Invasive Meningococcal X Disease during the COVID-19 Pandemic, Brazil.

Invasive meningococcal disease persists as a fulminant disorder worldwide. Although cases caused by Neisseria meningitidis serogroup X (MenX) occur infrequently, outbreaks have been reported in countries in Africa in recent decades. We report 2 cases of MenX invasive meningococcal disease in São Paulo, Brazil, in 2021 and 2022, during the COVID-19 pandemic.

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

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.

Immune response to native NadA from Neisseria meningitidis and its expression in clinical isolates in Brazil.

A mAb against the NadA protein from Neisseria meningitidis strain 3006 (serosubtype B : 2b : P1.2 : P5.2,8) demonstrated strong bactericidal activity against Brazilian epidemic serogroup B strain N44/89 (B : 4,7 : P1.19,15 : P5.5,7) and a serogroup C strain, IMC 2135 (C : 2a : P1.5,2), but not against another serogroup C strain, N1002/90 (C : 2b : P1.3 : P5.8). The immunogenicity of native NadA in an outer-membrane vesicle (OMV) preparation was also tested. Serum from mice immunized with OMV from serogroup B strain N44/89, which contains the NadA protein, showed bactericidal activity against serogroup B and C strains possessing NadA. In dot-blot analysis of 100 serogroup B and 100 serogroup C isolates from Brazilian patients, the mAb to NadA recognized about 60 % of the samples from both serogroups. The molecular mass of the NadA protein from strain N44/89 determined by mass spectrometry was 37 971 Da and the peptide sequences were identical to those of NadA from N. meningitidis strain MC58.

Adjuvant can improve protection induced by OMV vaccine against Neisseria meningitidis serogroups B/C in neonatal mice.

Meningococcal outer membrane vesicle (OMV) vaccines are weak antigens in infants. This study aimed at investigating alternative adjuvants for induction of functional antibodies in newborn mice. Serogroup B/C anti-meningococcal vaccines, consisting of capsular polysaccharide from serogroup C (PSC) conjugated to OMV from one serogroup B serosubtype prevalent in Brazil, combined with OMV from another prevalent serosubtype, were tested in newborn and adult mice with the following adjuvants: aluminum hydroxide, MPL (monophosphoryl lipid A), Titermax and MF59. Total IgG, IgG avidity index determination and bactericidal assay were performed with sera from immunized mice. Antibodies induced against PSC in newborn mice showed avidity and bactericidal titers, similar to those obtained in adult mice, independently of the adjuvant. Evidence is presented that the inclusion of MF59 enhanced the immune response against OMV in newborn mice.

Incorporation of real-time PCR into routine public health surveillance of culture negative bacterial meningitis in São Paulo, Brazil.

Real-time (RT)-PCR increases diagnostic yield for bacterial meningitis and is ideal for incorporation into routine surveillance in a developing country. We validated a multiplex RT-PCR assay for Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae in Brazil. Risk factors for being culture-negative, RT-PCR positive were determined. The sensitivity of RT-PCR in cerebrospinal fluid (CSF) was 100% (95% confidence limits, 96.0%-100%) for N. meningitidis, 97.8% (85.5%-99.9%) for S. pneumoniae, and 66.7% (9.4%-99.2%) for H. influenzae. Specificity ranged from 98.9% to 100%. Addition of RT-PCR to routine microbiologic methods increased the yield for detection of S. pneumoniae, N. meningitidis, and H. influenzae cases by 52%, 85%, and 20%, respectively. The main risk factor for being culture negative and RT-PCR positive was presence of antibiotic in CSF (odds ratio 12.2, 95% CI 5.9-25.0). RT-PCR using CSF was highly sensitive and specific and substantially added to measures of meningitis disease burden when incorporated into routine public health surveillance in Brazil.

Optimization of the conjugation method for a serogroup B/C meningococcal vaccine.

A conjugate meningococcal vaccine against serogroup B/C consisting of capsular PS (polysaccharide) from serogroup C conjugated to OMV (outer membrane vesicle) from serogroup B would be a very useful vaccine in regions where there is a prevalence of both serogroups, for example in Brazil. For this purpose, the conjugation method that uses ADHy (adipic acid dihydrazide) as spacer and a carbodi-imide derivative, EDAC [1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide], as catalyser was optimized looking for synthesis yield and maintenance of the antigenicity of both components. The best synthesis conditions preserving the vaccine immunogenicity resulted in a final yield of approx. 17%. Immunogenicity of the vaccine was highest when 10% of the sialic acid residues of the PS were occupied by the ADHy spacer. Sterilization of the conjugate by filtration through a 0.22-microm-pore-size membrane resulted in a low recovery of protein and PS (approximately 50%), although the vaccine immunogenicity was maintained. Using gamma irradiation on freeze-dried sample, it was possible to maintain the integrity of OMV structure and, consequently, its ability to induce bactericidal antibodies.

Incorporation of real-time PCR into routine public health Surveillance of culture negative bacterial meningitis in Sao Paulo, Brazil

Real-time (RT)-PCR increases diagnostic yield for bacterial meningitis and is ideal for incorporation into routine surveillance in a developing country. We validated a multiplex RT-PCR assay for Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae in Brazil. Risk factors for being culture-negative, RT-PCR positive were determined. The sensitivity of RT-PCR in cerebrospinal fluid (CSF) was 100% (95% confidence limits, 96.0%–100%) for N. meningitidis, 97.8% (85.5%–99.9%) for S. pneumoniae, and 66.7% (9.4%–99.2%) for H. influenzae. Specificity ranged from 98.9% to 100%. Addition of RT-PCR to routine microbiologic methods increased the yield for detection of S. pneumoniae, N. meningitidis, and H. influenzae cases by52%, 85%, and 20%, respectively. The main risk factor for being culture negative and RT-PCR positive was presence of antibiotic in CSF (odds ratio 12.2, 95% CI 5.9-25.0). RT-PCR using CSF was highly sensitive and specific and substantially added to measures of meningitis disease burden when incorporated into routine public health surveillance in Brazil

Limitações no uso da técnica de contraimunoeletroforese (CIE) para o diagnóstico das meningites causadas por Haemophilus influenzae tipo b / Limitations in the use of counterimmunoelectrophoresis (CIE) for diagnosis of Haemophilus influenza type b meningitis

A contraimunoeletroforese (CIE) é uma técnica amplamente utilizada no Brasil para o diagnóstico laboratorial indireto de meningites causadas por Neisseria meningitidis (Men) dos sorogrupos A, B e C e Haemophilus influenzae (Hi) tipo b, desde a década de 1970. A introdução da técnica de PCR em tempo real (RT-PCR) na rotina diagnóstica das meningites causadas por Men, Hi e Streptococcus pneumoniae (Spn), no Instituto Adolfo Lutz, levou à identificação de resultados discrepantes entre as duas metodologias. O objetivo deste trabalho foi investigar 46 amostras com resultados de CIE positivos para Hib. Deste total, 26 amostras (57%) tiveram resultados caracterizados como falsos positivos para Hib, pois nenhuma delas foi positiva para este agente por RT-PCR e teste de látex. Destas, 21 (46%) foram positivas para Spn por RT-PCR e látex e 5 (11%) foram negativas tanto para Hib ou Spn por ambas as técnicas. Estes dados evidenciaram a alta porcentagem de resultados falsos positivos para o componente Hib obtidos pela técnica de CIE. Nós recomendamos o uso do látex ou RT-PCR e não a CIE para a detecção de Hib ou, então, o uso de um segundo teste para confirmar casos de Hib positivos por CIE.

Limitações no uso da técnica de contraimunoeletroforese (CIE) para o diagnóstico das meningites causadas por Haemophilus influenzae tipo b / limitations in the use of couterimmunoelectrophoresis (CIE) for diagnosis of Haemophilus influenzae type b meningitis

A contraimunoeletroforese (CIE) é uma técnica amplamente utilizada noBrasil para o diagnóstico laboratorial indireto de meningites causadas porNeisseria meningitidis (Men) dos sorogrupos A, B e C e Haemophilusinfluenzae (Hi) tipo b, desde a década de 1970. A introdução da técnica dePCR em tempo real (RT-PCR) na rotina diagnóstica das meningitescausadas por Men, Hi e Streptococcus pneumoniae (Spn), no InstitutoAdolfo Lutz, levou à identificação de resultados discrepantes entre as duasmetodologias. O objetivo deste trabalho foi investigar 46 amostras comresultados de CIE positivos para Hib. Deste total, 26 amostras (57%)tiveram resultados caracterizados como falsos positivos para Hib, poisnenhuma delas foi positiva para este agente por RT-PCR e teste de látex.Destas, 21 (46%) foram positivas para Spn por RT-PCR e látex e 5 (11%)foram negativas tanto para Hib ou Spn por ambas as técnicas. Estes dadosevidenciaram a alta porcentagem de resultados falsos positivos para ocomponente Hib obtidos pela técnica de CIE. Nós recomendamos o uso dolátex ou RT-PCR e não a CIE para a detecção de Hib ou, então, o uso de umsegundo teste para confirmar casos de Hib positivos por CIE

Doença meningocócica: investigação de surto comunitário no Distrito Administrativo do Ipiranga, município de São Paulo, julho de 2007 / Meningococcal disease: community outbreak investigation in the District of Ipiranga, city of São Paulo, in July, 2007

A Neisseria meningitidis, que comumente coloniza o trato respiratório humano, é uma causa importante de doença endêmica ou epidêmica. O objetivo desta investigação foi analisar a ocorrência de um surto de doença meningocócica (DM) no Distrito Administrativo (DA) do Ipiranga, na região Sudeste do município de São Paulo. Para tanto foram utilizados: bancos de dados de notificação rápida de DM e do SINANW e SINANNET do Centro de Prevenção e Controle de Doenças, da Secretaria Municipal de Saúde de São Paulo (CCD/COVISA/SMS-SP), o SIAB (Sistema de Informação de Atenção Básica), além de investigação de campo. Entre os dias 23 e 24/7 de 2007 foram notificados ao CCD/COVISA/SMS-SP três casos de DM em pacientes residentes na gleba N da comunidade Heliópolis, localizada no DA Ipiranga, dois dos quais por meningococo C, sem ocorrência de óbitos. Este DA vem apresentando uma média de 7,4 casos de DM nos últimos cinco anos, com coeficientes de incidência que variaram de 4,2 em 2002 a 10,2 por 100.000 habitantes em 2006, e no período e locais analisados a taxa de ataque foi 89,52 por 100.000 habitantes. Após a caracterização do surto, foi realizada, em 4/8, a vacinação da população de 2 meses a 14 anos. Uma atuação integrada entre as áreas assistencial, de vigilância epidemiológica (SUVIS, CCD, CVE) e laboratorial (IAL) é imprescindível para que se garanta a adoção de estratégias adequadas de controle da DM, a exemplo do que ocorreu neste surto.

Neisseria meningitidis serogroup C polysaccharide and serogroup B outer membrane vesicle conjugate as a bivalent meningococcus vaccine candidate

Neisseria meningitidis serogroup C polysaccharide (PS C) was conjugated to serogroup B outer membrane vesicles (OMV) in order to test the possibility of obtaining a bivalent group B and C meningococcus vaccine. The conjugate and controls were injected intraperitoneally into groups of ten mice with boosters on days 14 and 28 after the primary immunization. The following groups were used as control: (i) PS C; (ii) PS C plus OMV; (iii) OMV; and (iv) saline. The serum collected on days 0, 14, 28 and 42 were tested by enzyme-linked immunosorbent assay (ELISA) for PS C and OMV, and by complement mediated bactericidal assay against serogroups B and C. ELISA for PS C as well as bactericidal titres against serogroup C meningococci of the conjugated vaccine increased eight-fold (ELISA) and 32 fold (bactericidal) after 42 days in comparison with the PS C control group. ELISA for OMV and bactericidal titre against serogroup B meningococci of the conjugate showed no significant difference in comparison with the OMV containing controls. Furthermore, Western Blot assay of the conjugate immune serum did not bind OMV class four protein which is related to the complement dependent antibody suppressor. The results indicate that the PS C-OMV conjugate could be a candidate for a bivalent vaccine toward serogroups B and C meningococci.