Evaluation of Haemophilus influenzae type b carrier status among children 10 years after the introduction of Hib vaccine in Brazil

The aim of the present study was to assess the prevalence of Haemophilus influenzaetype b (Hib) nasopharyngeal (NP) colonisation among healthy children where Hib vaccination using a 3p+0 dosing schedule has been routinely administered for 10 years with sustained coverage (> 90%). NP swabs were collected from 2,558 children who had received the Hib vaccine, of whom 1,379 were 12-< 24 months (m) old and 1,179 were 48-< 60 m old. Hi strains were identified by molecular methods. Hi carriage prevalence was 45.1% (1,153/2,558) and the prevalence in the 12-< 24 m and 48-< 60 m age groups were 37.5% (517/1,379) and 53.9% (636/1,179), respectively. Hib was identified in 0.6% (16/2,558) of all children in the study, being 0.8% (11/1,379) and 0.4% (5/1,179) among the 12-< 24 m and 48-< 60 m age groups, respectively. The nonencapsulate Hi colonisation was 43% (n = 1,099) and was significantly more frequent at 48-< 60 m of age (51.6%, n = 608) compared with that at 12-< 24 m of age (35.6%, n = 491). The overall resistance rates to ampicillin and chloramphenicol were 16.5% and 3.7%, respectively; the co-resistance was detected in 2.6%. Our findings showed that the Hib carrier rate in healthy children under five years was very low after 10 years of the introduction of the Hib vaccine.

Incidência de meningite por Haemophilus influenzae no RS 1999-2010: impacto da cobertura vacinal / Incidence of meningitis caused by Haemophilus influenzae in the state of Rio Grande do Sul 1999-2010: impact of vaccination campaign

O objetivo deste artigo é analisar e verificar a situação epidemiológica das meningites causadas pelo agente Haemophilus influenzae tipo b nos últimos 10 anos no Rio Grande do Sul. Estudo retrospectivo, descritivo, utilizando o sistema de dados de notificação de meningites, e cobertura vacinal, armazenados em base on line Tabnet - Tabulação de dados Epidemiológicos - CEVS/SES/RS, abrangendo o período de 1999 a 2010. Foram utilizados casos notificados e confirmados, tendo como critério de seleção o ano de inicio dos sintomas, idade, diagnostico e evolução. Foi analisado o Estado do Rio Grande do Sul, representado por 19 coordenadorias de saúde. Comparações entre proporções foram avaliadas pelo teste de z. No RS foram notificados 3043 casos confirmados de meningite bacteriana, sendo 6,77% dos casos causados por H. influenzae. O coeficiente de incidência da meningite por H. influenzae, sem considerar faixa etária, caiu significativamente (95,6%) após 1999, assim como a mortalidade. Crianças menores de um ano continuam sendo as mais acometidas (52%), não havendo alteração na letalidade. Os resultados apresentados revelaram um impacto positivo das estratégias de vacinação contra Hib no Estado do Rio Grande do Sul nos últimos dez anos.

This article seeks to analyze and update the epidemiological situation of meningitis caused by Haemophilus influenzae type b in the past 10 years in the state of Rio Grande do Sul (RS). It is a retrospective, descriptive study, which used the data notification system of meningitis and vaccination campaign coverage, stored in the Epidemiological TABNET online database, for the period from 1999 to 2010. Cases notified and confirmed were used and the selection criteria were the year when the symptoms were detected, age, diagnosis, and evolution. Nineteen health centers in the state of Rio Grande do Sul were analyzed. The z-test was used to evaluate comparisons between the proportions. In the period studied, 3043 confirmed cases of bacterial meningitis were reported, of which 6.77% were caused by H. influenzae. The incidence and mortality rates of meningitis caused by H. influenzae, without taking age group into consideration, fell significantly (95.6%) after 1999. Children under one year old continue to be the most affected (52%), there being no change in lethality. The results presented revealed a positive impact of Hib vaccination strategies in the state of Rio Grande do Sul over the past ten years.

Streptomycin induced protein expression analysis in Mycobacterium tuberculosis by two-dimensional gel electrophoresis & mass spectrometry.

Background & objectives: The resistance of Mycobacterium tuberculosis to streptomycin, a core drug for treatment of category II tuberculosis (TB) has posed a major challenge to the health providers as well as research workers worldwide and has severely compromised the therapeutic options. A significant proportion of streptomycin resistant M. tuberculosis isolates failed to show mutations in conventional targets like rpsL and rrs. Although efflux, permeability, etc. are also known to contribute, yet a substantial proportion of isolates remains resistant suggesting involvement of other unknown mechanism. A resistant isolate may show altered gene as well as protein expression under drug induced conditions and a whole cell proteome analysis under induced conditions might help in further understanding the mechanisms of drug resistance. The present study was therefore designed with the objective to identify proteins related to streptomycin resistance in M. tuberculosis isolate grown in presence and absence of streptomycin (SM). Methods: A clinical isolate of M. tuberculosis from Mycobacterial Repository Centre at the Institute (NJIL & OMD), Agra was grown in Sauton’s medium for 36 h with/without subinhibitory concentration of the drug (2 μg/ml) and the cell lysate of isolates was prepared by sonication and centrifugation. Two-dimensional (2D) gel electrophoresis was employed to study the protein profile. The selected proteins were finally identified by MALDI-TOF mass spectrometry. Results: Our study revealed eight inducible proteins (DnaK, fabG4, DNA-binding, hypothetical, two 14 kDa antigen and two 10 kDa chaperonin) that were upregulated in the presence of drug. Interpretation & conclusion: This preliminary study has thrown light on whether or not and how the resistant isolate responds to streptomycin at its non-toxic but sub-inhibitory concentration. An in-depth study of the upregulated proteins will give an insight into probable sites of drug action other than established primary sites.

Vacinação contra Haemophilus influenzae tipo b: proteção a longo prazo / Haemophilus influenzae type b vaccination: long term protection

OBJETIVO: Identificar as evidências sobre o impacto da vacina conjugada para Haemophilus influenzae tipo b (Hib) na epidemiologia da doença invasiva por Hib. FONTE DOS DADOS: Pesquisa nas bases de dados do MEDLINE, LILACS, publicações técnicas de organizações internacionais, diretrizes nacionais e internacionais, nos últimos 15 anos (1991-2005), utilizando os seguintes unitermos: Haemophilus influenzae type b, immunization, impact, effectiveness. Foram incluídas as publicações que apresentaram informação para atender o objetivo deste artigo. Artigos publicados em período anterior ao da pesquisa e citados em referências dos artigos incluídos foram analisados quanto à apresentação de informação de interesse. SíNTESE DOS DADOS: A introdução da vacina conjugada para Hib produziu grande declínio na incidência de casos de doença invasiva por Hib nos diversos países em que seu uso foi incorporado à rotina de vacinação das crianças. No entanto, o ressurgimento de casos com doença invasiva por Hib tem mobilizado vários investigadores na busca das possíveis explicações para esses eventos, bem como a identificação das medidas a serem implementadas para evitar o reaparecimento da doença. CONCLUSÕES: O uso da vacina conjugada para Hib em escala populacional tem sido extremamente efetivo. No entanto, mudanças no esquema vacinal poderão ser necessárias para a manutenção do controle da doença invasiva por Hib, frente ao atual cenário epidemiológico das infecções pelo Hib.

Infecciones invasoras por Haemophilus influenzae tipo b después de la incorporación de la vacuna conjugada al Programa Ampliado de Inmunizaciones en Chile / Invasive infections caused by Haemophilus influenzae type b after the institution of the conjugated vaccine on the Expanded Programm on Immunization in Chile

Tras nueve años desde la introducción en Chile de la vacuna conjugada contra Haemophilus influenzae tipo b (Hib) a las edades de 2-4 y 6 meses, las infecciones por este agente han disminuido notoriamente, pero aún son causa de morbilidad de importancia en algunos pacientes. Se reportan los niños con enfermedad invasora por Hib ocurridas entre los años 2000 y 2004. Para esto se analizaron los egresos del Hospital Padre Hurtado, consignándose epidemiología, clínica, laboratorio, terapia y complicaciones para cada paciente. Durante este período, 23 pacientes (17 varones), con una mediana de edad de 30 meses (rango 1-71 meses) presentaron enfermedad invasora por Hib. Estas se presentaron como neumonía (7), meningitis (4), pleuroneumonía (2), empiema pleural (2), sepsis (2), celulitis (2), meningitis y pleuroneumonía (1), purpura fulminans (1), miositis (1) y epiglotitis (1). No se registraron fallecimientos, pero 4 pacientes presentaron secuelas graves al momento del alta. Veinte pacientes fueron catalogados como falla de vacuna. Hamophilus influenzae b es aún un agente causal de enfermedad grave y con morbilidad asociada en nuestro país, por lo que es importante tener un alto índice de sospecha. Su estudio y notificación son relevantes para la evaluación del esquema de vacunación anti-Hib actualmente utilizado.

Epidemiology of haemophilus influenzae invasive disease in Jamaica, 1990-1993

Haemophilus influenzae (H influenzae) invasive disease was studied retrospectively over a four-year period in children admitted to the Bustamante Hospital for Children in Kingston, Jamaica. A total of 86cases were identified. The mean estimated annual incidence of H influenzae invasive disease in Kingston and St. Andrew was 39 per 100,000 children under 5 years of age. The majority (77percent) of cases were in the under 2-year age group. A distinct seasonal pattern was noted, with a significantly higher proportion of patients (57-73percent) presenting in the cooler months. Meningitis was the most common clinical diagnosis, accounting for 76percent of the cases. Poor outcome was demonstrated in 21.5percent of patients with meningitis. Sensitivity testing of H influenzae isolates revealed a resistance rate of 26percent for ampicillin and 7percent for chloramphenicol. The epidemiological findings in this study provide reasonable guidelines for empiric antibiotic therapy and also support the need to seriously consider vaccine prophylaxis in Jamaican children.

Meningitis aguda supurada: uso de nuevas vacunas / Acute suppurative meningitis: uses of new vaccines

Se analiza la situación de las infecciones por meningococo, neumococo y Haemophilus influenzae tipo b en el país, y los resultados insatisfactorios del tratamiento curativo, justificando el interés por las vacunas como el medio más efectivo de disminuir la morbilidad y proteger a los grupos de mayor riesgo. Una revisión del estado actual de las vacunas disponibles sustenta la conveniencia de la inmunización anti-haemophilus influenzae b, avalada tras 9 años de experiencia controladas como el medio de erradicar esa infección y apoya la necesidad de mejorar las vacunas antineumocócicas y antimeningocócicas B y someterlas a adecuados controles de eficacia