European countries may consider preventive strategies adapted to their contexts.

Since 1996 the Meningococcal Reference Unit (MRU) in Manchester has provided a national service for PCR confirmation of meningococcal and pneumococcal disease. Neisseria meningitidis serogroup B is predominant in the UK, accounting for >60 % of cases. In response to this, the MRU has developed a quadruplex quantitative PCR that detects N. meningitidis capsule transporter (ctrA), serogroup B sialyltransferase (siaD B ), Streptococcus pneumoniae pneumolysin (ply) and an internal control. The assay was prepared in a ready-to-use lyophilized format by Applied Biosystems. Laboratory validation showed excellent performance in a specificity panel of 52 isolates and improved detection in comparison with the routine assay. Testing of 244 patient samples showed sensitivity of 93 % [95 % confidence interval (CI): 88–98 %] for the ctrA assay, 95 % (95 % CI: 91–100 %) for the siaD B assay and 100 % (95 % CI: 95–100 %) for the ply assay. Specificity was 100 % (95 % CI: 98–100 %) for both meningococcal targets and 95 % (95 % CI: 92–98 %) for ply. The quadruplex also retained high performance in mixed samples and had acceptable reproducibility. After introduction of the quadruplex into routine use the turnaround time for N. meningitidis group B PCR confirmation reduced from 37 to 29 h and the internal control has proved useful for detecting inhibitory samples. The quadruplex assay provides rapid group B confirmation of meningococcal positive samples, enabling timely public health interventions for the most common disease-causing meningococcal serogroup in the UK.

Background Deprivation is associated with an increased risk of invasive Neisseria meningitidis disease, but little is known about the relationship between deprivation and asymptomatic carriage of N. meningitidis. This analysis was conducted to examine the relationship between meningococcal carriage and deprivation. Methods As part of a rapid meningococcal carriage prevalence study conducted in West Cumbria to investigate an apparent cluster of invasive meningococcal disease, data were collected on lifestyle and social factors, including area-level indicators of socioeconomic status, to identify factors associated with meningococcal carriage. Results In a multivariable log binomial regression model adjusted for age, lower socioeconomic status was significantly associated with higher prevalence of meningococcal carriage. A 1-unit increase in Index of Multiple Deprivation (2010) score was associated with a 1.7% increase in meningococcal carriage prevalence (95% confidence interval 0.3-3.0%). Age was the only significant predictor of carriage of Neisseria lactamica. Conclusions Living in a deprived area is associated with increased carriage of Group B meningococcus. Deprivation is an important factor to consider in the evaluation of the effectiveness and cost-effectiveness of the introduction of new meningococcal B vaccines and the development and implementation of immunization policies. Further work is required to understand whether deprivation has an effect on meningococcal carriage through other factors such as smoking.

To the Editor: We recently reported that postvaccination serum samples from infants immunized with a novel, protein-based multicomponent meningococcal serogroup B (MenB) vaccine (Bexsero; GlaxoSmithKline Vaccines, Verona, Italy) have bactericidal activity against the hypervirulent meningococcal group W (MenW) strain belonging to the sequence type (ST) 11 clonal complex (1). Historically, MenW has been a rare cause of invasive meningococcal disease (IMD), accounting for

Purpose\ud \ud In August 2015, in response to increasing group W invasive meningococcal disease (IMD) nationally, a MenACWY vaccine programme was introduced in the UK for 13–18 year olds. We reviewed the epidemiology of IMD in young adults and university-associated cases in England during 2014–15 academic year and assessed the potential impact of different immunisation strategies.\ud Methods\ud \ud Public Health England national enhanced surveillance data were used to describe the epidemiology of IMD cases in 15–24 year olds in England during 2014/15. Relative risks for IMD were calculated overall and by capsular group in students compared with non- student peers for 2014 and 2013 school leavers. Assuming stable future incidence and vaccine efficacy of 90% for five years, we estimated cases averted and numbers needed to vaccinate (NNV) for different MenACWY immunisation programmes: school-based adolescent, GP-based school leaver, and targeting freshers.\ud Results\ud \ud Between July 2014 and June 2015, 112 IMD cases were diagnosed in those born between 01/09/1991 and 31/08/2001 (∼15 to 24 year-olds). During the 2014/15 academic year (September to June), 49 IMD cases were reported among students attending English universities, including 22 among 2014 school leavers. In this cohort, the relative risk of IMD was higher among students compared to non-students for all capsular groups (RR 11.6; 95% CI 4.7–28.7) and for groups A/C/W/Y (RR 14.8; 95% CI, 4.3–51.5). A school-based programme could potentially have averted 14 cases in 2014/15 and 24 cases over five years with a lower NNV (18,000) than other programmes.\ud Conclusions\ud \ud University students, particularly first years entering direct from school, are at higher risk for IMD than non-students. With high vaccine coverage and timely completion, an adolescent school-based MenACWY programme has the greatest potential to prevent cases with the lowest NNV, but population impact through indirect (herd) protection could take longer.

In England and Wales, meningococcal disease caused by group W has historically been associated with outbreaks of disease among travellers to high-risk countries. Following a large outbreak associated with travel to the Hajj in 2000, the number of cases declined and, in 2008, only 19 laboratory-confirmed cases were identified nationally. In 2013, in the East Midlands region of England, eight cases of meningococcal disease caused by this serogroup were recorded, compared with six from 2011 to 2012. To explore this further, data for all cases with a date of onset between 1 January 2011 and 31 December 2013 were collected. Data collected included geographical location, clinical presentation and outcome. Fourteen cases were identified; two died as a result of their illness and two developed long-term health problems. No commonality in terms of geographical location, shared space or activities was identified, suggesting that group W is circulating endemically with local transmission. Clinical presentation was variable. Half presented with symptoms not typical of a classical meningococcal disease, including two cases of cellulitis, which may have implications for clinicians, in terms of timely identification and treatment, and public health specialists, for offering timely antibiotic chemoprophylaxis to close contacts.

The 23rd World Scout Jamboree in 2015 took place in Japan and included over 33,000 scouts from 162 countries. Within nine days of the meeting ending, six cases of laboratory-confirmed invasive serogroup W meningococcal disease occurred among scouts and their close contacts in Scotland and Sweden. The isolates responsible were identical to one-another by routine typing and, where known (4 isolates), belonged to the ST-11 clonal complex (cc11) which is associated with large outbreaks and high case fatality rates. Recent studies have demonstrated the need for high-resolution genomic typing schemes to assign serogroup W cc11 isolates to several distinct strains circulating globally over the past two decades. Here we used such schemes to confirm that the Jamboree-associated cases constituted a genuine outbreak and that this was due to a novel and rapidly expanding strain descended from the strain that has recently expanded in South America and the United Kingdom. We also identify the genetic differences that define the novel strain including four point mutations and three putative recombination events involving the horizontal exchange of 17, six and two genes, respectively. Noteworthy outcomes of these changes were antigenic shifts and the disruption of a transcriptional regulator.

Background. In England and Wales, the incidence of invasive meningococcal disease has been declining formore than a decade, but meningococcal group W (MenW) cases have been increasing since 2009.Methods. PublicHealthEnglandconductsenhancednationalsurveillanceofinvasivemeningococcaldiseaseinEn-glandandWales.Detailedclinicalinformationwasobtainedforalllaboratory-confirmedMenWcasesdiagnosedduring3 epidemiologic years (2010–2011 to 2012–2013), alongside whole-genome sequencing analysis of the clinical isolates.Results. Theyear-on-yearincreaseininvasiveMenWdiseaseacrossallagegroupssince2009 –2010wasduetorapidendemic expansion of a single clone belonging to the sequence type 11 complex (cc11). In 2013–2014, MenW wasresponsible for 15% of all invasive meningococcal disease. All but 1 of the recent MenW:cc11 isolates were very closelyrelated, consistent with recent clonal expansion. Clinical follow-up of all 129 MenW cases diagnosed during 2010 –2011to 2012–2013 revealed that most patients were previously healthy (n=105 [81%]), had not travelled abroad prior toillness and the majority presented with septicemia (n=63 [49%]), meningitis (n=16 [12%]) or both (n=21 [16%]);however, one-quarter had atypical presentations including pneumonia (n=15 [12%]), septic arthritis (n=9 [7%]),and epiglottitis/supraglottitis (n=5 [4%]). Forty-eight (37%) required intensive care and 15 (12%) died. There wasno association between infecting strain, clinical disease, or outcome.Conclusions . The recent increase in invasive MenW disease in England and Wales is due to rapid endemic expan-sion of a single clone belonging to cc11 and is associated with severe disease with unusual clinical presentations. Thisincrease will require careful monitoring in the coming years.Keywords. meningococcal W disease; meningococcal pneumonia; ST-11 clonal complex; travel; epidemiology.Neisseria meningitidisis a major infectious cause ofmorbidity and mortality worldwide [1]. In the UnitedKingdom, routine vaccination against meningococcalcapsular group C (MenC) since 1999 has resulted incapsular group B (MenB) being responsible for >85%of invasive meningococcal disease (IMD) cases acrossall age groups [2]. The meningococcal quadrivalentconjugate vaccine (MenACWY) is only used for high-risk individuals and travelers to endemic regions andfor controlling outbreaks. Recently, much attentionhas been focused on MenB prevention following thelicensure of a novel, protein-based, multicomponentvaccineinEurope[3].Atpresent,however,EnglandandWales are experiencing an upsurge in invasive capsulargroupW(MenW)disease.Historically,MenWincidencehas been low, accounting for only 1%–2% of IMD casesannually. An increase during 2000–2002 was associatedwith travel to the Hajj [4], but following mandatorymeningococcal vaccination for pilgrims, MenW cases

Molecular PorA subtyping provides information that increasingly requires the adaptation of standard public health approaches to outbreak management. We report an outbreak of a rare subtype of meningococcal infection not previously identified in the United Kingdom (UK). The outbreak occurred in the Warwickshire area in England between February and June 2013. Molecular subtyping allowed the identification of additional cases, prompting an enhanced public health response that included efforts to identify potential social networks that might benefit from chemoprophylaxis. It also prompted swabbing to define nasopharyngeal carriage in the focal nursery and helped explain the unusual epidemiological pattern. Without subtyping to identify a link, the additional cases would have been managed as sporadic cases in accordance with current UK guidance.

Summary Background Meningococcal conjugate vaccines protect individuals directly, but can also confer herd protection by interrupting carriage transmission. We assessed the effects of meningococcal quadrivalent glycoconjugate (MenACWY-CRM) or serogroup B (4CMenB) vaccination on meningococcal carriage rates in 18–24-year-olds. Methods In this phase 3, observer-blind, randomised controlled trial, university students aged 18–24 years from ten sites in England were randomly assigned (1:1:1, block size of three) to receive two doses 1 month apart of Japanese Encephalitis vaccine (controls), 4CMenB, or one dose of MenACWY-CRM then placebo. Participants were randomised with a validated computer-generated random allocation list. Participants and outcome-assessors were masked to the treatment group. Meningococci were isolated from oropharyngeal swabs collected before vaccination and at five scheduled intervals over 1 year. Primary outcomes were cross-sectional carriage 1 month after each vaccine course. Secondary outcomes included comparisons of carriage at any timepoint after primary analysis until study termination. Reactogenicity and adverse events were monitored throughout the study. Analysis was done on the modified intention-to-treat population, which included all enrolled participants who received a study vaccination and provided at least one assessable swab after baseline. This trial is registered with ClinicalTrials.gov, registration number NCT01214850. Findings Between Sept 21 and Dec 21, 2010, 2954 participants were randomly assigned (987 assigned to control [984 analysed], 979 assigned to 4CMenB [974 analysed], 988 assigned to MenACWY-CRM [983 analysed]); 33% of the 4CMenB group, 34% of the MenACWY-CRM group, and 31% of the control group were positive for meningococcal carriage at study entry. By 1 month, there was no significant difference in carriage between controls and 4CMenB (odds ratio 1·2, 95% CI 0·8–1·7) or MenACWY-CRM (0·9, [0·6–1·3]) groups. From 3 months after dose two, 4CMenB vaccination resulted in significantly lower carriage of any meningococcal strain (18·2% [95% CI 3·4–30·8] carriage reduction), capsular groups BCWY (26·6% [10·5–39·9] carriage reduction), capsular groups CWY (29·6% [8·1–46·0] carriage reduction), and serogroups CWY (28·5% [2·8–47·5] carriage reduction) compared with control vaccination. Significantly lower carriage rates were also noted in the MenACWY-CRM group compared with controls: 39·0% (95% CI 17·3–55·0) carriage reduction for serogroup Y and 36·2% (15·6–51·7) carriage reduction for serogroup CWY. Study vaccines were generally well tolerated, with increased rates of transient local injection pain and myalgia in the 4CMenB group. No safety concerns were identified. Interpretation Although we detected no significant difference between groups at 1 month after vaccine course, MenACWY-CRM and 4CMenB vaccines reduced meningococcal carriage rates during 12 months after vaccination and therefore might affect transmission when widely implemented. Funding Novartis Vaccines.

Objectives : To describe the epidemiological, clinical and laboratory features of meningococcal meningitis and the effects of antibiotics on laboratory investigations under current clinical practices in England and Wales. Methods: Using a telephone questionnaire, information was gathered on 103 cases with a clinical diagnosis of meningococcal meningitis. Included were cases with samples submitted to the Public Health Laboratory Service (PHLS), Meningococcal Reference Unit (MRU) over a 5-month period in 1997. Tests included microscopic examination, latex agglutination and culture for Neisseria meningitidis, and at MRU confirmation of identification and characterization of isolates and meningococal polymerase chain reaction (PCR) analysis on blood and cerebrospinal fluids (CSF). Results : Clinically 45% of the cases had predominantly meningitis and 55% had septicaemia and meningitis. Only 29% of the cases received pre-admission benzylpenicillin, and 66% were given antibiotics within an hour of hospital attendance. Microbiological confirmation was achieved in 97 cases, 46 (44%) by traditional tests and 92 (89%) by PCR assay, including some with both. The blood culture positive rate was 23 (22%), but in predominant meningitis the rate was only 10% (5/46). PCR was the sole method of confirmation in 48 cases. Seventy percent of the plasma samples referred were reactive by PCR assay, but all samples taken more than 24 h after hospital antibiotics were non-reactive. PCR-based techniques increased the overall number of cases with a serogroup identified by 44%. Lumbar punctures were performed in 73 of the cases and microbiological confirmation was achieved in 67 (92%) of these cases, compared to 26/30 without lumbar puncture (LP). Eighty-nine percent of the CSF samples referred were reactive by PCR; 50% of the CSF samples taken more than 24 h after hospital antibiotics were reactive, whilst none were positive by culture or microscopy. Conclusion : Due to variable clinical manifestations, early diagnosis and treatment was difficult. Laboratory confirmation has been improved by the introduction of PCR-based techniques. Meningococcal DNA was detected by molecular methods in CSF samples taken up to 72 h after commencement of antibiotics. During this period patients could be stabilized and the chances of complications attendant upon early LP reduced. In addition to providing accurate epidemiological information, confirming the diagnosis may alter the extent and length of follow-up.

Periodically, new disease-associated variants of the human pathogen Neisseria meningitidis arise. These meningococci diversify during spread, and related isolates recovered from different parts of the world have different genetic and antigenic characteristics. An example is the ET-5 complex, members of which were isolated globally from the mid-1970s onwards. Isolates from a hyperendemic outbreak of meningococcal disease in Worcester, England, during the late 1980s were characterized by multilocus sequence typing and sequence determination of antigen genes. These data established that the Worcester outbreak was caused by ET-5 complex meningococci which were not closely related to the ET-5 complex bacteria responsible for a hyperendemic outbreak in the nearby town of Stroud during the years preceding the Worcester outbreak. A comparison with other ET-5 complex meningococci established that there were at least three distinct globally distributed subpopulations within the ET-5 complex, characterized by particular housekeeping and antigen gene alleles. The Worcester isolates belonged to one of these subpopulations, the Stroud isolates belonged to another, and at least one representative of the third subpopulation identified in this work was isolated elsewhere in the United Kingdom. The sequence data demonstrated that ET-5 variants have arisen by multiple complex pathways involving the recombination of antigen and housekeeping genes and de novo mutation of antigen genes. The data further suggest that either the ET-5 complex has been in existence for many years, evolving and spreading relatively slowly until its disease-causing potential was recognized, or it has evolved and spread rapidly since its first identification in the 1970s, with each of the subpopulations attaining a distribution spanning several continents.

Transmission of Neisseria meningitidis mainly occurs by formation of aerosols generated in the nasopharynx. Working with meningococci in vitro and performing manipulations where aerosols may be generated may result in laboratory acquired infections if appropriate safety precautions are not taken. This review details the practical aspects and experience of safe working with N. meningitidis in the laboratory. The specific risk factor for laboratory-acquired infection is exposure to aerosols containing meningococci. Prevention should therefore focus on the use of microbiology safety cabinets during manipulation of meningococci and this should be reflected in local risk assessments, supported by safe practices of work appropriate facilities and equipment, training/competency and immunisation policies.

Summary Objectives In England, national guidance recommends that all patients with suspected invasive meningococcal disease (IMD) should be investigated by blood culture and polymerase chain reaction (PCR) testing. The Meningococcal Reference Unit (MRU) provides a national service for meningococcal species confirmation and PCR-testing of clinical samples. We performed a population-level assessment of the added value of PCR-testing for IMD to augment traditional culture confirmation. Methods We analysed all PCR-samples and invasive meningococcal isolates received by MRU in 2009 and 2010. We assumed that all patients with PCR-samples submitted to MRU also had blood cultures performed and that positive blood cultures were referred to MRU. We confirmed this assertion by case ascertainment. Results In total, 25,379 specimens from 22,039 patients were submitted for PCR-testing and 1492 (6.8%) tested PCR-positive. MRU received 825 invasive meningococcal isolates; 393 confirmed by PCR and culture, 405 without a PCR-specimen submitted and 27 with a PCR-negative result. Thus, of 1924 reported IMD cases, 1099 (57.1%) were confirmed by PCR only, 432 (22.5%) by culture only and 393 (20.4%) by both tests. Conclusion More than half of all confirmed IMD cases were confirmed by PCR only, indicating this service ensures high case ascertainment for national surveillance.

A cluster of four confirmed cases of meningococcal disease was seen in the same nuclear family across a 15-week period. The cases were three siblings and a parent and all recovered well. The first case was confirmed by meningococcal PCR only but the subsequent three cases were due to indistinguishable strains of serogroup B (B:NT:P1.19-1,15-11). Contact tracing was initially undertaken and reviewed in detail after each subsequent case. Antibiotic prophylaxis was administered to close family contacts on three separate occasions, including switching of antibiotic agents, with good compliance. Subsequent investigation of the family has not revealed any obvious immunological problem and no further significant infections have been recognised. A cluster of meningococcal disease of this nature and timescale is highly unusual. Details of the cluster, investigation and implications for health protection practice are discussed.

A cluster of three fatal cases of invasive meningococcal disease due to Neisseria meningitidis serogroup B in a town in Suffolk, United Kingdom, during December 2009 to January 2010 was reported to the local Health Protection Unit. This paper describes the investigation undertaken to identify any potential epidemiological links among the cases, to determine if this was an outbreak and to consider whether to implement community-wide interventions and control measures. Case epidemiological information in addition to serogroup and genosubtyping (porA gene sequencing) data of the infecting organism was gathered on all cases in this reported cluster. Genosubtyping was also retrospectively requested for all serogroup B cases confirmed in Suffolk during 2009. Extensive investigation failed to establish an epidemiological link among the cluster of fatal cases of serogroup B invasive meningococcal disease in Suffolk. By demonstrating a number of distinct strains, the genosubtyping of isolates proved to be useful in the public health management of this incident by serving to exclude a community outbreak and preventing unnecessary mass chemoprophylaxis.

International audience; The distribution of the haemoglobin receptor gene (hmbR) was investigated in disease and carried Neisseria meningitidis isolates revealing that the gene occurred at a significantly higher frequency in disease isolates compared to those obtained from carriage. Where hmbR was absent, the locus was occupied by the cassettes exl2 or exl3, or with a "pseudo hmbR" gene designated exl4. The hmbR locus in published N. meningitidis genomes, as well as N. gonorrhoeae and N. lactamica ST-640, exhibited characteristics of a pathogenicity island. These data are consistent with a role for the hmbR gene in meningococcal disease.

Summary. A restriction fragment length polymorphism (RFLP) typing method was developed for Neisseria meningitidis. A cloned EcoRI fragment from a Neisseria meningitidis Group B serotype 15P1.16 sulphonamide-resistant strain was used to probe Southern blots of total chromosomal DNA restriction fragments (enzyme Aval). A group of 75 apparently unrelated organisms gave rise to 26 different restriction fragment length patterns and two different groups of epidemiologically related strains had RFLP patterns that were distinct for each group. The technique was highly reproducible and discriminatory. The RFLP data were compared with the results of serotyping and subtyping and isoenzyme electrophoretotyping. The RFLP data were consistent with those from the alternative typing methods; clones defined by isoenzyme analysis were subdivided by this technique. The use of RFLP typing by cloned probes should be of considerable epidemiological value.

Vaccines to prevent bacterial meningitis in this region must provide reliable protection against serogroup W-135., Determination of the etiology of bacterial meningitis and estimating cost of disease are important in guiding vaccination policies. To determine the incidence and etiology of meningitis in Turkey, cerebrospinal fluid (CSF) samples were obtained prospectively from children (1 month–17 years of age) with a clinical diagnosis of acute bacterial meningitis. Multiplex PCR was used to detect DNA evidence of Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis. In total, 408 CSF samples were collected, and bacterial etiology was determined in 243 cases; N. meningitidis was detected in 56.5%, S. pneumoniae in 22.5%, and Hib in 20.5% of the PCR-positive samples. Among N. meningitidis–positive CSF samples, 42.7%, 31.1%, 2.2%, and 0.7% belonged to serogroups W-135, B, Y, and A, respectively. This study highlights the emergence of serogroup W-135 disease in Turkey and concludes that vaccines to prevent meningococcal disease in this region must provide reliable protection against this serogroup.

Serogroup-specific antibody has been shown to be present in the sera of patients recovering from meningococcal disease, and thus the detection of such antibodies may aid in the confirmation of disease. There are currently no standard methods for measuring meningococcal serogroup B-specific antibody in sera. Here, we report the development of a microsphere-based immunoassay which utilizes colominic acid from Escherichia coli 07:K1 (L):NM to detect immunoglobulin M directed against serogroup B polysaccharide. The serogroup B assay was incorporated into a multiplex assay which also detects serogroup-specific immunoglobulin M for meningococcal serogroups A, C, Y and W-135. Using the method of cross-standardization, serogroup B-specific immunoglobulin M concentrations were assigned to the standard serum CDC 1992. The assay is able to detect increases in specific immunoglobulin M concentrations from acute to convalescent phase serum from serogroup B cases, and can be utilized in conjunction with the previously developed tetraplex immunoglobulin G detection assay for serogroups A, C, Y and W-135.

At a time when tetravalent conjugate vaccines for meningococcal serogroups A/C/Y/W135 are being formulated the O-acetylation status of their respective capsular polysaccharides has not previously been studied in the UK for all components. Although this has been elucidated for serogroup C, little is known about the O-acetylation status of serogroups W135 and Y. Meningococcal serogroup W135 (n=181) and Y (n=90) isolates submitted to the PHLS Meningococcal Reference Unit in 1996, 2000 and 2001 were investigated for O-acetylation capsular status by dot blot assay. Eight per cent of W135 and 79% of Y isolates respectively were found to be O-acetylated with a similar distribution found in both carrier and case isolates. An increase in O-acetylated W135 isolates was noted between 2000 (0%) and 2001 (21%) which was not due to the introduction of the Hajj associated W135 (ET 37 complex; serosubtype P1.5,2) isolates, all of which were de-O-acetylated. Although the biological relevance of O-acetylation status is unknown for these serogroups, an understanding of O-acetylation status of the respective polysaccharides may provide useful insights into the optimal vaccine formulation.

Five probable secondary cases of meningococcal disease were identified in microbiology laboratory workers in England and Wales during a 15-year period. All cases had prepared suspensions of Neisseria meningitidis outside a safety cabinet upto seven days before onset of illness. Relative risk in laboratory workers compared with the background adult population was 184 (95% CI 60–431). In view of the potentially serious outcome from this infection, a safety cabinet should always be used when preparing or working with suspensions of meningococci. Vaccination policy for microbiology laboratory workers should be reviewed.

An outbreak of W135 meningococcal disease occurred in the spring of 2000 among pilgrims returning from Saudi Arabia and their contacts. Clinical isolates from England and France were examined and compared with reference strains from other countries. Characterisation of isolates by a range of typing methods showed them to be of clonal origin (ET-37) and closely related to other meningococci with an established propensity to cause disease clusters. A reappraisal of vaccination strategies for travellers is required.

1Neisseria meningitidis carriage was compared in swab specimens of nasopharynx, tonsils, and saliva taken from 258 students. We found a higher yield in nasopharyngeal than in tonsillar swabs (32% vs. 19%, p

Summary Objectives Neisseria meningitidis is a leading cause of meningitis and septicaemia. The hyperinvasive ST-11 clonal complex (cc11) caused serogroup C (MenC) outbreaks in the US military in the 1960s and UK universities in the 1990s, a global Hajj-associated serogroup W (MenW) outbreak in 2000–2001, and subsequent MenW epidemics in sub-Saharan Africa. More recently, endemic MenW disease has expanded in South Africa, South America and the UK, and MenC cases have been reported among European and North American men who have sex with men (MSM). Routine typing schemes poorly resolve cc11 so we established the population structure at genomic resolution. Methods Representatives of these episodes and other geo-temporally diverse cc11 meningococci (n = 750) were compared across 1546 core genes and visualised on phylogenetic networks. Results MenW isolates were confined to a distal portion of one of two main lineages with MenB and MenC isolates interspersed elsewhere. An expanding South American/UK MenW strain was distinct from the ‘Hajj outbreak’ strain and a closely related endemic South African strain. Recent MenC isolates from MSM in France and the UK were closely related but distinct. Conclusions High resolution ‘genomic’ multilocus sequence typing is necessary to resolve and monitor the spread of diverse cc11 lineages globally., Highlights • The meningococcal ST-11 clonal complex is diverse. • A ‘South American’ serogroup W strain is currently expanding in the UK. • Supports decision to vaccinate UK teenagers against meningococcal serogroup W. • A distinct endemic South African strain is related to the 2000 Hajj outbreak strain. • Serogroup C cases among MSM in UK and France are related but distinct.