Oropharyngeal meningococcal carriage in children and adolescents, a single center study in Buenos Aires, Argentina

[Bartholinitis due to Neisseria meningitidis: Clinical case]

Bartholinitis is the inflammation and infection of the Bartholin's glands that results from the accumulation of mucus in their ducts, the most frequent causal microorganisms being anaerobic and aerobic bacteria and those responsible for sexually transmitted infections. Those caused by agents not belonging to the genital microbiota are less frequent. Likewise, in most cases the diagnosis is clinical. Here, we describe the case of a 42-year-old heterosexual woman with a Bartholin's gland abscess caused by Neisseria meningitidis, isolated through culture and identified by VITEK®2. For molecular characterization and subtyping, the sequence type and clonal complex were determined using the multiple locus sequence typing technique. The antigenic profile was studied by amplification and sequencing of the genes coding for PorA, fHbp, NHBA and NadA and the susceptibility profile was assessed by MIC. Molecular diagnosis led to the confirmation of N. meningitidis as the pathogen responsible for bartholinitis.

Genetic characterization and estimated 4CMenB vaccine strain coverage of 284 Neisseria meningitidis isolates causing invasive meningococcal disease in Argentina in 2010-2014

Meningococcal (Neisseria meningitidis) serogroup B (MenB) strain antigens are diverse and a limited number of strains can be evaluated using the human serum bactericidal antibody (hSBA) assay. The genetic Meningococcal Antigen Typing System (gMATS) was developed to predict the likelihood of coverage for large numbers of isolates by the 4CMenB vaccine, which includes antigens Neisseria adhesin A (NadA), Neisserial Heparin-Binding Antigen (NHBA), factor H-binding protein (fHbp), and Porin A (PorA). In this study, we characterized by whole-genome analyses 284 invasive MenB isolates collected from 2010 to 2014 by the Argentinian National Laboratories Network (52-61 isolates per year). Strain coverage was estimated by gMATS on all isolates and by hSBA assay on 74 randomly selected isolates, representative of the whole panel. The four most common clonal complexes (CCs), accounting for 81.3% of isolates, were CC-865 (75 isolates, 26.4%), CC-32 (59, 20.8%), CC-35 (59, 20.8%), and CC-41/44 (38, 13.4%). Vaccine antigen genotyping showed diversity. The most prevalent variants/peptides were fHbp variant 2, NHBA peptides 24, 21, and 2, and PorA variable region 2 profiles 16-36 and 14. The nadA gene was present in 66 (23.2%) isolates. Estimated strain coverage by hSBA assay showed 78.4% of isolates were killed by pooled adolescent sera, and 51.4% and 64.9% (based on two different thresholds) were killed by pooled infant sera. Estimated coverage by gMATS (61.3%; prediction interval: 55.5%, 66.7%) was consistent with the infant hSBA assay results. Continued genomic surveillance is needed to evaluate the persistence of major MenB CCs in Argentina.

Epidemiology of Meningococcal Disease in Four South American Countries and Rationale of Vaccination in Adolescents from the Region: Position Paper of the Latin American Society of Pediatric Infectious Diseases (SLIPE)

Surveillance of meningococcal disease (MD) is crucial after the implementation of vaccination strategies to monitor their impact on disease burden. Adolescent vaccination could provide direct and indirect protection. Argentina, Brazil, and Chile have introduced meningococcal conjugate vaccines (MCV) into their National Immunization Programs (NIP), while Uruguay has not. Here, we analyze the epidemiology of MD and vaccination experience from these four South American countries to identify needs and plans to improve the current vaccination programs.

METHODOLOGY

Descriptive study of MD incidence rates, serogroup distribution, case fatality rates (CFR), and MCV uptakes during the period 2010-2021 in Argentina, Brazil, Chile, and Uruguay. Data were extracted from national surveillance programs, reference laboratories, NIPs, and Pubmed.

RESULTS

MD overall incidence from 2010 to 2021 have a decreasing trend in Argentina (0.37 [IQR = 0.20-0.61]), Brazil (0.59 [IQR = 0.54-1.22]), and Chile (0.45 [IQR = 0.40-0.77]), while a significant increase in Uruguay (0.47 [IQR = 0.33-0.69]) was found from 2016 to 2019. During the COVID-19 pandemic, all countries sharply reduced their MD incidence. The highest incidence rates were observed among infants, followed by children 1-4 years of age. No second peak was evident in adolescents. A reduction in serogroup C, W, and Y cases has occurred in Argentina, Brazil, and Chile after introduction of MCV, serogroup B becoming predominant in all four countries. Median CFR was 9.0%, 21%, 19.9%, and 17.9% in Argentina, Brazil, Chile, and Uruguay, respectively. Median uptake of MCV for Argentina and Brazil were 66.6% and 91.0% for priming in infants; 54.7% and 84.5% for booster in toddlers; and 47.5% and 53% for adolescents; while for Chile, 95.6% for toddlers.

CONCLUSIONS

Experience after the implementation of MCV programs in South America was successful, reducing the burden of MD due to the vaccine serogroups. High vaccine uptake and the inclusion of adolescents will be crucial in the post-pandemic period to maintain the protection of the population. The increase in the proportion of serogroup B cases emphasizes the importance of continuous surveillance to guide future vaccination strategies.

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

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

Emergence of Neisseria meningitidis W South American sublineage strain variant in Brazil: disease and carriage

Introduction. Invasive meningococcal disease is a major health problem, impacting morbidity and mortality worldwide. Exploratory genomics has revealed insights into adaptation, transmissibility and virulence to elucidate endemic, outbreaks or epidemics caused by Neisseria meningitidis serogroup W (MenW) strains.Gap Statement. Limited information on the genomics of Neisseria meningitis serogroup W ST11/cc11 is available from emerging countries, especially in contemporary isolates.Aim. To (i) describe the antigenic diversity and distribution of genetic lineages of N. meningitidis serogroup W circulating in Brazil; (ii) study the carriage prevalence of hypervirulent clones in adolescents students and (iii) analyse the potential risk factors for meningococcal carriage.Methodology. Using whole-genome sequencing, we analysed the genomic diversity of 92 invasive N. meningitidis serogroup W isolates circulating in Brazil from 2016 to 2019. A cross-sectional survey of meningococcal carriage was conducted in 2019, in the city of Florianópolis, Brazil, among a representative sample of 538 students.Results. A predominance (58.5 %, 41/82) of ST11/cc11 presenting PorB2-144, PorA VR1-5, VR2-2, FetA 1-1, and a novel fHbp peptide 1241 was found on invasive N. meningitidis W isolates, on the other hand, a high diversity of clonal complexes was found among carriage isolates. The overall carriage rate was 7.5 % (40/538). A total of 28 of 538 swab samples collected were culture positive for N. meningitidis, including four serogroup/genogroup B isolates (14.8 %;4/27), 1 serogroup/genogroup Y isolate (3.7 %;1/27), 22 (81.5 %; 22/27) non-groupable isolates. No MenW isolate was identified among carriages isolates.Conclusion. This report describes the emergence of the new MenW ST11/cc11 South America sublineage variant, named here, 2016 strain, carrying a novel fHbp peptide 1241, but its emergence, was not associated with an increased MenW carriage prevalence. Continuous surveillance is necessary to ascertain the role of this sublineage diversification and how its emergence can impact transmission.

Invasive meningococcal disease in Chile seven years after ACWY conjugate vaccine introduction

BACKGROUND

A serogroup W (MenW) outbreak in Chile prompted a meningococcal vaccination campaign using tetravalent meningococcal-conjugate vaccines (MCV-ACWY) in children since 2012, followed by its introduction into the National Immunization Program (NIP) in toddlers from 2014. Direct protection was observed, but no indirect effects in other age-groups were evidenced. The aim of this study was to describe invasive meningococcal disease (IMD) cases in Chile between 2009 and 2019, and its trend after the introduction of MCV-ACWYs.

METHODS

IMD cases, cumulative incidence per 100,000 inhabitants, CFR, and vaccination uptake were described. Data were obtained from the Public Health Institute and NIP.

RESULTS

Overall-IMD cases increased in 2009-2014 period, followed by a decline in 2015-2019, focused in infants, children <5 years and people ≥60 years. Serogroup B (MenB) and MenW alternate its predominance. Median overall incidence was 0.6/100,000, increasing from 0.6/100,000 in 2009 to 0.8/100,000 in 2014, later decreasing to 0.4/100,000 in 2019. Median incidences for MenB, serogroup C (MenC) and Y (MenY) were 0.25/100,000, <0.01/100,000 and <0.01/100,000, respectively. Median MenW incidence was 0.53/100,000, increasing from 0.01/100,000 in 2009 to 0.56/100,000 in 2014, followed by a constant decline to 0.12 in 2019. Infants, children <5 years and adults ≥60 years were affected the most, with median incidences of 9.7, 0.9 and 0.93, decreasing to 1.3, 0.1 and 0.1/100,000 in 2019, respectively. Median overall-CFR was 19%, 7.5% for MenB and 24.5% for MenW. Median MCV-ACWY uptake was 93% CONCLUSION: Overall-IMD, MenW cases and incidence declined since 2015 after the MCV-ACWY introduction, while MenB, MenC and MenY have been stable. MenW incidence declined in all age groups, including non-immunized infants and people >60 years. Further analysis and a longer period of observation are needed to have a more robust conclusion about this epidemiological trend. By 2019, CFR remains high.