Expansion of Neisseria meningitidis Serogroup C Clonal Complex 10217 during Meningitis Outbreak, Burkina Faso, 2019

During January 28-May 5, 2019, a meningitis outbreak caused by Neisseria meningitidis serogroup C (NmC) occurred in Burkina Faso. Demographic and laboratory data for meningitis cases were collected through national case-based surveillance. Cerebrospinal fluid was collected and tested by culture and real-time PCR. Among 301 suspected cases reported in 6 districts, N. meningitidis was the primary pathogen detected; 103 cases were serogroup C and 13 were serogroup X. Whole-genome sequencing revealed that 18 cerebrospinal fluid specimens tested positive for NmC sequence type (ST) 10217 within clonal complex 10217, an ST responsible for large epidemics in Niger and Nigeria. Expansion of NmC ST10217 into Burkina Faso, continued NmC outbreaks in the meningitis belt of Africa since 2019, and ongoing circulation of N. meningitidis serogroup X in the region underscore the urgent need to use multivalent conjugate vaccines in regional mass vaccination campaigns to reduce further spread of those serogroups.

Antimicrobial susceptibility profiles and genotyping of Neisseria meningitidis of serogroup C, Italy, 2000-2020

Background

In Italy the introduction of meningococcal C conjugate vaccine in 2005 has led to a significant reduction of invasive meningococcal disease (IMD) caused by Neisseria meningitidis of serogroup C (MenC). However, this serogroup is still responsible of sporadic cases, clusters and local outbreaks. The study aims to investigate the genotype and antimicrobial susceptibility profile of MenC isolates collected in Italy from 2000 to 2020.

Methods

Bacterial isolates and biological samples (blood or cerebrospinal fluid) from invasive meningococcal cases are collected and characterized at the National Reference Laboratory for IMD of Istituto Superiore di Sanità. Antimicrobial susceptibility was determined by MIC Test Strip Method and interpreted according to the EUCAST breakpoints guideline. Genotypic characteristics, including multi locus sequence typing (MLST), finetype, and antimicrobial resistance target genes were performed and analyzed using the PubMLST database. Genomic comparison of core genome MLST (cgMLST) of MenC genomes was also carried out.

Results

From 2000 to 2020, a total of 665 MenC isolates were investigated for antimicrobial susceptibility and 301 for genotyping. Over two decades, almost all MenC isolates resulted susceptible to antimicrobials with few isolates resulting resistant to ciprofloxacin (N = 2), penicillin G (N = 13), and rifampicin (N = 9), respectively. Molecular typing of MenC obtained from isolates or clinical specimens identified mostly the genotype C:P1.5-1,10-8:F3-6:ST-11(cc11). However, phylogenetic analysis, performed on genomes from MenC isolates, identified two sub lineages, 11.1 and 11.2, among cc11, of which the sub lineage 11.2 was the predominant.

Conclusion

Wider application of the genomic analysis and monitoring of antimicrobial susceptibility represent key aspects of IMD surveillance and to monitor the continued evolution of these hyperinvasive strains.

A New Sequence Type of Neisseria meningitidis Serogroup C Associated With a 2016 Meningitis Outbreak in Mali

In 2016, Mali reported a bacterial meningitis outbreak consisting of 39 suspected cases between epidemiologic weeks 9 and 17 with 15% case fatality ratio in the health district of Ouéléssebougou, 80 kilometers from the capital Bamako. Cerebrospinal fluid specimens from 29 cases were tested by culture and real-time polymerase chain reaction; 22 (76%) were positive for bacterial meningitis pathogens, 16 (73%) of which were Neisseria meningitidis (Nm). Of the Nm-positive specimens, 14 (88%) were N meningitidis serogroup C (NmC), 1 was NmW, and 1 was nongroupable. Eight NmC isolates recovered by culture from the outbreak were characterized using whole genome sequencing. Genomics analysis revealed that all 8 isolates belonged to a new sequence type (ST) 12446 of clonal complex 10217 that formed a distinct clade genetically similar to ST-10217, a NmC strain that recently caused large epidemics of meningitis in Niger and Nigeria. The emergence of a new ST of NmC associated with an outbreak in the African meningitis belt further highlights the need for continued molecular surveillance in the region.

Epidemics of meningococcal meningitis in Northern Nigeria focus on preventive measures

Throughout the past 200 years, epidemics of meningococcal infection have been noted in Northern Nigeria. Consequently, control of meningococcal meningitis is one of the major priorities in infection control in the region. The proportions of cases of invasive meningococcal disease (IMD) caused by the five common serotypes (A, B, C, Y, and W135) vary among different regions and within specific geographic locations. Hence, effective and comprehensive disease control can only be achieved with the use of vaccines that target all of these disease-causing serotypes. Vaccines for the majority of meningococcal serogroups implicated in causing IMD are available in developed countries and have proven effective in reducing the disease incidence. However, the overall success of a vaccine depends on its coverage of the at-risk population as well as safety and effectiveness of the vaccine at preventing disease. Therefore, maximizing the global impact of these vaccines requires having them made available in regions with the high incidence of the disease, like Northern Nigeria, where rates of meningococcal disease are several times higher than in industrialized nations, and the reported mortality is usually high.

Increased incidence of invasive meningococcal disease of serogroup C / clonal complex 11, Tuscany, Italy, 2015 to 2016

We report an increase of serogroup C Neisseria meningitidis invasive meningococcal disease in Tuscany. From January 2015 to end February 2016, 43 cases were reported, among which 10 were fatal, compared to two cases caused by serogroup C recorded in 2014 and three in 2013. No secondary cases occurred. Thirty-five strains belonged to C:P1.5-1,10-8:F3-6:ST-11(cc11). Control measures have been adopted and immunisation campaigns implemented. Studies on risk factors and carriage are ongoing.

Risk Factors for Serogroup C Meningococcal Disease during Outbreak among Men who Have Sex with Men, New York City, New York, USA

Risk factors for illness during a serogroup C meningococcal disease outbreak among men who have sex with men in New York City, New York, USA, in 2012–2013 included methamphetamine and cocaine use and sexually transmitted infections. Outbreak investigations should consider routinely capturing information regarding drug use and sex-related risk factors.

Community-Based Outbreak of Neisseria meningitidis Serogroup C Infection in Men who Have Sex with Men, New York City, New York, USA, 2010-2013

Questions about how to protect this at-risk population deserve careful consideration.

In September 2012, the New York City Department of Health and Mental Hygiene identified an outbreak of Neisseria meningitidis serogroup C invasive meningococcal disease among men who have sex with men (MSM). Twenty-two case-patients and 7 deaths were identified during August 2010−February 2013. During this period, 7 cases in non-MSM were diagnosed. The slow-moving outbreak was linked to the use of websites and mobile phone applications that connect men with male sexual partners, which complicated the epidemiologic investigation and prevention efforts. We describe the outbreak and steps taken to interrupt transmission, including an innovative and wide-ranging outreach campaign that involved direct, internet-based, and media-based communications; free vaccination events; and engagement of community and government partners. We conclude by discussing the challenges of managing an outbreak affecting a discrete community of MSM and the benefits of using social networking technology to reach this at-risk population.

Sequence Type 4821 Clonal Complex Serogroup B Neisseria meningitidis in China, 1978-2013

Serogroup B Neisseria meningitidis strains belonging to sequence type 4821 clonal complex (CC4821), a hyperinvasive lineage first identified for serogroup C in 2003, have been increasingly isolated in China. We characterized the outer membrane protein genes of 48 serogroup B and 214 serogroup C strains belonging to CC4821 and analyzed the genomic sequences of 22 strains. Four serogroup B strains had porin A (i.e., PorA), PorB, and ferric enterobactin transport (i.e., FetA) genotypes identical to those for serogroup C. Phylogenetic analysis of the genomic sequences showed that the 22 CC4821 strains from patients and healthy carriers were unevenly clustered into 2 closely related groups; each group contained serogroup B and C strains. Serogroup B strains appeared variable at the capsule locus, and several recombination events had occurred at uncertain breakpoints. These findings suggest that CC4821 serogroup C N. meningitidis is the probable origin of highly pathogenic CC4821 serogroup B strains.

Is a single infant priming dose of meningococcal serogroup C conjugate vaccine in the United Kingdom sufficient?

In 1999, the UK introduced meningococcal serogroup C conjugate (MCC) vaccination at 2, 3, 4 months of age with a single dose for children 1-18 y In 2006, the schedule was refined to a 2 dose priming schedule with a booster in the second year of life. In 2013, the number of priming doses was reduced to a single priming dose, the booster maintained at 12 months of age and an adolescent booster dose introduced. The paper presents the evidence supporting the reduction in the number of priming doses. A UK study provided evidence for reducing the priming doses of MCC-TT together with the positive correlation of lower quantity of antigen and serum bactericidal antibody (SBA) levels post-primary but a higher magnitude of the booster response. Another UK study, demonstrated one dose of MCC-TT or MCC-CRM197 at 3 months gave comparable responses to 2 doses (SBA titres ≥8) both post-primary vaccination and post-booster Hib/MCC-TT at 12 months. However, the magnitude of the SBA GMT was higher in the MCC-TT primed post-booster. A single priming dose of MCC-TT (at 4 or 6 months) compared to 2 doses (2 and 4 months) gave higher SBA titres in all groups, post-primary and post-booster at 12-13 months, with the highest SBA responses observed in the 4 month single dose group. A study in Malta, comparing one dose of MCC-TT or MCC-CRM197 at (3 months) versus 2 doses of MCC-CRM197 (3 and 4 months), showed a high proportion (>84.72%) of subjects achieving SBA titres ≥8 following a single dose. These studies show that a single-dose priming MCC vaccination in infancy is sufficient.

Carriage rate and effects of vaccination after outbreaks of serogroup C meningococcal disease, Brazil, 2010

Polysaccharide vaccine did not affect carriage nor interrupt transmission of an epidemic strain.

During 2010, outbreaks of serogroup C meningococcal (MenC) disease occurred in 2 oil refineries in São Paulo State, Brazil, leading to mass vaccination of employees at 1 refinery with a meningococcal polysaccharide A/C vaccine. A cross-sectional study was conducted to assess the prevalence of meningococci carriage among workers at both refineries and to investigate the effect of vaccination on and the risk factors for pharyngeal carriage of meningococci. Among the vaccinated and nonvaccinated workers, rates of overall meningococci carriage (21.4% and 21.6%, respectively) and of MenC carriage (6.3% and 4.9%, respectively) were similar. However, a MenC strain belonging to the sequence type103 complex predominated and was responsible for the increased incidence of meningococcal disease in Brazil. A low education level was associated with higher risk of meningococci carriage. Polysaccharide vaccination did not affect carriage or interrupt transmission of the epidemic strain. These findings will help inform future vaccination strategies.

The impact of the meningococcal serogroup C conjugate vaccine in Canada between 2002 and 2012

BACKGROUND

Before 2001, the incidence of invasive meningococcal disease (IMD) in Canada was 1.0 per 100 000 per year, with 40% of cases caused by serogroup C organisms. During 2001-2005 all provinces introduced the meningococcal serogroup C conjugate vaccine (MCCV) into their routine infant immunization schedule.

METHODS

Active, prospective, population-based surveillance of IMD in children and adults was conducted by the Canadian Immunization Monitoring Program, ACTive (IMPACT) during 2002-2012. Inclusion criteria were admission to hospital and identification of Neisseria meningitidis from a sterile site. Incidence was estimated using population census data from Statistics Canada.

RESULTS

Prior to MCCV introduction, serogroup C disease incidence was 0.07-0.25 per 100 000 per year depending on the province. Following vaccine introduction, serogroup C disease decreased to <0.05 per 100 000 per year, with a reduction of 14% per year (P = .0014). A decrease occurred in all provinces, despite differing schedules being implemented. The largest decrease of 83% (from 0.27 to 0.05 per 100 000 per year) occurred in the 15-24 year age group (P = .0100) who were not vaccinated in all provinces. There was no impact on the incidence of nonserogroup C disease over the same period (P = .9811).

CONCLUSIONS

MCCV dramatically reduced the incidence of serogroup C IMD in Canada through both direct and indirect effects. The observation that disease incidence decreased with different schedules suggests that the doses at 12 months (common to all provinces) and adolescence (7 of 8 provinces studied) were critical in achieving disease control.

Three outbreak-causing Neisseria meningitidis serogroup C clones, Brazil(1.)

During 2003–2012, 8 clusters of meningococcal disease were identified in Rio de Janeiro State, Brazil, all caused by serogroup C Neisseria meningitidis. The isolates were assigned to 3 clonal complexes (cc): cc11, cc32, and cc103. These hyperinvasive disease lineages were associated with endemic disease, outbreaks, and high case-fatality rates.

Three outbreak-causing Neisseria meningitidis serogroup C clones, Brazil(1.)

During 2003-2012, 8 clusters of meningococcal disease were identified in Rio de Janeiro State, Brazil, all caused by serogroup C Neisseria meningitidis. The isolates were assigned to 3 clonal complexes (cc): cc11, cc32, and cc103. These hyperinvasive disease lineages were associated with endemic disease, outbreaks, and high case-fatality rates.