Investigation on the carriage prevalence of Neisseria meningitidis in healthy population in Jiangsu Province in 2019 and 2020 / 中华预防医学杂志

In order to investigate carriage status and serum groups distribution of Neisseria meningitidis(Nm) among healthy population in Jiangsu Province, four counties were selected as monitoring sites by random sampling method for cross-sectional study. Throat swab specimens were collected from four monitoring sites in October to November 2019 and November to December 2020 for bacterial culture and Real-time PCR detection. Chi-square test was used to compare the positive rate of Neisseria meningitidis, and multiple logistic regression model was used to analyze the influencing factors of Neisseria meningitidis carrier rate. The results showed that among 1 512 samples, 57 strains of Nm were isolated, and the carrier rate was 3.77%. Serogroup B was the dominant group (36.84%), followed by un-known serogroups (33.33%), serogroup C was the third (17.54%), serogroup W135 and serogroup A were 7.02% and 5.26%, respectively. The carriage rate (8.60%) of 15-20 years old was significantly higher than others (1.77%-3.74%)(Pearson χ2=18.211, P<0.05). Region, age and immunization history were risk factors for Neisseria meningitidis carrier rate. In summary, the Nm carrier rate of healthy population in Jiangsu Province is relatively low, which indicates that the epidemic cases will continue to be sporadic in the future. However, the prevention and control of meningococcal epidemics on campus should be strengthened, and the monitoring of neisseria meningitidis group B should be maintained as it has become the dominant epidemic strain.

Priorización de nuevas vacunas e innovación al servicio de estrategias de vacunación / New vaccines prioritization and immunization-related innovation

La vacunación es el medio más efectivo para controlar la morbilidad y mortalidad relacionadas con enfermedades infecciosas. Para lograr esto, necesitamos vacunas inmunogénicas y seguras que faciliten y mejoren sus condiciones de transporte, almacenamiento y administración. Gracias a los avances en inmunología y bioinformática, es posible impulsar el descubrimiento de nuevas vacunas para enfrentar la tuberculosis, el virus respiratorio sincicial, el Streptococcus agalactiae, la enfermedad meningocócica invasora, entre otros. Así también, nuevas tecnologías, como la producción de vacunas utilizando plantas transgénicas y parches de microagujas, los cuales podrían facilitar la producción, disminuir los costos y efectos adversos. Sin embargo, no solo necesitamos las vacunas, sino que debemos conocer la epidemiología de las enfermedades prevenibles con vacuna para tomar decisiones fundadas, con el objetivo de planificar estrategias sanitarias, medir su impacto y evaluar la seguridad de su utilización, para alcanzar las metas de salud pública y la confianza de la población.

Vaccination is the most effective strategy to avoid morbidity and mortality related to infectious diseases. To achieve this, we need immunogenic and safe vaccines that facilitate and improve its transport, storage and administration conditions. Thanks to current advances in immunology and bioinformatics, it is possible to boost the discovery of new vaccines to deal with tuberculosis, the respiratory syncytial virus, Streptococcus agalactiae, meningococcal invasive disease, among others. In addition to new technologies such as the production of plant-based vaccines, and microneedles patches, which can facilitate its production, reducing costs and adverse effects. However, vaccines is not the only thing that we need, because we must know the epidemiology and burden of disease to take informed decisions to design optimal strategies, measuring their impact and assessing the safety of their use in order to achieve the goals health and population confidence.

Plan de acción nacional frente a la emergencia de la cepa W-135 responsable de enfermedad meningocócica invasora en Chile, 2012-2013 / National action plan for the emergence of invasive meningococcal disease in Chile, 2012-2013

Invasive meningococcal disease is challenging for public health, mainly when it manifests with sudden changes in incidence, serogroups and hypervirulent clones that spread in the population, causing great alarm due to its sequelae and often fatal course, a situation that occurred in Chile, starting at week 26 of the year 2012. To face this scenario, an organization of multidisciplinary teams was required, called W-135 Action Plan in Chile, which included sanitary alerts, education, reinforcement of the epidemiological surveillance of suspicious cases, immediate diagnosis through state-of-the-art techniques, blocking of contacts, communication plans, and, from the 42nd week, ON the vaccination campaign was started for children aged from 9-months-old to less than 5 years of age. The vaccination strategy had a great impact on the decrease in incidence (1.3 to 0.1/100,000) and case fatality rate in the vaccinated population (23% to 0%), with a high safety profile, leading to its subsequent inclusion in the national immunization program. The ability to develop molecular, clinical and epidemiological studies allowed us to better understand the situation, supporting public health policy decisions for its control. The W-135 Action Plan implemented by the Ministry of Health in Chile, to manage the outbreak of meningococcal disease by Neisseria meningitidis serogroup W, demonstrated that the coordination of these efforts, through an organized Action Plan, allows the implementation of campaigns at the national level achieving high coverage of risk populations in short periods of time, generating a positive impact on the health of the population.

Antibody persistence following meningococcal C conjugate vaccination in children and adolescents infected with human immunodeficiency virus / Persistência de anticorpos seguida de vacina conjugada meningocócica C em crianças e adolescentes infectados por vírus da imunodeficiência humana

Abstract Objective: HIV-infected individuals (HIVI) are threatened by meningococcal infection and presented lower response to vaccines. Data are scarce on long-term persistence of human serum bactericidal antibody (hSBA) after a meningococcal C conjugate (MCC) vaccine in HIVI youth; the authors aimed to describe this persistence in HIVI. Methods: HIVI and HIV uninfected individuals (HIVU), aged 2-18 years, CD4 >15% were recruited. Seroprotection (hSBA ≥1:4) at baseline and at 12-18 months after immunization was evaluated and the association of the different factors with the long-term persistence was calculated using logistic regression. Results: A total of 145 HIVI, 50 HIVU were recruited and immunized, and their median age was 11 years (median age in HIVI group was 12 years, and 10 years in HIVU group, p-value = 0.02). 85 HIVI (44%) had undetectable viral load (UVL). Seroprotection rate was 27.2%: 24.1% in HIVI and 36% in HIVU 12-18 months after immunization (p = 0.14). Baseline immunity (odds ratio [OR] = 70.70, 95% CI: 65.2-766.6); UVL at entry (OR: 2.87, 95% CI: 0.96-8.62) and lower family income (OR: 0.09, 95% CI: 0.01-0.69) were associated with seroprotection among HIVI. Conclusion: Seroprotection at 12-18 months after single dose of MCC was low for both groups, and higher among individuals who presented baseline immunity. Among HIVI, vaccine should be administered after UVL is achieved.

Resumo Objetivo: As pessoas infectadas pelo HIV (HIVI) estão sujeitas a infecção meningocócica e apresentam menor resposta a vacinas. São escassos os dados a respeito da persistência de longo prazo do anticorpo bactericida no soro humano (hSBA) após vacina conjugada meningocócica C (MCC) em HIVI jovens e visamos a descrever essa persistência em HIVI. Métodos: Foram recrutadas pessoas HIVI e pessoas não infectadas por HIV (HIVU), entre 2 e 18 anos, CD4 > 15%. A seroproteção (hSBA ≥ 1:4) basal aos 12-18 meses após a imunização foi avaliada e a associação dos diferentes fatores com a persistência de longo prazo foi calculada com a regressão logística. Resultados: Foram recrutados 145 HIVI e 50 HIVU e imunizados e sua idade média foi determinada em 11 anos (12 no grupo HIVI e 10 no grupo HIVU, valor de p = 0,02); 85 HIVI (44%) apresentaram carga viral indetectável (CVI). A taxa de seroproteção foi 27,2%: 24,1% no grupo HIVI e 36% no grupo HIVU 12-18 meses após imunização (p = 0,14). A imunidade basal [razão de chance (RC) = 7070, IC: 65,2-7666]; CVI no momento da participação (RC: 2,87, IC de 95%: 0,96-8,62) e renda familiar mais baixa (RC: 0,09, IC de 95%: 0,01-0,69) foram associadas a seroproteção entre as pessoas HIVI. Conclusão: A seroproteção aos 12-18 meses após única dose de MCC mostrou-se baixa em ambos os grupos e mais elevada entre as pessoas que apresentaram imunidade basal. Entre as pessoas HIVI, as vacinas devem ser administradas após a CVI ser atingida.

Evaluation of the impact of serogroup C meningococcal disease vaccination program in Brazil and its regions: a population-based study, 2001-2013

BACKGROUND Meningococcal C conjugate (MenC) vaccine was introduced as part of the Brazilian National Immunisation Program in 2010 for children < 1 year of age. OBJECTIVES The study objective was to evaluate the impact of this vaccination strategy. METHODS An observational, mixed ecological and analytical study was conducted, based on time series panel data from surveillance records (2001-2013). FINDINGS A total of 37,538 of meningococcal disease cases were recorded during the study period. Of these, 19,997 were attributed to serogroup C. A decrease in meningococcal disease serogroup C (MDC) incidence among children aged < 1 year [65.2%; 95% confidence interval (CI): 20.5-84.7%] and 1-4 years (46.9%; 95%CI: 14.6-79.1%) were found in the three years following vaccination introduction. Vaccination impact on the reduction of MDC incidence varied from 83.7% (95%CI: 51.1-100.0%) in the Midwest region to 56.7% (95%CI: 37.4-76.0%) in the Northeast region. MAIN CONCLUSIONS Vaccination against MDC in Brazil had a positive impact on the population of children aged < 1 year, across all regions, and on the 1-4 year-old cohort. Nevertheless, in our view there is scope for improving the vaccination strategy adopted in Brazil.

Nuevo esquema de vacuna antimeningocóccica en niños / New meningococcal vaccine schedule in children

La enfermedad invasiva por meningococo trae aparejada una alta morbimortalidad. Se presenta habitualmente en forma de casos aislados o brotes epidémicos y afecta en la Argentina a 200 a 300 casos por año, principalmente en niños menores de cinco años de edad. Actualmente en nuestro país se encuentran disponibles dos vacunas que cubren los serotipos A, C, Y, W del meningococo (Menactra® y Menveo®). A partir de Marzo de 2015, el Ministerio de Salud de la Nación Argentina incorporó la vacunación universal contra meningococo, estableciendo un esquema con una dosis a los tres y cinco meses y un refuerzo a los 15 meses de vida; y una dosis única para los adolescentes, a los 11 años de edad. (AU)

Invasive meningococcal disease results in high morbidity and mortality. It usually occurs in the form of isolated cases of epidemic outbreaks and affects 200 to 300 cases per year in Argentina, especially in children under five years of age. Vaccines covering meningococcal serotypes A, C, Y, W (Menactra® and Menveo®) are currently available in our country. Since March 2015, the Argentine's Ministry of Health incorporated the universal vaccination against meningococcus, establishing a scheme with two doses at three and five months and a booster at 15 months of life; and a single dose for adolescents, at 11 years of age. (AU)

Impacto da implantação da vacina conjugada na incidência de meningite meningocócica do tipo C em crianças menores de cinco anos no Sul de Santa Catarina / Impact of the conjugated vaccine implementation on the incidence of meningococcal meningitis type C in children under five in southern Santa Catarina

Introdução: A Doença Meningocócica (DM) é uma infecção bacteriana aguda causada pela Neisseria meningitidis. Acomete principalmente crianças menores de cinco anos, sobretudo as menores de um ano. Suas manifestações clínicas variam desde doença leve até síndrome séptica e/ou meningite. Diante da letalidade da doença, o Ministério da Saúde incluiu no calendário vacinal, no segundo semestre de 2010, a vacina adsorvida meningocócica C (conjugada). Justificativa: Considerando a recente implementação da vacina no serviço público, é necessário avaliar o impacto desta na saúde da população. Este estudo tem como objetivo descrever a ocorrência de Meningite Meningocócica do tipo C em crianças menores de cinco anos na macrorregional Sul do Estado de Santa Catarina dois anos antes (2008 e 2009) e dois anos depois (2011-2012) após a campanha vacinal contra o meningococo C, realizada no ano de 2010. Métodos: Este é um estudo observacional do tipo transversal. Resultados/Discussão: No período estudado, houve apenas cinco casos confirmados de doença meningocócica. O baixo número de casos deve-se provavelmente à ampla utilização da vacina em clínicas particulares já em anos anteriores aos estudados. Nenhuma criança morreu devido à meningite meningocócica ou meningococcemia, sendo que estudos no Brasil em períodos anteriores à vacinação mostraram letalidade em torno de 20%. Conclusão: O menor número de casos e menor mortalidade pela DM demonstram maior efetividade da Vigilância Epidemiológica e efetividade do diagnóstico precoce (AU)

Introduction: Meningococcal disease (MD) is an acute bacterial infection caused by Neisseria meningitidis. It mainly affects children under five years of age, especially children under one year. Its clinical manifestations range from mild disease to septic syndrome and/or meningitis. Given the lethality of the disease, the Ministry of Health included the adsorbed meningococcal C vaccine (conjugated) in the vaccine calendar in the second half of 2010. Justification: Considering the recent implementation of the vaccine in the public service, it is necessary to evaluate its impact on the health of the population. This study aims to describe the occurrence of Meningococcal Meningitis type C in children under five years of age in the southern macro-region of the State of Santa Catarina two years before (2008-2009) and two years after (2011-2012) the vaccination campaign against meningococcus C carried out in 2010. Methods: This is an observational cross-sectional study. Results/Discussion: In the study period, there were only five confirmed cases of meningococcal disease. The low number of cases is likely due to the wide use of the vaccine in private clinics already years before those studied here. No child died due to meningococcal meningitis, and studies in Brazil prior to vaccination show lethality around 20%. Conclusion: The lower number of cases and lower mortality due to MD demonstrate greater effectiveness of the Epidemiological Surveillance and the effectiveness of early diagnosis (AU)

Detección de Neisseria meningitidis en portadores asintomáticos en un hospital universitario de Brasil / Detectio of Neisseria meningitidis in asymptomatic carriers in a university hospital from Brazil

Los portadores asintomáticos de meningococos en hospitales son un factor de riesgo (FR) para adquirir la enfermedad meningocócica. La frecuencia de portadores de meningococos fue determinada a través de colecta orofaríngea en personal de un hospital de Brasil (n = 200). La prevalencia de portadores fue del 9% (IC del 95%, 5-13%). Los FR asociados al estado de portador fueron los siguientes: edad promedio 26,5 años, sexo masculino, hábito de frecuentar bares y número de personas/casa. Entre las 18 cepas de meningococos aisladas, 14 eran no agrupables (NG), 3 correspondieron al serogrupo B y una al 29E. La frecuencia de los serotipos y serosubtipos fue heterogénea, con un ligero predominio de los serotipos 4 y 7 y de los serosubtipos P1.7 y P1.5. La mayoría de las cepas (n=13) fueron sensibles a los antimicrobianos estudiados. El gen ctrA fue identificado por PCR en 9 (64,3%) de las 14 cepas NG, lo que sugiere virulencia en la mayoría de las cepas NG aisladas. Por lo tanto, se requiere una vigilancia constante de estos portadores asintomáticos

Asymptomatic meningococcus carriers in hospitals is a risk factor for acquiring meningococcal disease. Meningococcal carrier (MC) frequency was investigated in oropharyngeal swab samples collected from 200 staff members at a teaching hospital from Brazil. MC prevalence was 9% (95% CI 5­13%). Risk factors associated with MC were: mean age of 26.5 years, male gender, bar attendance frequency and number of persons/house. Of 18 isolated meningococcal strains, 14 were non-groupable (NG), 3 corrresponded to serogroup B and 1 to serogroup 29E. The frequency of serotypes and serosubtypes was heterogenous, with a slight predominance of serotypes 4 and 7 and serosubtypes P1.7 and P1.5. Most strains (n=13) were susceptible to the antimicrobials tested. The ctrA gene (PCR) was identified in 9 (64.3%) of the 14 NG strains, suggesting virulence in most of the NG isolated strains. Therefore, a constant surveillance of these asymptomatic carriers is required

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.

Efectividad de la vacuna antimeningocócica VA-MENGOC-BC® en el primer año de vida, Cuba, 1997-2008 / Effectiveness of the anti-meningococcal vaccine VA-MENGO-BC® in the first year of life of Cuban children, 1997-2008

Introducción: la enfermedad meningocócica constituye un importante problema de salud mundial. Desde 1991 la vacuna VA-MENGOC-BC® se aplica en Cuba a los niños menores de 1 año. Objetivo: evaluar la efectividad de la vacuna VA-MENGOC-BC®. Métodos: para la evaluación poslicenciamiento de VA-MENGOC-BC® se estudiaron los lactantes con enfermedad meningocócica notificados entre 1997 y 2008. Resultados: ocurrieron 114 casos para una incidencia media anual de 7,1/100 000 lactantes. La estimación de la efectividad vacunal media resultó de 84,0 por ciento, oscilando entre 68 y 104 por ciento. La ocurrencia de enfermedad meningocócica en los no vacunados fue de 20,2 por ciento (23/114); 79,8 por ciento (91/114) en lactantes con edad de vacunación y en 75,8 por ciento (69/91) se precisó la fecha de inmunización. Tenían una sola dosis de vacuna aplicada 26,4 por ciento (24/91) y 73,6 por ciento (67/91) recibió el esquema completo (2 dosis). La enfermedad meningocócica predominó en los primeros 6 meses de edad, declinó a partir de este momento y comenzó de nuevo su ascenso a los 10 y 11 meses. Predominó la forma meníngea (89,5 por ciento); la letalidad general fue de 7 por ciento (8/114), con 4,4 por ciento para la meningococemia y 2,6 por ciento para la meningitis. Conclusiones: la efectividad de VA-MENGOC-BC® fue satisfactoria. Se sugiere realizar un análisis por un grupo de expertos sobre la necesidad de aplicar una tercera dosis.

Introduction: meningococcal disease is an important health problem worldwide. Since 1991 the vaccine VA-MENGOC-BC has been used in Cuban under one-year old infants. Objective: to evaluate the effectiveness of the vaccine VA-MENGO-BC®. Methods: for the evaluation after licensing this vaccine, all the infants affected by meningococcal disease between 1997 and 2008 were studied. Results: a total number of 114 cases were recorded. The annual average incidence was 7.1 per 100 000 infants. The mean vaccinal effectiveness for the period was 84.0 percent, ranging from 68 percent to 104 percent. The frequency of disease in unvaccinated children was 20.2 percent (23/114); 79.8 percent (91/114) within the vaccination age, but only 75.8 percent (69/91) of them had confirmed the immunization date. Only 26.4 percent (24/91) had one single dose applied whereas 73.6 percent (67/91) had completed their vaccination schedule (2 doses). The meningococcal disease prevailed in the first six months of life, declined afterwards and then started to rise again at 10 and 11 months of age. The meningeal form of clinical presentation predominated (89.5 percent); case-fatality rate was 7.0 percent (8/114), being 4,4 percent for meningococcemia and 2,6 percent for meningitis. Conclusions: the vaccine VA-MENGOC-BC® effectiveness in infants was satisfactory. It is suggested that further analysis be made by a group of experts on the use of a booster dose.

Doença meningocócica / Meningococcal disease

Os autores fazem uma revisão bibliográfica atualizada sobre a etiologia, manifestações clínicas, diagnóstico, tratamento, prognóstico e prevenção da doença meningocócica

Pancreatectomía distal con conservación de bazo: aspectos técnicos y análisis de nuestra casuística / Distal pancreatectomy with spleen preservation: technique and the outcomes of our experience

Antecedentes: Clásicamente la esplenectomía ha formado parte de la pancreatectomía distal. El reconocimiento de la importancia de las funciones del bazo ha motivado el interés en la conservación del mismo. La pancreatectomía distal con conservación de bazo fue descripta por primera vez en 1943. Con la excepción de algunos casos reportados en la literatura internacional, no se ha implementado rutinariamente en cirugía electiva. En los últimos años, se observó un interés en su utilización para el tratamiento de lesiones benignas y de bajo grado de malignidad y se desarrolló la resección por vía laparoscópica. Objetivo: Revisión de la evolución técnica y de nuestra casuística. Población: Intentamos conservar el bazo en 25 pacientes con lesiones benignas entre 1993 y 2001. Método: Se realizó pancreatectomía distal con conservación de bazo y vasos esplénicos. El último caso se realizó por vía laparoscópica. Resultados: La preservación del bazo fue posible en 24 de los 25 pacientes y en 23 pudieron preservarse los vasos esplénicos. El tiempo operatorio promedio fue 195 minutos. Cinco pacientes presentaron complicaciones postoperatorias (21,7 por ciento). No hemos observado isquemia ni absceso de bazo en ésta serie. La estadía hospitalaria promedio fue de 8,3 días. El seguimiento postoperatorio varió entre 5 y 80 meses (promedio 40 meses), sin detectarse alteraciones hematológicas por asplenia. Un paciente desarrolló diabetes insulino-dependiente 6 años luego de la operación (4 por ciento) y no se observó ningún caso de alteración de la función exocrina del páncreas. Conclusiones: La pancreatectomía distal con conservación de bazo es una operación segura y eficaz. La preservación de los vasos esplénicos evita el desarrollo de abscesos del bazo. La sección pancreática previa a la disección retrógrada, descripta en éste traabajo, facilita la preservación de los vasos esplénicos. Esta técnica es reproducible mediante el abordaje laparoscópico

Doenças meningococicas: morbidade e epidemilogia nos ultimos 20 anos: revisão / Meningococcal diseases: morbidity and epidemilogu in the last 20 years: a review

Objetivo: analisar a morbidade e os dados epidemiologicos referentes as doencas meningococicas nas ultimas duas decadas. Fontes pesquisadoras: foram selecionados...

Effectiveness of a mass immunization campaign against serogroup C meningococci in children in the federal state of Santa Catarina, Brazil

In addition to vaccine efficacy studies, there is a pressing need to evaluate vaccine effectiveness in a way that takes into account the limitations of health care systems in certain settings. An attempt to reach this objective was exemplified by a vaccination campaign against serogroup C meningococci in the federal state of Santa Catarina, in Brazil. A polysaccharide vaccine against serogroup C meningococci was administered to all individuals between 6 months and 14 years of age in March, 1996, in the municipalities that had the highest incidence of meningococcal disease in the previous year. All cases of the disease due to this serogroup observed in Santa Catarina during a 1-year period before and after the vaccination were included in the analysis. The cumulative incidence rate ratio was calculated for the unvaccinated compared to the vaccinated area. As a second step, the ratio of this quantity for the period before and after the vaccination, i.e. the ratio of the rate ratios (RRR), was calculated. One minus RRR was used to estimate the vaccine effectiveness. In the general population, the vaccine effectiveness was 74.3 (95 confidence intervals 52.7 to 99.6). In children 6 months to 14 years, vaccine effectiveness was 93.1 (85.2 to 100). Vaccine effectiveness could not be confirmed within more specific age bands, probably due to the lack of statistical power. It is concluded that group C meningococcal vaccine is effective in reducing the occurrence of meningococcal disease in children 6 months to 14 years of age, and that the ratio of rate ratios (RRR) in a useful method to evaluate vaccine effectiveness.

Enfermedades transmisibles: recomendaciones para el manejo de los contactos epidemiológicos / Guidelines for the management of epidemiological contacts in communicable disease

Se presentan los principales conceptos epidemiológicos relativos a la transmisión de las enfermedades infecciosas transmisibles de importancias en Chile. Se proporciona en detalle las reconmedaciones para el control de su diseminación entre los contactos con una visión personal del autor en algunos casos

Vacinas antimeningocócicas / Anti-meningococcal vaccines

A doença meningocócica é um problema de saúde pública em todo mundo. Na maioria das vezes apresenta-se como meningite, uma condiçäo grave, que pode deixar sequelas nos sobreviventes. A quimioprofilaxia dos contactantes é eficaz na imensa maioria das vezes. As vacinas atuais säo elaboradas com polissacarídios capsulares dos meningococos dos sorogrupos A, C, Y e W-135. Já para o meningococo B ela é feita de antígenos näo capsulares. Recentemente, foram desenvolvidas vacinas polissacarídicas conjugadas com proteínas. Acredita-se que estas devem gerar uma resposta imune mais intensa e mais duradoura mesmo em lactentes.