Enfermedad meningocóccica invasora por serogrupo B en dos niños chilenos vacunados contra serogrupos ACWY / Meningococcal invasive disease caused by serogroup B in two Chilean children vaccinated against ACWY serogroups

Invasive meningococcal disease (IMD) by serogroup W has become predominant in Chile since 2012, prompting vaccination with conjugate ACWY. We reported two pediatric cases in patients already vaccinated, which evolved with IMD by serogroup B. This should remind us to keep the alertness with this pathology, despite the current vaccination system in Chile, emphasizing in improve our epidemiological case definition and its diagnosis.

La Enfermedad Meningocóccica Invasora (EMI) por serogrupo W ha llegado a ser predominante en Chile desde el 2012, motivando estrategias de inmunización con vacunas conjugadas contra los serogrupos ACWY. Presentamos dos casos pediátricos de pacientes vacunados contra meningococo ACWY que evolucionaron con EMI por serogrupo B, lo que debe recordarnos la alerta y sospecha de esta patología, inclusive con el esquema de vacunación actual chileno, poniendo énfasis en mejorar nuestra definición epidemiológica de caso sospechoso para optimizar su diagnóstico.

Investigation on the monoclonal antibodies as differential markers for viral and bacterial meningitis by means of immnunohistochemistry technique / Avaliação de anticorpos monoclonais como marcadores diferenciais de meningites bacterianas e virais por meio de técnica imuno-histoquímica

Since 1996, the Laboratory of Monoclonal Antibodies Antigens and Adjuvants - Immunology Center of Adolfo Lutz Institute (IC-IAL) has been working on N. meningitidis strains antigens characterization by using a predetermined monoclonal antibodies (MoAb) panel; and the new monoclonal production has been performed for characterizing strains with unknown profiles. MoAb were obtained from different fusions performed at IAL using spleen cells and popliteal lymph nodes. Two murine hybridomas secreting MoAb anti-N. meningitidis antigens, produced and characterized in the Laboratory of IC-IAL, are presently being evaluated by immunohistochemical (IHC) technique at Immunohistochemistry Laboratory - Pathology Center, IAL. After standardizing these reactions, a protocol for performing investigation on N.meningitidis antigens by using IHQ was established. An increment in the histopathological diagnosis of meningococcal meningitis was occurred, by using MoAb specific for antigens from N. meningitidis serogroups, serotypes and subtypes, mainly in those cases without microorganisms confirmation by biomolecular techniques as PCR. The results obtained in these first tests proved to be promising, and two MoAb showed excellent results. No cross-reactivity with viral meningitis, S. pneumoniae, Rickettsia or Rubella was detected. For the further studies, it is fundamental to increase the samples size, including samples from patients with meningococcal meningitis and from individuals infected with other pathogens.

Desde 1996, o Laboratório de Anticorpos Monoclonais, Antígenos e Adjuvantes - Centro de Imunologia do Instituto Adolfo Lutz (CI-IAL) tem desenvolvido trabalhos na caracterização antigênica de cepas de Neisseria meningitidis utilizando-se painel de anticorpos monoclonais (AcMo) pré-estabelecido, e produção de novos monoclonais para a análise de cepas com perfis desconhecidos. AcMo foram obtidos das diferentes fusões realizadas no laboratório utilizando-se células esplênicas e linfonodos poplíteos. Dois hibridomas murinos secretores de AcMo anti-N. meningitidis produzidos e caracterizados no CI-IAL têm sido avaliados por meio de estudo imuno-histoquímico (IHQ) no Centro de Patologia-Laboratório de Imunohistoquímica-IAL. Com a padronização da reação, estabeleceu-se um protocolo para efetuar a pesquisa de antígenos de N. meningitidis por IHQ. Houve melhoria no diagnóstico histopatológico da meningite meningocócica, sobretudo em situações em que não há confirmação da presença do microorganismo por técnicas biomoleculares, como PCR, utilizando-se AcMo específicos para antígenos de diferentes sorogrupos, sorotipos e subtipos de N. meningitidis. O resultado obtido nos primeiros testes mostrou-se promissor, e os dois AcMo demonstraram excelentes resultados. Não houve reatividade cruzada com meningite viral, S. pneumoniae, Rickettsia ou rubéola. Nos próximos estudos, é fundamental ampliar número de amostras, incluindo-se aquelas coletadas de pacientes com meningites meningocócicas e de indivíduos infectados com outros agentes patogênicos.

Meningococcal disease before and after the introduction of meningococcal serogroup C conjugate vaccine. Federal District, Brazil

OBJECTIVES: To analyze the behavior of meningococcal disease in the Federal District, Brazil, from 2005 to 2011, and to assess the direct impact of the meningococcal serogroup C conjugate vaccine. METHODS: A descriptive study of cases of meningococcal disease among residents of the Federal District. We included in the study confirmed cases of meningococcal disease reported to the local surveillance. To reduce underreporting we compared data to the Brazilian Mortality Database and the Public Health Laboratory Database. We studied sociodemographic, clinical, and pathogen-related variables. For the assessment of the impact of meningococcal serogroup C conjugate vaccine, which was introduced in 2010 for children under two years of age, we compared the incidence of meningococcal disease before and after vaccine introduction in the recommended age groups for vaccination. RESULTS: We identified 309 cases of meningococcal disease, of which 52.1% were males. The average case fatality rate was 20.7%, the median age was three years and there was a predominance of serogroup C (70.2%) and C:23:P1.14-6 phenotype throughout the study period. In 2005-2009, 2010 and 2011, the incidence rates of meningococcal disease were 2.0, 1.8 and 0.8/100,000 inhabitants/year, while mortality rates were 0.4, 0.4 and 0.2/100,000 inhabitants/year, respectively. In the first and last periods, the incidence in poorer and more affluent areas were, respectively, 2.0 and 0.8, and 0.9 and 0.0/100,000 inhabitants/year. Comparing 2009 (the year prior to the introduction of meningococcal serogroup C conjugate vaccine) and 2011, there was 85% reduction in the incidence of serogroup C meningococcal disease in children under four years of age, from 9.0 to 1.3/100,000 (p < 0.01). CONCLUSIONS: The meningococcal serogroup C conjugate vaccine strategy implemented in Brazil proved highly effective and had a strong direct impact on the target population. However, case ...

Short-term and long-term antibody response by mice after immunization against Neisseria meningitidis B or diphtheria toxoid

Serogroup B Neisseria meningitidis (MenB) is a major cause of invasive disease in early childhood worldwide. The only MenB vaccine available in Brazil was produced in Cuba and has shown unsatisfactory efficacy when used to immunize millions of children in Brazil. In the present study, we compared the specific functional antibody responses evoked by the Cuban MenB vaccine with a standard vaccine against diphtheria (DTP: diphtheria, tetanus, pertussis) after primary immunization and boosting of mice. The peak of bactericidal and opsonic antibody titers to MenB and of neutralizing antibodies to diphtheria toxoid (DT) was reached after triple immunization with the MenB vaccine or DTP vaccine, respectively. However, 4 months after immunization, protective DT antibody levels were present in all DTP-vaccinated mice but in only 20% of the mice immunized against MenB. After 6 months of primary immunization, about 70% of animals still had protective neutralizing DT antibodies, but none had significant bactericidal antibodies to MenB. The booster doses of DTP or MenB vaccines produced a significant antibody recall response, suggesting that both vaccines were able to generate and maintain memory B cells during the period studied (6 months post-triple immunization). Therefore, due to the short duration of serological memory induced by the MenB vaccine (VA-MENGOC-BC® vaccine), its use should be restricted to outbreaks of meningococcal disease.

[Identification of serological groups A, B, C, W135, Y, X Neisseria meningitidis carriers by multiplex PCR in the nasopharynx of students in Kashan during 2011-2012]

Neisseria meningitidis [N. meningitidis] is a pathogen which colonizes in the nasopharynx without any clinical manifestations. Among the 13 different serological groups, only the serogroups A, B, C, W135, Y, X play a major role in disease development. This study aimed to determine N. meningitidis cases carrying these serological groups using the multiplex PCR method in the nasopharynx of students in Kashan schools. This cross-sectional study was conducted on 1289 students in Kashan during 2011-2012. Samples were collected from the students' nasopharynx using a sterile swab and cultured on a selective medium. Strains were identified through biochemical tests. Then the serological groups were determined using the multiplex PCR method. One-hundred and fifteen [8.9%] out of 1289 students were N.meningitidis carriers; 75 [65.2%] male and 40 [34.8%] female. There was a significant difference between gender and the rate of carriers [P=0.032]. The highest rate of carriers [12.3%] was in the 15 to 19 year age group. There was a significant relationship between the rate of carriers and increase in the number of family members [P<0.001]. In this study, only the serological groups B [8 cases] and C [107 cases] were detected. Since the serological group C is involved in the outbreak and there is no vaccine currently available for the serological group B to prevent the infection, detection of these serological groups can be important

Infection and immune-mediated meningococcal-associated arthritis: combination features in the same patient / Artrite meningocócica mediada imunologicamente e associada à infecção: combinação de ambas características no mesmo paciente

We present a case of a 16-year-old male patient with sudden-onset, rash, arthritis and meningitis by Neisseria meningitidis one week after an acute upper respiratory infection. On the 10th day of treatment followed by neurological and arthritis clinical improvement, he presented once again a tender and swollen left knee with a moderate effusion, and active and passive range of motion was severely limited secondary to pain, and when he was submitted to surgical drainage and synovial fluid analysis he showed inflammatory characteristics. A non-steroidal anti-inflammatory drug was taken for five days with complete improvement of symptoms. The case is notable for its combination of features of septic and immune-mediated arthritis, which has rarely been reported in the same patient.

Paciente de 16 anos do sexo masculino apresentou-se ao serviço de emergência com quadro de erupção cutânea súbita, artrite e meningite por Neisseria meningitidis, uma semana após apresentar sintomas de infecção de vias aéreas superiores. No décimo dia de tratamento, seguido da melhora clínica neurológica e da artrite, ele volta a apresentar derrame articular moderado com limitação importante da amplitude dos movimentos passivo e ativo secundária à dor. Em seguida, foi submetido à drenagem cirúrgica e a análise do líquido sinovial mostra características inflamatórias. Foi iniciado tratamento com antiinflamatório não esteroidal por cinco dias com melhora completa dos sintomas. Esse caso tem como característica peculiar o fato do indivíduo apresentar tanto as características de artrite séptica pelo meningococo quanto de artrite imunomediada, o que tem sido pouco usual no mesmo paciente.

Cinética do cultivo de Neisseria lactamica em biorreator / Bioreactor cultivation kinetics of Neisseria lactamica

Neisseria lactamica está envolvida na aquisição da imunidade natural contra Neisseria meningitidis, causadora da doença meningocócica. Vesículas de membrana externa (OMV) de N. lactamica são antígenos potenciais contra N. meningitidis. Analisou-se a cinética de biomassa, de produção de OMV, da fonte de carbono (lactato), e dos metabólitos, para maximizar a produção de OMV. Realizaram-se ensaios em biorreator, em batelada simples, batelada alimentada com lactato, com ou sem pulsos de aminoácidos e extrato de levedura (YE). Utilizou-se o meio de Catlin (MC) como meio mínimo, e analisaram-se efeitos das concentrações do lactato, aminoácidos e YE. Lactato foi consumido e citrato e acetato produzidos. Os melhores resultados obtidos foram no meio com adição de 2 g/L de YE e concentrações dobradas de lactato e 5 aminoácidos constitutivos do MC, em batelada alimentada com pulsos. O lactato apresentou efeito positivo sobre o rendimento de OMV e o YE sobre a biomassa. Os 5 aminoácidos constitutivos do MC foram necessários para obtenção de biomassa e rendimento de OMV.

Neisseria lactamica is involved with the acquisition of natural immunity to Neisseria meningitidis. N. lactamica outer membrane vesicles (OMV) are potential antigens against N. meningitidis, the pathogen of meningococcal disease. The objective of this work was to analyze the kinetics of bacterial growth, OMV production, the carbon source (lactate), and products of metabolism, to improve growing conditions and OMV production. Groups were studied in batch process, fed-batch process with lactate, fed-batch process with pulses of amino acids and YE. MC was considered as minimal medium and it was analyzed the effect of lactate, amino acids and YE. Lactate was consumed and citrate and acetate increased in the medium. The best results were in fed-batch with pulses, in MC with the double concentrations of lactate and amino acids, added with 2 g/L of YE. The lactate had a positive effect over OMV yield and YE had a positive effect over biomass. 5 amino acids of MC were necessary to obtain biomass and OMV yield.

Introduction of Nm A conjugate vaccine in Sudan

Sudan, with support from GAVI Alliance and technical cooperation from WHO is planning to introduce Neisseria meningitides [Nm] A conjugate vaccine in in 2012. Over 24.78 million people between the 1-29 year age group living in some of the high risk states of the country will be vaccinated in two phases. In 2012, during the first phase, some of the most high risk states will be covered. The remaining states which are prone to repeated outbreak from meningococcal meningitis will be covered in second phase starting in 2013

Detección de cepas de Neisseria meningitidis resistentes a rifampicina en el Uruguay / Detection of rifampicin-resistantstrains of Neisseria meningitidis in Uruguay

El objetivo de este trabajo fue caracterizar fenotípica y genotípicamente dos aislamientos deNeisseria meningitidis resistentes a rifampicina relacionados con dos eventos independientes de transmisión de enfermedad meningocócica grave que se presentaron en septiembre y octubre de 2010 en Montevideo, Uruguay. Se revisó también la base de datos de la vigilancia nacional de resistencia a los antimicrobianos de los últimos 10 años, para estimar la frecuencia de la particularidad de los meningococos caracterizados. La resistencia a rifampicina se estudiópor el método epsilométrico. El serotipo y serosubtipo de los aislamientos se determinaron por ELISA y la caracterización genotípica se realizó por digestión del ADN con NheI y electroforesis en gel con campo pulsátil. Ambos aislamientos eran idénticos, B:2a:P1.5, y su fenotipo no figuraba en la colección de 408 cepas de N. meningitidis aisladas en el Uruguayen los últimos 10 años, con la excepción de dos aislamientos sensibles a rifampicina. Los dos aislamientos estudiados también compartían un pulsotipo único, diferente del de otros dos aislamientos resistentes a rifampicina obtenidos en 2003 y 2007. Por lo tanto, ambos eventos detransmisión fueron causados por una única cepa resistente a rifampicina, que podría haberse introducido al país desde otras regiones o haberse originado por un cambio del serogrupo C al B, como producto de la presión selectiva ejercida por vacunas administradas a la población. Es necesario mantener y extremar la vigilancia. No obstante, en vista de que hasta el momento este tipo de hallazgo ha sido esporádico, no se justifica cambiar el fármaco antimicrobiano que se administra a los contactos para la profilaxis, a menos que se identifique un caso secundario.

The objective of this study was to characterize the phenotype and genotype of two isolates of rifampicin-resistant Neisseria meningitidis associated with two independentevents involving transmission of severe meningococcal meningitis that occurredin September and October 2010 in Montevideo, Uruguay. The most recent 10 years of data from the national antimicrobial resistance surveillance system were reviewed to estimate the frequency of the particular meningococcal features thatwere characterized. Rifampicin resistance was studied using the epsilometer test. The serotype and serosubtype of the isolates were determined by ELISA, and thegenotype was characterized using DNA digestion with Nhel and pulse field gelelectrophoresis. The two isolates were identical: B:2a:P1.5. In the collection of 408 strains of N. meningitidis isolated in Uruguay in the past 10 years, the phenotype only appeared in two isolates, which were sensitive to rifampicin. The two isolates studiedalso shared a single pulse type, which was different from that of two other rifampicinresistant isolates obtained in 2003 and 2007. Consequently, it was concluded that both cases of transmission were caused by a single rifampicin-resistant strain, whichcould have been an import from another country or else the result of a drift fromserogroup C to B due to selective pressure exerted by vaccines administered to the population. It is essential to maintain and maximize surveillance. However, since thistype of finding has been sporadic so far, unless a secondary case is identified, there is no justification for changing the antimicrobial drug currently being administered to contacts as prophylaxis.

Comparison of dot-ELISA and standard ELISA for detection of Neisseria meningitidis outer membrane complex-specific antibodies

Dot-ELISA using the outer membrane complex antigens of Neisseria meningitidis as a target was standardized for rapid detection of meningococcal-specific antibodies in human serum. We investigated the level of meningococcal-specific IgG, IgA, and IgM in serum using dot-ELISA with outer membrane antigens prepared from Neisseria meningitidis serotype B:4.19:P1.15,3,7,9 (a strain isolated from a Brazilian epidemic). The dot-ELISA is based on the same principles as the standard ELISA and is useful for detection of anti-N. meningitidis B antibodies in serum of patients with meningococcal infections. For the assay, outer membrane complexes (OMCs) were absorbed by nitrocellulose membrane and blocked with a 5 percent skim milk solution. Serum samples were drawn upon hospital admission and during convalescence from patients with meningococcal septicemia, and single samples were drawn from uninfected controls. We retrospectively examined a total of 57 serum samples: 35 from patients infected with N. meningitidis B, 12 from patients infected with Haemophilus influenzae b, and 10 from health individuals. When performed at room temperature, dot-ELISA took approximately four hours to perform, and the optimum antigen concentration was 0.42 µg per dot. The specificity of IgG, IgM, and IgA demonstrates that dot-ELISA using OMCs from N. meningitidis B as a target is suitable for serologic verification of clinically suspected meningococcal disease in patients and for titer determination of antibodies produced during different phases of natural infection. Furthermore, the sensitivity of dot-ELISA was comparable to that of standard ELISA. Overall, dot-ELISA is simple to perform, rapid, and low cost. Further validation of the test as a screening tool is required.

Antibióticos y resistencia antibiótica en la quimioprofilaxis de la enfermedad meningocócica / Antibiotics and antibiotic resistance in chemoprophylaxis of meningococcal disease

La profilaxis antibiótica debe considerarse en personas con contacto con algún caso de enfermedad meningocócica o en poblaciones con altos porcentajes de portadores de N. meningitidis. El uso de antibióticos produce una reducción significativa del riesgo de enfermedad entre los contactos; así, la rifampicina, la ciprofloxacina y la ceftriaxona se consideran como las mejores opciones para la quimioprofilaxis, sin embargo su empleo está asociado con el aumento de resistencia antibiótica. Actualmente, la tendencia a la aparición de meningococos resistentes a la rifampicina después de la profilaxis es un aspecto reconocido, aunque parece que no es un fenómeno ampliamente extendido. La aparición de resistencia de alto nivel a la rifampicina está provocada por mutaciones en el gen rpoB, aunque se puede asociar a mutaciones del locus mtr implicadas en mecanismos de expulsión y bombeo. Sin embargo, los cambios en el gen rpoB dan lugar a cepas poco adaptadas a la supervivencia y este costo biológico podría explicar la ausencia de diseminación clonal de los aislamientos con resistencia adquirida a la rifampicina. La resistencia o sensibilidad disminuida a la ciprofloxacina se relaciona con mutaciones en la región determinante de resistencia a quinolonas (QRDR) del gen gyrA, además existen datos que apoyan la existencia de mecanismos de expulsión. Hasta el momento, la resistencia o la sensibilidad reducida a las quinolonas ha avanzado lentamente. No se han comunicado problemas de resistencia a la ceftriaxona, siendo la opción más segura para su uso en quimioprofilaxis.La espiramicina no es una opción adecuada aunque sigue siendo recomendada por la OMS.

Vacinas meningocócicas conjugadas: eficácia e novas combinações / Meningococcal conjugate vaccines: efficacy and new combinations

OBJETIVO: A doença meningocócica é, ainda hoje, um sério problema de saúde pública, estando associada a elevadas taxas de morbidade e letalidade no mundo e, em especial, no Brasil. Além de discutir as recentes mudanças na epidemiologia da doença meningocócica no mundo, analisamos o desenvolvimento e o impacto das novas vacinas conjugadas na prevenção da doença meningocócica, com ênfase nas diferentes estratégias de imunização utilizadas com essas vacinas. FONTE DOS DADOS: Foram pesquisadas as bases de dados MEDLINE no período de 1996 a 2006, com destaque para artigos de revisão, ensaios clínicos e epidemiológicos. Também foi realizada busca de informações nos portais do Centro de Controle de Doenças, Ministério da Saúde do Brasil e Centro de Vigilância Epidemiológica do Estado de São Paulo. SíNTESE DOS DADOS: Cinco sorogrupos (A, B, C, W135 e Y) respondem por virtualmente todos os casos da doença no mundo, com marcantes diferenças regionais e temporais. As novas vacinas conjugadas contra o meningococo C apresentam inequívocas vantagens em relação às vacinas polissacarídicas. Induzem uma resposta de anticorpos mais eficiente e duradoura, propiciando memória imunológica e redução da incidência de portadores. Os resultados imediatos da introdução dessas vacinas nos programas de imunização foram animadores, com dramática redução da incidência de doença, inclusive em não-vacinados (imunidade de rebanho). Entretanto, recentemente constatou-se perda da eficácia após alguns anos da aplicação da vacina, especialmente entre os lactentes vacinados. CONCLUSÕES:A perda de efetividade das vacinas conjugadas contra o meningococo C, observada após alguns anos da imunização de lactentes jovens, justifica a mudança dos esquemas de vacinação, com a incorporação de uma dose de reforço entre 12 e 18 meses de idade para garantir uma proteção mais duradoura. O recente licenciamento da vacina quadrivalente meningocócica conjugada representa, enfim, a real possibilidade de uma proteção mais abrangente contra a doença meningocócica, restando ainda a necessidade de se desenvolver uma vacina eficaz contra o meningococo B.

Production of monoclonal antibody to subtype 9 of Neisseria meningitidis and the distribution of this subtype in Brazil

A new monoclonal antibody (5F81A4P1.9), which is specific for subtype 9 antigen of meningococci, was studied. The antibodies were raised against a previously non-typable (NT) serogroup B strain from Brazilian patients and were found to react with the subtype antigen of prototype reference strains for subtype 9 (M982), as well as with those of homologous strains. The subtype 9 epitope was found in 6.8 percent of serogroup B strains among 602 strains of Neisseria meningitidis case isolates, including representative isolates from Brazilian states. Subtype P1.9 was predominantly related to serogroup B in Brazil among the isolates collected during the N. meningitidis epidemic in 1992. No significant differences were observed in the occurrence of subtype P1.9 among strains isolated from several Brazilian states. Fluorescence-activated cell-sorter analysis showed that 5F81A4 MAb recognized a 46 kDa protein on the surface of a homologous strain of N. meningitidis (B:4:P1.9). These results, in association with a bactericidal activity assay for 5F81A4, and with experimental passive protection in mice, demonstrated the importance of subtype 9 class 1 proteins of N meningitidis in Brazil. Serotyping is essential for the development of vaccination strategies.

Conjugate vaccines--a breakthrough in vaccine development.

The encapsulated bacteria Streptococcus pneumoniae (the pneumococcus), Neisseria meningitidis (the meningococcus) and Haemophilus influenzae type b (Hib) are the main causes of purulent meningitis, the peak incidence of which is seen in the first two years of life. The polysaccharide capsule of these bacteria is an essential virulence determinant, and antibodies to it are protective, suggesting that a polysaccharide vaccine could prevent these diseases. The young child is, however, unable to respond with antibody production to these polysaccharides, making such vaccines useless in infancy. Conjugation of the polysaccharide to a protein carrier has proven a way to solve the problem. Immunization of infants with such a Hib conjugate vaccine was shown in 1987 to result in the desired antibody production and protection from Hib meningitis and bacteremia. The Hib vaccine is now a part of national infant immunization programs in large parts of Europe, the Americas and Australia, and has resulted in the virtual disappearance of Hib disease from these areas. A group C meningococcal and 7-valent pneumococcal vaccine, available since 2000, are likewise proving highly effective in preventing bacteremic disease. Further advantages of the conjugate vaccines are their ability to elicit immunologic memory and to reduce asymptomatic carriage of the bacteria, resulting in marked herd immunity. This paper was delivered as a lecture in January 2003 in Bangkok on the occasion of the Prince Mahidol Award for a life's work in the field of vaccinology.

Typing and susceptibility to penicillin of Neisseria meningitidis isolated from patients in Cuba (1993-1999)

The susceptibility to penicillin of 111 Neisseria meningitidis strains was assessed by the agar-dilution procedure and serosubtypes were determined by a whole-cell enzyme-linked immunoassay using monoclonal antibodies reagents. Thirty-five isolates showed reduced sensitivity to penicillin (MIC > or = 0.1 mg/l and <= 1 mg/l) and no resistant strains were detected. The most common phenotype was B:4:P1.15 (77.5 percent) and a rising trend of non-typeable and non-subtypeable strains was detected. The increase in levels of minimal inhibitory concentrations of meningococci to penicillin gives cause for concern and the increase in non-typeable and non-subtypeable isolation demand the use of molecular biology techniques for their typing

The Epidemiological Impact of Antimeningococcal B Vaccination in Cuba

The incidence of invasive meningococcal disease (IMD) before (1984-1988) and after (1989-1994), a nationwide intervention with VA-MENGOC-BC vaccination started in 1989, was compared. The prevaccination period incidence density (ID> 8.8/ 105 year-person) was higher than the postvaccination ID (ID< 6.5/ 105 year-person). The percentage proportional differences from the start to the end of each period of ID in the vaccinal period was higher (87 percent) than the prevaccinal (37 percent) with significant differences among vaccinated groups (< 25 years old). A break-point (Chow test) was confirmed by the decrease in the ID between 1989 and 1990 in children under 1 year old, 5-9, 10-14, 15-19 and 50-54 years. Comparison of ID using maps showed a decrease in IMD in all municipalities during the postvaccination period. These findings support the epidemiological impact of VA-MENGOC-BC vaccination in the reduction of IMD morbidity

Estado actual y desarrollo de nuevas vacunas anti meningocóccicas / Update and development of new meningococcal vaccines

Las vacunas anti meningocóccicas A y C han demostrado su eficacia en adultos y niños mayores aunque no estimulan poblaciones de LB de memorias impidiendo con efecto booster a años plazo. Además adolecen de una escasa inmunogenicidad y/o eficacia en lactantes (bajas 3 y 12 meses de edad respectivamente) y una breve duración de la protección otorgada a aquellos que desarrollaron anticuerpos específicos. La conjugación con diferentes proteínas, al igual a lo realizado con el poli ribofosfato de H. influenzae b, mejora su inmunogenicidad y permite constatar la aparición de memoria inmunológica contra el grupo C en ensayos efectuados en lactantes. Se espera establecer si esta vacunas conjugadas conferirán inmunidad de rebaño como consecuencia de disminuir la infección faríngea en individuos vacunados. Las vacunas anti meningococcicas contra el grupo B elaboradas al momento actual con PME, son específicas contra el serotipo y subtipo contenidos en la vacuna. No han sido exitosa en niños pequeños a quienes más interesa proteger. Por carecer de validez universal, se ensayan actualmente estrategias para conferirles polivalencia mediante la recombinación genética de cepas que expresen PME de diversos tipos y subtipo. Se está trabajando activamente también en la evaluación de vacunas en que se ha incorporado el PS del grupo B (modificado sustituyendo el grupo acetil por propionil en el ácido neuramínico), como antígeno principal unido a PME de clase 1 recombinantes