Streptococcus suis de type 2 est un microorganisme pathogène d’importance chez le porc. Il est la cause de différentes pathologies ayant comme caractéristique commune la méningite. C’est également un agent émergeant de zoonose : des cas cliniques humains ont récemment été rapportés en Asie. Cependant, la pathogénèse de S. suis n’est pas encore complètement élucidée. Jusqu’à présent, la réponse pro-inflammatoire initiée par S. suis n’a été étudiée qu’in vitro. L’étude du choc septique et de la méningite requiert toujours des modèles expérimentaux appropriés. Au cours de cette étude, nous avons développé un modèle in vivo d’infection chez la souris qui utilise la voie d’inoculation intra-péritonéale. Ce modèle a servi à l’étude de la réponse pro-inflammatoire associée à ce pathogène, tant au niveau systémique qu’au niveau du système nerveux central (SNC). Il nous a également permis de déterminer si la sensibilité aux infections à S. suis pouvait être influencée par des prédispositions génétiques de l’hôte. Le modèle d’infection par S. suis a été mis au point sur des souris de lignée CD1. Les résultats ont démontré une bactériémie élevée pendant les trois jours suivant l’infection. Celle-ci était accompagnée d’une libération rapide et importante de différentes cytokines pro-inflammatoires (TNF-α, IL-6, IL-12p40/p70, IFN-ɣ) et de chémokines (KC, MCP-1 and RANTES), qui ont entraîné un choc septique et la mort de 20 % des animaux. Ensuite, pour confirmer le rôle de l’inflammation sur la mortalité et pour déterminer si les caractéristiques génétiques de l’hôte pouvaient influencer la réponse inflammatoire et l’issue de la maladie, le modèle d’infection a été étendu à deux lignées murines consanguines différentes considérées comme résistante : la lignée C57BL/6 (B6), et sensible : la lignée A/J. Les résultats ont démontré une importante différence de sensibilité entre les souris A/J et les souris B6, avec un taux de mortalité atteignant 100 % à 20 h post-infection (p.i.) pour la première lignée et de seulement 16 % à 36 h p.i. pour la seconde. La quantité de bactéries dans le sang et dans les organes internes était similaire pour les deux lignées. Donc, tout comme dans la lignée CD1, la bactériémie ne semblait pas être liée à la mort des souris. La différence entre les taux de mortalité a été attribuée à un choc septique non contrôlé chez les souris A/J infectées par S. suis. Les souris A/J présentaient des taux exceptionnellement élevés de TNF-α, IL-12p40/p70, IL-1β and IFN- γ, significativement supérieurs à ceux retrouvés dans la lignée B6. Par contre, les niveaux de chémokines étaient similaires entre les lignées, ce qui suggère que leur influence est limitée dans le développement du choc septique dû à S. suis. Les souris B6 avaient une production plus élevée d’IL-10, une cytokine anti-inflammatoire, ce qui suppose que la cascade cytokinaire pro-inflammatoire était mieux contrôlée, entraînant un meilleur taux de survie. Le rôle bénéfique potentiel de l’IL-10 chez les souris infectées par S. suis a été confirmé par deux approches : d’une part en bloquant chez les souris B6 le récepteur cellulaire à l’IL-10 (IL-10R) par un anticorps monoclonal anti-IL-10R de souris et d’autre part en complémentant les souris A/J avec de l’IL-10 de souris recombinante. Les souris B6 ayant reçu le anticorps monoclonal anti-IL-10R avant d’être infectées par S. suis ont développé des signes cliniques aigus similaires à ceux observés chez les souris A/J, avec une mortalité rapide et élevée et des taux de TNF-α plus élevés que les souris infectées non traitées. Chez les souris A/J infectées par S. suis, le traitement avec l’IL-10 de souris recombinante a significativement retardé l’apparition du choc septique. Ces résultats montrent que la survie au choc septique dû à S. suis implique un contrôle très précis des mécanismes pro- et anti-inflammatoires et que la réponse anti-inflammatoire doit être activée simultanément ou très rapidement après le début de la réponse pro-inflammatoire. Grâce à ces expériences, nous avons donc fait un premier pas dans l’identification de gènes associés à la résistance envers S. suis chez l’hôte. Une des réussites les plus importantes du modèle d’infection de la souris décrit dans ce projet est le fait que les souris CD1 ayant survécu à la septicémie présentaient dès 4 jours p.i. des signes cliniques neurologiques clairs et un syndrome vestibulaire relativement similaires à ceux observés lors de méningite à S. suis chez le porc et chez l’homme. L’analyse par hybridation in situ combinée à de l’immunohistochimie des cerveaux des souris CD1 infectées a montré que la réponse inflammatoire du SNC débutait avec une augmentation significative de la transcription du Toll-like receptor (TLR)2 et du CD14 dans les microvaisseaux cérébraux et dans les plexus choroïdes, ce qui suggère que S. suis pourrait se servir de ces structures comme portes d’entrée vers le cerveau. Aussi, le NF-κB (suivi par le système rapporteur de l’activation transcriptionnelle de IκBα), le TNF-α, l’IL-1β et le MCP-1 ont été activés, principalement dans des cellules identifiées comme de la microglie et dans une moindre mesure comme des astrocytes. Cette activation a également été observée dans différentes structures du cerveau, principalement le cortex cérébral, le corps calleux, l’hippocampe, les plexus choroïdes, le thalamus, l’hypothalamus et les méninges. Partout, cette réaction pro-inflammatoire était accompagnée de zones extensives d’inflammation et de nécrose, de démyélinisation sévère et de la présence d’antigènes de S. suis dans la microglie. Nous avons mené ensuite des études in vitro pour mieux comprendre l’interaction entre S. suis et la microglie. Pour cela, nous avons infecté des cellules microgliales de souris avec la souche sauvage virulente (WT) de S. suis, ainsi qu’avec deux mutants isogéniques, un pour la capsule (CPS) et un autre pour la production d’hémolysine (suilysine). Nos résultats ont montré que la capsule était un important mécanisme de résistance à la phagocytose pour S. suis et qu’elle modulait la réponse inflammatoire, en dissimulant les composants pro-inflammatoires de la paroi bactérienne. Par contre, l’absence d’hémolysine, qui est un facteur cytotoxique potentiel, n’a pas eu d’impact majeur sur l’interaction de S. suis avec la microglie. Ces études sur les cellules microgliales ont permis de confirmer les résultats obtenus précédemment in vivo. La souche WT a induit une régulation à la hausse du TLR2 ainsi que la production de plusieurs médiateurs pro-inflammatoires, dont le TNF-α et le MCP-1. S. suis a induit la translocation du NF-kB. Cet effet était plus rapide dans les cellules stimulées par le mutant déficient en CPS, ce qui suggère que les composants de la paroi cellulaire représentent de puissants inducteurs du NF-kB. De plus, la souche S. suis WT a stimulé l’expression de la phosphotyrosine, de la PKC et de différentes cascades liées à l’enzyme mitogen-activated protein kinase (MAPK). Cependant, les cellules microgliales infectées par le mutant déficient en CPS ont montré des profils de phosphorylation plus forts et plus soutenus que celles infectées par le WT. Finalement, la capsule a aussi modulé l’expression de l’oxyde nitrique synthétase inductible (iNOS) induite par S. suis et par la production subséquente d’oxyde nitrique par la microglie. Ceci pourrait être lié in vivo à la neurotoxicité et à la vasodilatation. Nous pensons que ces résultats contribueront à une meilleure compréhension des mécanismes sous-tendant l’induction de l’inflammation par S. suis, ce qui devrait permettre, d’établir éventuellement des stratégies plus efficaces de lutte contre la septicémie et la méningite. Enfin, nous pensons que ce modèle expérimental d’infection chez la souris pourra être utilisé dans l’étude de la pathogénèse d’autres bactéries ayant le SNC pour cible. / Streptococcus suis serotype 2 is an important swine pathogen responsible for diverse infections, meningitis being its most striking feature. In addition, it is an emerging agent of zoonosis, which has gained worldwide attention due to important outbreaks in Asia. Understanding the pathogenesis of S. suis infections still represents a challenge. Up to present, the pro-inflammatory response due to S. suis has only been studied in vitro, and there is still a great need of appropriate experimental models for both septic shock and meningitis. In the present study, we successfully developed an in vivo model of S. suis infection in adult mice infected by the intraperitoneal route. This model served to investigate the pro-inflammatory events that take place at both the systemic and Central Nervous System (CNS) levels associated with this important pathogen. In addition, this model was useful to determine if susceptibility to S. suis infection may be influenced by the genetic background of the host. The mouse model of S. suis infection was standardized in CD1 mice. Results showed sustained bacteremia during the 3 days post-infection (p.i.), accompanied by a quick and substantial release of different pro-inflammatory cytokines (TNF-α, IL-6, IL-12p40/p70, IFN-ɣ) and chemokines (KC, MCP-1 and RANTES) that lead to septic shock and 20% mortality in mice. Once the hallmark of the septic phase of S. suis infection was established in CD1 mice, research continued with the objective to confirm the role of inflammation in mortality and to determine if the genetic background of the host may influence the inflammatory response toward this pathogen and the further outcome of the disease. For this, the mouse model of S. suis infection was used with two genetically different inbred mouse strains, this is, C57BL/6 (B6) and A/J mice, which are considered as the prototype of Th1-type and Th2-type mice, respectively. Results demonstrated a striking susceptibility to S. suis infection in A/J mice in comparison to B6 mice, with 100% mortality in the former mice strain at 20 h p.i., and 16 % mortality at 36 h p.i. for the latter. Very interestingly, and similarly to CD1 mice, bacteremia did not seem to be responsible for the death of mice, as both mice strains presented similar amounts of bacteria in blood and organs. Thus, it was postulated that the higher mortality in S. suis-infected A/J mice was due to uncontrolled septic shock. In fact, A/J mice presented very high levels of TNF-α, IL-12p40/p70, IL-1β and IFN-ɣ, that significantly exceeded those found in B6 mice. Remarkably, chemokine levels were similar between strains, suggesting their limited participation in the development of septic shock by S. suis. A greater survival of B6 mice was partially related to a better regulation of the pro-inflammatory cytokine cascade, as they showed a higher production of the anti-inflammatory cytokine IL-10 than A/J mice. The potential beneficial role of the IL-10 in mice infected with S. suis was confirmed using two approaches: the first, by blockage of the cell receptor of IL-10 (IL-10R) with an anti-mouse IL-10R monoclonal antibody (Mab) in B6 mice and the second by administrating recombinant mouse (rm)IL-10 (rmIL-10) to A/J mice. B6 mice that received the IL-10R MAb treatment before challenge with S. suis developed a clinical acute disease similar to that observed with A/J mice, with a striking and rapid increase in mortality and higher levels of TNF-α in comparison to those of infected mice that did not receive the treatment. Controversially, treatment with rmIL-10 significantly delayed the onset of septic shock in A/J mice infected with S. suis. These results show that survival from S. suis septic shock requires a tight regulation of pro- and anti-inflammatory mechanisms, and that the latter should be activated at the same time or soon after the onset of the pro-inflammatory response. This part of the study may represent a first step in the identification of host genes associated with resistance against S. suis. One of the most important achievements of the mouse model of infection described in this project is the development of distinct clinical signs of neurological disease in CD1 mice from 4 days p.i. Indeed, in CD1 mice that survived sepsis due to S. suis infection, clinical signs of neurological disease and vestibular syndrome, which are quite similar to those observed in clinical cases of S. suis meningitis in both pigs and humans, were observed. Studies of the brains of infected CD1 mice using in situ hybridization combined with immunocytochemistry, demonstrated that the CNS inflammatory response began with a significant increase in the transcription of Toll-like receptor (TLR)2 and CD14 initially in the brain microvasculature and choroid plexuses, suggesting that S. suis may use these structures as portals of entry to the brain. There also was activation of NF-κB (as indicated by transcriptional activation of IκBα as a reporter system) and TNF-α, IL-1β and MCP-1, mainly in cells identified as microglia and to a lesser extent in astrocytes. These signals reached different brain structures, mainly the brain cortex, corpus callosum, hippocampus, choroid plexuses, thalamus, hypothalamus and meninges. All of these pro-inflammatory events were associated with extensive areas of inflammation and necrosis, severe demyelination and presence of antigens of S. suis inside microglia. In vitro studies were conducted in order to better understand the interactions of S. suis and microglia. For this, mouse microglia were infected with a virulent wild type (WT) strain of S. suis. Two isogenic mutants deficient in capsule (CPS) or hemolysin production (suilysin, SLY) respectively, were also included for comparative purposes. The CPS was important for S. suis resistance to phagocytosis, and it also modulated the inflammatory response by hiding pro-inflammatory components from the bacterial cell wall. On the other hand, the absence of SLY, a potential cytotoxic factor, did not have a major impact on S. suis interactions with microglia. Studies with microglia helped to confirm previous findings in vivo in mice, as the WT S. suis strain induced the up-regulation of TLR2 and the production of several pro-inflammatory mediators, including TNF-α and MCP-1. As observed in mice, S. suis induced NF-kB translocation, which was more rapid for cells stimulated with the CPS-deficient mutant, suggesting that bacterial cell wall components are potent inducers of NF-kB. Moreover, WT S. suis promoted phosphotyrosine, PKC and different mitogen-activated protein kinase (MAPK) events. However, microglia infected with the CPS-deficient mutant showed overall stronger and more sustained phosphorylation profiles. Finally, the CPS also modulated S. suis-induced inducible nitrogen oxide synthase (iNOS) expression and further nitric oxide production in microglia, which could be related to neurotoxicity and vasodilatation in vivo. We are confident that our results may help to more fully understand the mechanisms underlying S. suis induction of inflammation, leading to the design of more efficient anti-inflammatory strategies for sepsis and meningitis. Finally, we believe this experimental model of infection in mice could also be useful for studying the pathogenesis of infections of the CNS, due to other bacteria.

INTRODUÇÃO: A vacina pneumocócica conjugada 10-valente (VPC10) foi introduzida no calendário de imunização infantil do Programa Nacional de Imunizações em 2010. Este estudo analisou as taxas de incidência de Meningite Pneumocócica (MP) no Brasil, por faixa etária e unidade da federação (UF); a distribuição espacial das taxas de incidência de MP em menores de cinco anos no Brasil, por UF, no período pré (2005-2009) e pós-vacinação (2011-2013); e associações com variáveis socioeconômicas e cobertura vacinal. Foram analisadas a distribuição espacial das taxas de incidência de MP em menores de cinco anos, por município do estado de São Paulo (SP), no período pré e pós-vacinação, e a existência de aglomerados espaciais e espaço-temporais. Através de estatística espacial, foram analisadas associações das taxas de incidência de MP, por microrregiões do estado, com variáveis socioeconômicas e cobertura vacinal. MÉTODOS: Estudo ecológico de base populacional, que utilizou dados do Sistema de Informação de Agravos de Notificação. Cobertura vacinal e o Índice de Desenvolvimento Humano (IDH) foram utilizados na análise do Brasil. Na análise de SP, as unidades ecológicas foram municípios e microrregiões, e a variável socioeconômica foi o Índice Paulista de Responsabilidade Social (IPRS) da Fundação Sistema Estadual de Análise de Dados. Foram construídos mapas temáticos para as taxas de incidência de MP em menores de cinco anos, nos períodos pré e pós vacinação, cobertura vacinal e IDH, por UF. Também foram construídos mapas temáticos das taxas de incidência de MP em menores de cinco anos, por microrregião de SP, nos períodos pré e pós-vacinação, cobertura vacinal e IPRS, utilizando o software QGis 2.6.1. Para SP, foi utilizada a técnica de varredura (software SatScan 9.2) para analisar aglomerados. O modelo Gaussiano latente Bayesiano com modelos inflados de zeros de Poisson, através da aproximação de Laplace aninhada e integrada (INLA), foi utilizado na análise espacial para avaliar associações entre taxa de incidência de MP, cobertura vacinal e variáveis socioeconômicas. RESULTADOS: De 2005 a 2013, foram notificados 10.769 casos de MP. Crianças menores de cinco anos foram as mais acometidas. No período pós-vacinação (2011-2013), a taxa de incidência de MP diminuiu nos menores de cinco anos, especialmente nos menores de um ano (de 10,42/100.000, em 2005, para 4,13/100.000, em 2013). No Brasil, maiores taxas de incidência de MP ocorreram nos estados com maior IDH. Em SP ocorreu o mesmo, sendo encontrados, no período pré-vacinação, dois aglomerados de municípios - um de baixo risco para MP, no noroeste do estado (RR, 0,45, p=0,00025), e outro de alto risco no sudeste, englobando a capital do estado, (RR, 1,62, p=0,0000051). No período pós-vacinação, apenas um aglomerado de maior risco se manteve na mesma região (RR, 1,97, p=0,057). Na análise Bayesiana, riqueza foi identificada como fator de risco para MP (RR, 1,026, IC: 1,002-1,052) no período pré-vacinação. Cobertura vacinal, longevidade e escolaridade não foram significativas. CONCLUSÕES: Maior IDH e maior riqueza foram fatores de risco para MP, sugerindo necessidade de maior investimento na capacidade diagnóstica de MP nas áreas estudadas, avanços na qualificação da vigilância e notificação da doença / INTRODUCTION: The 10-Valent pneumococcal conjugate vaccine (PCV10) was introduced into the childhood immunization schedule of the Brazilian National Immunization Program in 2010. This study analyzed Pneumococcal Meningitis (PM) incidence rates in Brazil, by age group and federation unit (FU), the spatial distribution of PM incidence rates in under-5 children in Brazil, by FU, in the pre (2005-2009) and post-vaccination (2011-2013) periods, and associations with socioeconomic variables and vaccination coverage. We conducted spatial analysis of PM incidence rates in under-5 children, by municipality in SP, in pre and post-vaccination periods, and evaluated the existence of spatial and spatial-temporal clusters. Spatial statistics was used to test associations of PM incidence rates with socioeconomic variables and vaccine coverage, by state micro regions. METHODS: This is a population-based ecological study using data from the Sistema de Informação de Agravos de Notificação. Vaccine coverage and the Human Development Index (HDI) were used in the Brazilian analysis. In SP analysis, the ecological units were municipalities and micro regions, and the socio-economic variable was the Índice Paulista de Responsabilidade Social (IPRS) of the Fundação Sistema Estadual de Análise de Dados. Thematic maps were built for PM incidence rates in under-5 children, in the pre- and post-vaccination periods, vaccine coverage and HDI, by FU. Thematic maps were also built for PM incidence rates in under-5 children by SP micro regions, in the pre- and post-vaccination periods, vaccination coverage and IPRS using QGis 2.6.1 software. The scanning technique (SatScan 9.2 software) was used to analyze spatial and spatiotemporal clusters in SP. A Bayesian latent Gaussian model with zero-inflated Poisson model through the integrated nested Laplace approximation (INLA) was used in the spatial analysis to evaluate associations of PM incidence rates with vaccine coverage and socioeconomic variables. RESULTS: From 2005 to 2013, 10,769 PM cases were reported. Under-5 children were the most affected in the whole period. In the post-vaccination period (2011-2013), PM incidence rates decreased among under-5 children, especially among infants (from 10.42/100,000, in 2005, to 4.13/100,000, in 2013). Higher PM incidence rates occurred in states with higher HDI. The same occurred in SP, where two municipalities clusters were found in the pre-vaccination period - one of low risk for PM in the northwest of the state (OR, 0.45, p=0.00025), and another of high risk in the southeast, including the state capital (OR, 1.62, p=0.0000051). In the post-vaccination period, only one cluster of higher risk remained in the same area (RR, 1.97, p=0.057). In Bayesian analysis, wealth was identified as a risk factor for PM (RR, 1.026, CI: 1.002-1.052). Vaccination coverage, longevity and education were not important. CONCLUSIONS: A higher HDI as well as greater wealth were risk factors for PM. This result highlights the need to improve the diagnostic capacity of PM in studied areas, advancing in the surveillance quality and disease notification

A meningite bacteriana no período neonatal é uma doença grave, associada à mortalidade elevada e seqüelas em cerca de 12 a 29% dos sobreviventes. Nos recém-nascidos com peso ao nascimento < 2500 g, o risco de adquirir meningite é três vezes superior àqueles com peso >= 2500 g e, entre neonatos de muito baixo peso (< 1500 g), o risco é 17 vezes maior. Objetivo: Geral: descrever o quadro clínico e as complicações da meningite bacteriana em dois grupos de recém-nascidos, considerados de acordo com o peso de nascimento (= 2500 g). Específico: descrever e comparar os agentes etiológicos, a freqüência de sinais e sintomas neurológicos e de complicações, a mortalidade e a duração do tratamento nos dois grupos. Métodos: Estudo observacional de 87 recém-nascidos com meningite bacteriana, admitidos na Unidade de Cuidados Intensivos Neonatais do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, no período de 11 anos (janeiro de 1994 a dezembro de 2004). Os dados foram obtidos através da análise de prontuários. Na análise estatística foram utilizados o teste exato de Fisher e teste não paramétrico de Mann Whitney. Resultados: Foram identificadas bactérias no líquor em 39% dos pacientes, sendo 50% bactérias Gram-positivas e 50% Gram-negativas. A maioria dos neonatos apresentou sinais e sintomas inespecíficos: febre (63,2%), irritabilidade (31%), letargia (26,4%). Os achados neurológicos ocorreram em 35,3% dos casos. As complicações ocorreram em 48,2% dos neonatos, principalmente convulsões (23%), hemorragia intracraniana (14,9%) e hidrocefalia (13,8%) com mortalidade de 11,5 %. Na comparação entre evolução clínica e peso de nascimento observou-se associação entre peso >= 2500 g e convulsão (p=0,047), peso >= 2500 g e fontanela abaulada (p=0,019), bactéria no LCR e complicações (p=0,008) e bactéria no LCR e óbitos (p=0,043). Conclusões: Os agentes etiológicos mais freqüentemente identificados no LCR foram as enterobactérias (41%), seguidas de Streptococcus B (17,5%), Streptococcus não B (17,5%), Staphylococcus aureus (11,7%), Neisseria meningitidis (8,8%) e Enterococcus faecalis (3,0%), não havendo diferença entre tipo de bactérias e peso de nascimento. Os sinais e sintomas predominantes foram inespecíficos, com achados neurológicos em 35% dos casos. A freqüência maior de sintomas neurológicos nos recém-nascidos com peso >= 2500 g, sugere maior grau de maturidade do sistema nervoso central nestas crianças. Embora a mortalidade tenha sido inferior à observada em estudos anteriores no mesmo Serviço, a freqüência de complicações foi alta, independentemente do peso de nascimento. A presença de bactéria no LCR associou-se à maior freqüência de convulsões e mortalidade. A necessidade de manutenção do tratamento por tempo mais prolongado nos recém-nascidos de baixo peso sugere maior gravidade da doença neste grupo de neonatos. / Bacterial meningitis in the neonatal period is a severe disease, associated to elevated mortality and sequelae in around 12 to 29% of the survivors. Newborns whose birth weight is < 2,500g have a 3-fold increase in the risk of acquiring meningitis when compared to those whose weight is >= 2,500; among those with very low birth weight (< 1,500g), the risk increases 17-fold. Objectives: General: to describe the clinical picture and the complications of bacterial meningitis in two groups of newborns, considered according to birth weight (< 2,500g or >= 2,500g). Specific: to describe and compare the etiological agents, the frequency of neurological signs and symptoms and complications, mortality rate and duration of treatment in both groups. Methods: Observational study of 87 newborns with bacterial meningitis, admitted at the Neonatal Intensive Care Unit (NICU) of Instituto da Criança of Hospital das Clínicas of the University of São Paulo School of Medicine, during an 11-year period (January 1994 to December 2004). The data were obtained through the analysis of hospital files. Statistical analysis was carried out with Fisher\'s exact test and the non-parametric Mann Whitney test. Results: Bacteria were identified in the cerebrospinal fluid (CSF) of 39% of the patients, with 50% of them being Gram-positive and 50%, Gram-negative. Most neonates presented unspecific signs and symptoms: fever (63.2%), irritability (31%), and lethargy (26.4%). The neurological findings occurred in 35.3% of the cases. Complications occurred in 48.2% of the neonates, and were mainly seizures (23%), intracranial hemorrhage (14.9%) and hydrocephalus (13.8%) with a mortality rate of 11.5%. At the comparison between clinical evolution and birth weight, associations between weight >= 2,500g and seizures (p=0.047), weight >= 2,500g and concave fontanel (p=0.019), bacteria in the CSF and complications (p=0.008) and bacteria in the CSF and death (p=0.043) were observed. Conclusions: The etiological agents most often identified in the CSF were enterobacteria (41%), followed by B Streptococcus (17.5%), non-B Streptococcus (17.5%), Staphylococcus aureus (11.7%), Neisseria meningitidis (8.8%) and Enterococcus faecalis(3.0%), with no statistical difference between the type of bacteria and birth weight. The predominant signs and symptoms were unspecific, with neurological findings in 35% of the cases. The higher frequency of neurological signs and symptoms in newborns with birth weight >= 2,500g suggest a higher degree of central nervous system maturity in these infants. Although the mortality was lower than that observed in previous studies at the same Service, the frequency of complications was high, regardless of birth weight. The presence of bacteria in the CSF was associated to a higher frequency of seizures and mortality. The need for prolonged treatment in newborns with low birth weight suggests higher disease severity in this group of neonates.

INTRODUÇÃO: A vacina pneumocócica conjugada 10-valente (VPC10) foi introduzida no calendário de imunização infantil do Programa Nacional de Imunizações em 2010. Este estudo analisou as taxas de incidência de Meningite Pneumocócica (MP) no Brasil, por faixa etária e unidade da federação (UF); a distribuição espacial das taxas de incidência de MP em menores de cinco anos no Brasil, por UF, no período pré (2005-2009) e pós-vacinação (2011-2013); e associações com variáveis socioeconômicas e cobertura vacinal. Foram analisadas a distribuição espacial das taxas de incidência de MP em menores de cinco anos, por município do estado de São Paulo (SP), no período pré e pós-vacinação, e a existência de aglomerados espaciais e espaço-temporais. Através de estatística espacial, foram analisadas associações das taxas de incidência de MP, por microrregiões do estado, com variáveis socioeconômicas e cobertura vacinal. MÉTODOS: Estudo ecológico de base populacional, que utilizou dados do Sistema de Informação de Agravos de Notificação. Cobertura vacinal e o Índice de Desenvolvimento Humano (IDH) foram utilizados na análise do Brasil. Na análise de SP, as unidades ecológicas foram municípios e microrregiões, e a variável socioeconômica foi o Índice Paulista de Responsabilidade Social (IPRS) da Fundação Sistema Estadual de Análise de Dados. Foram construídos mapas temáticos para as taxas de incidência de MP em menores de cinco anos, nos períodos pré e pós vacinação, cobertura vacinal e IDH, por UF. Também foram construídos mapas temáticos das taxas de incidência de MP em menores de cinco anos, por microrregião de SP, nos períodos pré e pós-vacinação, cobertura vacinal e IPRS, utilizando o software QGis 2.6.1. Para SP, foi utilizada a técnica de varredura (software SatScan 9.2) para analisar aglomerados. O modelo Gaussiano latente Bayesiano com modelos inflados de zeros de Poisson, através da aproximação de Laplace aninhada e integrada (INLA), foi utilizado na análise espacial para avaliar associações entre taxa de incidência de MP, cobertura vacinal e variáveis socioeconômicas. RESULTADOS: De 2005 a 2013, foram notificados 10.769 casos de MP. Crianças menores de cinco anos foram as mais acometidas. No período pós-vacinação (2011-2013), a taxa de incidência de MP diminuiu nos menores de cinco anos, especialmente nos menores de um ano (de 10,42/100.000, em 2005, para 4,13/100.000, em 2013). No Brasil, maiores taxas de incidência de MP ocorreram nos estados com maior IDH. Em SP ocorreu o mesmo, sendo encontrados, no período pré-vacinação, dois aglomerados de municípios - um de baixo risco para MP, no noroeste do estado (RR, 0,45, p=0,00025), e outro de alto risco no sudeste, englobando a capital do estado, (RR, 1,62, p=0,0000051). No período pós-vacinação, apenas um aglomerado de maior risco se manteve na mesma região (RR, 1,97, p=0,057). Na análise Bayesiana, riqueza foi identificada como fator de risco para MP (RR, 1,026, IC: 1,002-1,052) no período pré-vacinação. Cobertura vacinal, longevidade e escolaridade não foram significativas. CONCLUSÕES: Maior IDH e maior riqueza foram fatores de risco para MP, sugerindo necessidade de maior investimento na capacidade diagnóstica de MP nas áreas estudadas, avanços na qualificação da vigilância e notificação da doença / INTRODUCTION: The 10-Valent pneumococcal conjugate vaccine (PCV10) was introduced into the childhood immunization schedule of the Brazilian National Immunization Program in 2010. This study analyzed Pneumococcal Meningitis (PM) incidence rates in Brazil, by age group and federation unit (FU), the spatial distribution of PM incidence rates in under-5 children in Brazil, by FU, in the pre (2005-2009) and post-vaccination (2011-2013) periods, and associations with socioeconomic variables and vaccination coverage. We conducted spatial analysis of PM incidence rates in under-5 children, by municipality in SP, in pre and post-vaccination periods, and evaluated the existence of spatial and spatial-temporal clusters. Spatial statistics was used to test associations of PM incidence rates with socioeconomic variables and vaccine coverage, by state micro regions. METHODS: This is a population-based ecological study using data from the Sistema de Informação de Agravos de Notificação. Vaccine coverage and the Human Development Index (HDI) were used in the Brazilian analysis. In SP analysis, the ecological units were municipalities and micro regions, and the socio-economic variable was the Índice Paulista de Responsabilidade Social (IPRS) of the Fundação Sistema Estadual de Análise de Dados. Thematic maps were built for PM incidence rates in under-5 children, in the pre- and post-vaccination periods, vaccine coverage and HDI, by FU. Thematic maps were also built for PM incidence rates in under-5 children by SP micro regions, in the pre- and post-vaccination periods, vaccination coverage and IPRS using QGis 2.6.1 software. The scanning technique (SatScan 9.2 software) was used to analyze spatial and spatiotemporal clusters in SP. A Bayesian latent Gaussian model with zero-inflated Poisson model through the integrated nested Laplace approximation (INLA) was used in the spatial analysis to evaluate associations of PM incidence rates with vaccine coverage and socioeconomic variables. RESULTS: From 2005 to 2013, 10,769 PM cases were reported. Under-5 children were the most affected in the whole period. In the post-vaccination period (2011-2013), PM incidence rates decreased among under-5 children, especially among infants (from 10.42/100,000, in 2005, to 4.13/100,000, in 2013). Higher PM incidence rates occurred in states with higher HDI. The same occurred in SP, where two municipalities clusters were found in the pre-vaccination period - one of low risk for PM in the northwest of the state (OR, 0.45, p=0.00025), and another of high risk in the southeast, including the state capital (OR, 1.62, p=0.0000051). In the post-vaccination period, only one cluster of higher risk remained in the same area (RR, 1.97, p=0.057). In Bayesian analysis, wealth was identified as a risk factor for PM (RR, 1.026, CI: 1.002-1.052). Vaccination coverage, longevity and education were not important. CONCLUSIONS: A higher HDI as well as greater wealth were risk factors for PM. This result highlights the need to improve the diagnostic capacity of PM in studied areas, advancing in the surveillance quality and disease notification

A meningite bacteriana no período neonatal é uma doença grave, associada à mortalidade elevada e seqüelas em cerca de 12 a 29% dos sobreviventes. Nos recém-nascidos com peso ao nascimento < 2500 g, o risco de adquirir meningite é três vezes superior àqueles com peso >= 2500 g e, entre neonatos de muito baixo peso (< 1500 g), o risco é 17 vezes maior. Objetivo: Geral: descrever o quadro clínico e as complicações da meningite bacteriana em dois grupos de recém-nascidos, considerados de acordo com o peso de nascimento (= 2500 g). Específico: descrever e comparar os agentes etiológicos, a freqüência de sinais e sintomas neurológicos e de complicações, a mortalidade e a duração do tratamento nos dois grupos. Métodos: Estudo observacional de 87 recém-nascidos com meningite bacteriana, admitidos na Unidade de Cuidados Intensivos Neonatais do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, no período de 11 anos (janeiro de 1994 a dezembro de 2004). Os dados foram obtidos através da análise de prontuários. Na análise estatística foram utilizados o teste exato de Fisher e teste não paramétrico de Mann Whitney. Resultados: Foram identificadas bactérias no líquor em 39% dos pacientes, sendo 50% bactérias Gram-positivas e 50% Gram-negativas. A maioria dos neonatos apresentou sinais e sintomas inespecíficos: febre (63,2%), irritabilidade (31%), letargia (26,4%). Os achados neurológicos ocorreram em 35,3% dos casos. As complicações ocorreram em 48,2% dos neonatos, principalmente convulsões (23%), hemorragia intracraniana (14,9%) e hidrocefalia (13,8%) com mortalidade de 11,5 %. Na comparação entre evolução clínica e peso de nascimento observou-se associação entre peso >= 2500 g e convulsão (p=0,047), peso >= 2500 g e fontanela abaulada (p=0,019), bactéria no LCR e complicações (p=0,008) e bactéria no LCR e óbitos (p=0,043). Conclusões: Os agentes etiológicos mais freqüentemente identificados no LCR foram as enterobactérias (41%), seguidas de Streptococcus B (17,5%), Streptococcus não B (17,5%), Staphylococcus aureus (11,7%), Neisseria meningitidis (8,8%) e Enterococcus faecalis (3,0%), não havendo diferença entre tipo de bactérias e peso de nascimento. Os sinais e sintomas predominantes foram inespecíficos, com achados neurológicos em 35% dos casos. A freqüência maior de sintomas neurológicos nos recém-nascidos com peso >= 2500 g, sugere maior grau de maturidade do sistema nervoso central nestas crianças. Embora a mortalidade tenha sido inferior à observada em estudos anteriores no mesmo Serviço, a freqüência de complicações foi alta, independentemente do peso de nascimento. A presença de bactéria no LCR associou-se à maior freqüência de convulsões e mortalidade. A necessidade de manutenção do tratamento por tempo mais prolongado nos recém-nascidos de baixo peso sugere maior gravidade da doença neste grupo de neonatos. / Bacterial meningitis in the neonatal period is a severe disease, associated to elevated mortality and sequelae in around 12 to 29% of the survivors. Newborns whose birth weight is < 2,500g have a 3-fold increase in the risk of acquiring meningitis when compared to those whose weight is >= 2,500; among those with very low birth weight (< 1,500g), the risk increases 17-fold. Objectives: General: to describe the clinical picture and the complications of bacterial meningitis in two groups of newborns, considered according to birth weight (< 2,500g or >= 2,500g). Specific: to describe and compare the etiological agents, the frequency of neurological signs and symptoms and complications, mortality rate and duration of treatment in both groups. Methods: Observational study of 87 newborns with bacterial meningitis, admitted at the Neonatal Intensive Care Unit (NICU) of Instituto da Criança of Hospital das Clínicas of the University of São Paulo School of Medicine, during an 11-year period (January 1994 to December 2004). The data were obtained through the analysis of hospital files. Statistical analysis was carried out with Fisher\'s exact test and the non-parametric Mann Whitney test. Results: Bacteria were identified in the cerebrospinal fluid (CSF) of 39% of the patients, with 50% of them being Gram-positive and 50%, Gram-negative. Most neonates presented unspecific signs and symptoms: fever (63.2%), irritability (31%), and lethargy (26.4%). The neurological findings occurred in 35.3% of the cases. Complications occurred in 48.2% of the neonates, and were mainly seizures (23%), intracranial hemorrhage (14.9%) and hydrocephalus (13.8%) with a mortality rate of 11.5%. At the comparison between clinical evolution and birth weight, associations between weight >= 2,500g and seizures (p=0.047), weight >= 2,500g and concave fontanel (p=0.019), bacteria in the CSF and complications (p=0.008) and bacteria in the CSF and death (p=0.043) were observed. Conclusions: The etiological agents most often identified in the CSF were enterobacteria (41%), followed by B Streptococcus (17.5%), non-B Streptococcus (17.5%), Staphylococcus aureus (11.7%), Neisseria meningitidis (8.8%) and Enterococcus faecalis(3.0%), with no statistical difference between the type of bacteria and birth weight. The predominant signs and symptoms were unspecific, with neurological findings in 35% of the cases. The higher frequency of neurological signs and symptoms in newborns with birth weight >= 2,500g suggest a higher degree of central nervous system maturity in these infants. Although the mortality was lower than that observed in previous studies at the same Service, the frequency of complications was high, regardless of birth weight. The presence of bacteria in the CSF was associated to a higher frequency of seizures and mortality. The need for prolonged treatment in newborns with low birth weight suggests higher disease severity in this group of neonates.

Streptococcus suis de type 2 est un microorganisme pathogène d’importance chez le porc. Il est la cause de différentes pathologies ayant comme caractéristique commune la méningite. C’est également un agent émergeant de zoonose : des cas cliniques humains ont récemment été rapportés en Asie. Cependant, la pathogénèse de S. suis n’est pas encore complètement élucidée. Jusqu’à présent, la réponse pro-inflammatoire initiée par S. suis n’a été étudiée qu’in vitro. L’étude du choc septique et de la méningite requiert toujours des modèles expérimentaux appropriés. Au cours de cette étude, nous avons développé un modèle in vivo d’infection chez la souris qui utilise la voie d’inoculation intra-péritonéale. Ce modèle a servi à l’étude de la réponse pro-inflammatoire associée à ce pathogène, tant au niveau systémique qu’au niveau du système nerveux central (SNC). Il nous a également permis de déterminer si la sensibilité aux infections à S. suis pouvait être influencée par des prédispositions génétiques de l’hôte. Le modèle d’infection par S. suis a été mis au point sur des souris de lignée CD1. Les résultats ont démontré une bactériémie élevée pendant les trois jours suivant l’infection. Celle-ci était accompagnée d’une libération rapide et importante de différentes cytokines pro-inflammatoires (TNF-α, IL-6, IL-12p40/p70, IFN-ɣ) et de chémokines (KC, MCP-1 and RANTES), qui ont entraîné un choc septique et la mort de 20 % des animaux. Ensuite, pour confirmer le rôle de l’inflammation sur la mortalité et pour déterminer si les caractéristiques génétiques de l’hôte pouvaient influencer la réponse inflammatoire et l’issue de la maladie, le modèle d’infection a été étendu à deux lignées murines consanguines différentes considérées comme résistante : la lignée C57BL/6 (B6), et sensible : la lignée A/J. Les résultats ont démontré une importante différence de sensibilité entre les souris A/J et les souris B6, avec un taux de mortalité atteignant 100 % à 20 h post-infection (p.i.) pour la première lignée et de seulement 16 % à 36 h p.i. pour la seconde. La quantité de bactéries dans le sang et dans les organes internes était similaire pour les deux lignées. Donc, tout comme dans la lignée CD1, la bactériémie ne semblait pas être liée à la mort des souris. La différence entre les taux de mortalité a été attribuée à un choc septique non contrôlé chez les souris A/J infectées par S. suis. Les souris A/J présentaient des taux exceptionnellement élevés de TNF-α, IL-12p40/p70, IL-1β and IFN- γ, significativement supérieurs à ceux retrouvés dans la lignée B6. Par contre, les niveaux de chémokines étaient similaires entre les lignées, ce qui suggère que leur influence est limitée dans le développement du choc septique dû à S. suis. Les souris B6 avaient une production plus élevée d’IL-10, une cytokine anti-inflammatoire, ce qui suppose que la cascade cytokinaire pro-inflammatoire était mieux contrôlée, entraînant un meilleur taux de survie. Le rôle bénéfique potentiel de l’IL-10 chez les souris infectées par S. suis a été confirmé par deux approches : d’une part en bloquant chez les souris B6 le récepteur cellulaire à l’IL-10 (IL-10R) par un anticorps monoclonal anti-IL-10R de souris et d’autre part en complémentant les souris A/J avec de l’IL-10 de souris recombinante. Les souris B6 ayant reçu le anticorps monoclonal anti-IL-10R avant d’être infectées par S. suis ont développé des signes cliniques aigus similaires à ceux observés chez les souris A/J, avec une mortalité rapide et élevée et des taux de TNF-α plus élevés que les souris infectées non traitées. Chez les souris A/J infectées par S. suis, le traitement avec l’IL-10 de souris recombinante a significativement retardé l’apparition du choc septique. Ces résultats montrent que la survie au choc septique dû à S. suis implique un contrôle très précis des mécanismes pro- et anti-inflammatoires et que la réponse anti-inflammatoire doit être activée simultanément ou très rapidement après le début de la réponse pro-inflammatoire. Grâce à ces expériences, nous avons donc fait un premier pas dans l’identification de gènes associés à la résistance envers S. suis chez l’hôte. Une des réussites les plus importantes du modèle d’infection de la souris décrit dans ce projet est le fait que les souris CD1 ayant survécu à la septicémie présentaient dès 4 jours p.i. des signes cliniques neurologiques clairs et un syndrome vestibulaire relativement similaires à ceux observés lors de méningite à S. suis chez le porc et chez l’homme. L’analyse par hybridation in situ combinée à de l’immunohistochimie des cerveaux des souris CD1 infectées a montré que la réponse inflammatoire du SNC débutait avec une augmentation significative de la transcription du Toll-like receptor (TLR)2 et du CD14 dans les microvaisseaux cérébraux et dans les plexus choroïdes, ce qui suggère que S. suis pourrait se servir de ces structures comme portes d’entrée vers le cerveau. Aussi, le NF-κB (suivi par le système rapporteur de l’activation transcriptionnelle de IκBα), le TNF-α, l’IL-1β et le MCP-1 ont été activés, principalement dans des cellules identifiées comme de la microglie et dans une moindre mesure comme des astrocytes. Cette activation a également été observée dans différentes structures du cerveau, principalement le cortex cérébral, le corps calleux, l’hippocampe, les plexus choroïdes, le thalamus, l’hypothalamus et les méninges. Partout, cette réaction pro-inflammatoire était accompagnée de zones extensives d’inflammation et de nécrose, de démyélinisation sévère et de la présence d’antigènes de S. suis dans la microglie. Nous avons mené ensuite des études in vitro pour mieux comprendre l’interaction entre S. suis et la microglie. Pour cela, nous avons infecté des cellules microgliales de souris avec la souche sauvage virulente (WT) de S. suis, ainsi qu’avec deux mutants isogéniques, un pour la capsule (CPS) et un autre pour la production d’hémolysine (suilysine). Nos résultats ont montré que la capsule était un important mécanisme de résistance à la phagocytose pour S. suis et qu’elle modulait la réponse inflammatoire, en dissimulant les composants pro-inflammatoires de la paroi bactérienne. Par contre, l’absence d’hémolysine, qui est un facteur cytotoxique potentiel, n’a pas eu d’impact majeur sur l’interaction de S. suis avec la microglie. Ces études sur les cellules microgliales ont permis de confirmer les résultats obtenus précédemment in vivo. La souche WT a induit une régulation à la hausse du TLR2 ainsi que la production de plusieurs médiateurs pro-inflammatoires, dont le TNF-α et le MCP-1. S. suis a induit la translocation du NF-kB. Cet effet était plus rapide dans les cellules stimulées par le mutant déficient en CPS, ce qui suggère que les composants de la paroi cellulaire représentent de puissants inducteurs du NF-kB. De plus, la souche S. suis WT a stimulé l’expression de la phosphotyrosine, de la PKC et de différentes cascades liées à l’enzyme mitogen-activated protein kinase (MAPK). Cependant, les cellules microgliales infectées par le mutant déficient en CPS ont montré des profils de phosphorylation plus forts et plus soutenus que celles infectées par le WT. Finalement, la capsule a aussi modulé l’expression de l’oxyde nitrique synthétase inductible (iNOS) induite par S. suis et par la production subséquente d’oxyde nitrique par la microglie. Ceci pourrait être lié in vivo à la neurotoxicité et à la vasodilatation. Nous pensons que ces résultats contribueront à une meilleure compréhension des mécanismes sous-tendant l’induction de l’inflammation par S. suis, ce qui devrait permettre, d’établir éventuellement des stratégies plus efficaces de lutte contre la septicémie et la méningite. Enfin, nous pensons que ce modèle expérimental d’infection chez la souris pourra être utilisé dans l’étude de la pathogénèse d’autres bactéries ayant le SNC pour cible. / Streptococcus suis serotype 2 is an important swine pathogen responsible for diverse infections, meningitis being its most striking feature. In addition, it is an emerging agent of zoonosis, which has gained worldwide attention due to important outbreaks in Asia. Understanding the pathogenesis of S. suis infections still represents a challenge. Up to present, the pro-inflammatory response due to S. suis has only been studied in vitro, and there is still a great need of appropriate experimental models for both septic shock and meningitis. In the present study, we successfully developed an in vivo model of S. suis infection in adult mice infected by the intraperitoneal route. This model served to investigate the pro-inflammatory events that take place at both the systemic and Central Nervous System (CNS) levels associated with this important pathogen. In addition, this model was useful to determine if susceptibility to S. suis infection may be influenced by the genetic background of the host. The mouse model of S. suis infection was standardized in CD1 mice. Results showed sustained bacteremia during the 3 days post-infection (p.i.), accompanied by a quick and substantial release of different pro-inflammatory cytokines (TNF-α, IL-6, IL-12p40/p70, IFN-ɣ) and chemokines (KC, MCP-1 and RANTES) that lead to septic shock and 20% mortality in mice. Once the hallmark of the septic phase of S. suis infection was established in CD1 mice, research continued with the objective to confirm the role of inflammation in mortality and to determine if the genetic background of the host may influence the inflammatory response toward this pathogen and the further outcome of the disease. For this, the mouse model of S. suis infection was used with two genetically different inbred mouse strains, this is, C57BL/6 (B6) and A/J mice, which are considered as the prototype of Th1-type and Th2-type mice, respectively. Results demonstrated a striking susceptibility to S. suis infection in A/J mice in comparison to B6 mice, with 100% mortality in the former mice strain at 20 h p.i., and 16 % mortality at 36 h p.i. for the latter. Very interestingly, and similarly to CD1 mice, bacteremia did not seem to be responsible for the death of mice, as both mice strains presented similar amounts of bacteria in blood and organs. Thus, it was postulated that the higher mortality in S. suis-infected A/J mice was due to uncontrolled septic shock. In fact, A/J mice presented very high levels of TNF-α, IL-12p40/p70, IL-1β and IFN-ɣ, that significantly exceeded those found in B6 mice. Remarkably, chemokine levels were similar between strains, suggesting their limited participation in the development of septic shock by S. suis. A greater survival of B6 mice was partially related to a better regulation of the pro-inflammatory cytokine cascade, as they showed a higher production of the anti-inflammatory cytokine IL-10 than A/J mice. The potential beneficial role of the IL-10 in mice infected with S. suis was confirmed using two approaches: the first, by blockage of the cell receptor of IL-10 (IL-10R) with an anti-mouse IL-10R monoclonal antibody (Mab) in B6 mice and the second by administrating recombinant mouse (rm)IL-10 (rmIL-10) to A/J mice. B6 mice that received the IL-10R MAb treatment before challenge with S. suis developed a clinical acute disease similar to that observed with A/J mice, with a striking and rapid increase in mortality and higher levels of TNF-α in comparison to those of infected mice that did not receive the treatment. Controversially, treatment with rmIL-10 significantly delayed the onset of septic shock in A/J mice infected with S. suis. These results show that survival from S. suis septic shock requires a tight regulation of pro- and anti-inflammatory mechanisms, and that the latter should be activated at the same time or soon after the onset of the pro-inflammatory response. This part of the study may represent a first step in the identification of host genes associated with resistance against S. suis. One of the most important achievements of the mouse model of infection described in this project is the development of distinct clinical signs of neurological disease in CD1 mice from 4 days p.i. Indeed, in CD1 mice that survived sepsis due to S. suis infection, clinical signs of neurological disease and vestibular syndrome, which are quite similar to those observed in clinical cases of S. suis meningitis in both pigs and humans, were observed. Studies of the brains of infected CD1 mice using in situ hybridization combined with immunocytochemistry, demonstrated that the CNS inflammatory response began with a significant increase in the transcription of Toll-like receptor (TLR)2 and CD14 initially in the brain microvasculature and choroid plexuses, suggesting that S. suis may use these structures as portals of entry to the brain. There also was activation of NF-κB (as indicated by transcriptional activation of IκBα as a reporter system) and TNF-α, IL-1β and MCP-1, mainly in cells identified as microglia and to a lesser extent in astrocytes. These signals reached different brain structures, mainly the brain cortex, corpus callosum, hippocampus, choroid plexuses, thalamus, hypothalamus and meninges. All of these pro-inflammatory events were associated with extensive areas of inflammation and necrosis, severe demyelination and presence of antigens of S. suis inside microglia. In vitro studies were conducted in order to better understand the interactions of S. suis and microglia. For this, mouse microglia were infected with a virulent wild type (WT) strain of S. suis. Two isogenic mutants deficient in capsule (CPS) or hemolysin production (suilysin, SLY) respectively, were also included for comparative purposes. The CPS was important for S. suis resistance to phagocytosis, and it also modulated the inflammatory response by hiding pro-inflammatory components from the bacterial cell wall. On the other hand, the absence of SLY, a potential cytotoxic factor, did not have a major impact on S. suis interactions with microglia. Studies with microglia helped to confirm previous findings in vivo in mice, as the WT S. suis strain induced the up-regulation of TLR2 and the production of several pro-inflammatory mediators, including TNF-α and MCP-1. As observed in mice, S. suis induced NF-kB translocation, which was more rapid for cells stimulated with the CPS-deficient mutant, suggesting that bacterial cell wall components are potent inducers of NF-kB. Moreover, WT S. suis promoted phosphotyrosine, PKC and different mitogen-activated protein kinase (MAPK) events. However, microglia infected with the CPS-deficient mutant showed overall stronger and more sustained phosphorylation profiles. Finally, the CPS also modulated S. suis-induced inducible nitrogen oxide synthase (iNOS) expression and further nitric oxide production in microglia, which could be related to neurotoxicity and vasodilatation in vivo. We are confident that our results may help to more fully understand the mechanisms underlying S. suis induction of inflammation, leading to the design of more efficient anti-inflammatory strategies for sepsis and meningitis. Finally, we believe this experimental model of infection in mice could also be useful for studying the pathogenesis of infections of the CNS, due to other bacteria.

This thesis is composed of two economic evaluations: one trial-based study and one model-based study. In a recent study published in Clinical Infectious Diseases in 2011, a team of OUCRU investigators found that immediate antiretroviral therapy (ART) was not associated with improved 9-month survival in HIV-associated TBM patients (HR, 1.12; 95&percnt; CI, .81 to–1.55; P = .50). An economic evaluation of this clinical trial was conducted to examine the cost-effectiveness of immediate ART (initiate ART within 1 week of study entry) versus deferred ART (initiate ART after 2 months of TB treatment) in HIV-associated TBM patients. Over 9 months, immediate ART was not different from deferred ART in terms of costs and QALYs gained. Late initiation of ART during TB and HIV treatment for HIV-positive TBM patients proved to be the most cost-effective strategy. Increasing resistance of Plasmodium falciparum malaria to artemisinin is posing a major threat to the global effort to eliminate malaria. Artesmisinin combination therapies (ACT) are currently known as the most efficacious first-line therapies to treat uncomplicated malaria. However, resistance to both artemisinin and partner drugs is developing and this could result in increasing morbidity, mortality, and economic costs. One strategy advocated for delaying the development of resistance to the ACTs is the wide-scale deployment of multiple first-line therapies. A previous modeling study examined that the use of multiple first-line therapies (MFT) reduced the long-term treatment failures compared with strategies in which a single first-line ACT was recommended. Motivated by observed results of the published modelling study in the Lancet, the cost-effectiveness of the MFT versus the single first-line therapies was assessed in settings of different transmission intensities, treatment coverages and fitness cost of resistance using a previously developed model of the dynamics of malaria and a literature –based cost estimate of changing antimalarial drug policy at national level. This study demonstrates that the MFT strategies outperform the single first-line strategies in terms of costs and benefits across the wide range of epidemiological and economic scenarios considered. The second analysis of the thesis is not only internationally relevant but also with a focus towards healthcare practice in Vietnam. These two studies add significant new cost-effectiveness evidence in Vietnam. This thesis presents the first trial-based economic evaluation in Vietnam considers patient-health outcome measures as the participants have cognitive limitations (tuberculous meningitis), dealing with missing data along with the potential ways to handle this common problem by the use of multiple imputation, and the issues of censored costs data. Having identified these issues would support the decision makers or stakeholders including the pharmaceutical industry to devise a new guideline on how to implement a well-design trial-based economic evaluation in Vietnam in the future. Another novelty of this thesis is the introduction of the detailed of costing of drug regimens change in which the economic evaluations considering the drug policy change often do not include. This cost could be substantial to the healthcare system for retraining the staff and publishing the new guidelines. This thesis will document the costs incurred by the Vietnamese government by changing the first-line treatment of malaria, from single first-line therapy (ACT) to multiple first-line therapies.

Eine der häufigsten viralen Infektionskrankheiten im Kindesalter ist gegenwärtig die Parotitis epidemica. Mit dem Auftreten einer abakteriellen Meningitis bei Kindern als Folge einer Mumpsvirusinfektion ist in über 80% der Fälle zu rechnen. 1. In serologisch bestätigten Mumpsfällen wurden Liquorproben von Kindern mit einer Meningitis immunfluoreszenzoptisch untersucht. In den lympho-monozytären Liquorzellen konnte das Mumpsantigen in 64% der Fälle nachgewiesen werden. 2. Der immunfluoreszenzoptisch Nachweis des Mumpsantigens in Liquorzellen stellt eine Erweiterung der diagnostischen Möglichkeiten bei serösen Meningitiden des Kindes unklarer Äthiologie dar. 3. Während der Prüfung von Mumpsviren reagieren intracerebral infizierte Affen mit einer statistisch gesicherten Erhöhung der Liquorzellzahl. Bei Affen, die mit einer neuropathogenen Variante infiziert waren, sind die Liquorzellzahlen auch 28 Tage p.i. signifikant höher im Vergleich zu mit Impfstoff infizierten Tieren. Der Nachweis des Mumpsantigens in den Liquorzellen beweist die Spezifität der experimentellen Mumpsmeningitis bei Affen. Das virale Antigen wird nur innerhalb der ersten Versuchswoche in den Liquorzellen detektiert, nach 3 – 4wöchiger Versuchsdauer ist das Mumpsvirus im Liquor der Affen nicht mehr nachweisbar. Diese Befunde sind mit den Befunden bei natürlichen Mumpsmeningitiden der Kinder vergleichbar. 4. Minischweine und Katzen reagieren auf intracerebral appliziertes Mumpsvirus mit charakteristischen liquorzytologischen Veränderungen, die mit den Befunden beim Affen korrelieren. Sie reagieren auf intracerebral inokuliertes Mumpsvirus bereits in der ersten Woche mit einer deutlichen Liquorpleozytose. Die Höhe der Zellzahl im Liquor ist bei Mumpswildviren (α = 0,05) bedeutend größer als bei den Impfviren. Die Zellzahlerhöhung ist nach 8 Wochen nicht auf die Normalwerte zurückgegangen. 5. Der immunfluoreszenzoptische Nachweis des Mumpsantigens in den Liquorzellen der Minischweine und Katzen ist zeitlich begrenzt. Es ergaben sich Unterschiede zwischen Mumpsviren vom Wild- und Impftyp. Der Nachweis des viralen Antigens in den Liquorzellen war 4 Wochen p.i. nicht mehr möglich. 6. Das Differentialzellbild des Liquors ist bei allen Tiermodellen durch lympho-monozytäre Zellen gekennzeichnet, wobei monozytäre Zellformen zu jedem Zeitpunkt der Infektion überwiegen. 7. Vor der Anwendung von Lebendimpfstoffen beim Menschen ist eine tierexperimentelle Sicherheitsprüfung notwendig. Die Einbeziehung der Liquordiagnostik (Verlauf der Pleozytose und der fluoreszenzoptische Antigennachweis in den Liquorzellen) ist eine wesentliche Ergänzung zur Charakterisierung der neurotropen Eigenschaften des viralen Mumpsantigens. / One of the most common viral infectious diseases in childhood is currently parotitis epidemica. The occurrence of abacterial meningitis in children as a result of mumps virus infection can be expected in more than 80% of cases. 1. In serologically confirmed mumps cases, cerebrospinal fluid samples from children with meningitis were examined by immunofluorescence. Mumps antigen was detected in the lympho-monocytic cerebrospinal fluid (CSF) cells in 64% of cases. 2. Immunofluorescence detection of mumps antigen in CSF cells represents an extension of diagnostic possibilities in serous meningitis of the child of unclear etiology. 3. During mumps virus testing, intracerebrally infected monkeys respond with a statistically confirmed increase in CSF cell count. In monkeys infected with a neuropathogenic variant, CSF cell counts are significantly higher even 28 days p.i. compared with vaccine-infected animals. Detection of mumps antigen in CSF cells demonstrates the specificity of experimental mumps meningitis in monkeys. The viral antigen is detected in the CSF cells only within the first week of the experiment; after 3 - 4 weeks of the experiment, the mumps virus is no longer detectable in the CSF of the monkeys. These findings are comparable to the findings in natural mumps meningitis of children. 4. Minipigs and cats respond to intracerebrally applied mumps virus with characteristic liquor cytologic changes that correlate with the findings in monkeys. They respond to intracerebrally inoculated mumps virus with marked CSF pleocytosis as early as the first week. The level of cell number in CSF is significantly greater in wild mumps virus (α = 0.05) than in vaccine virus. The cell count increase did not return to normal values after 8 weeks. 5. Immunofluorescence detection of mumps antigen in CSF cells of minipigs and cats is temporal. Differences were found between wild-type and vaccine-type mumps viruses. Detection of viral antigen in CSF cells was no longer possible 4 weeks p.i.. 6. The differential cell pattern of CSF is characterized by lympho-monocytic cells in all animal models, with monocytic cell forms predominating at each time point of infection. 7. Animal safety testing is required prior the use of live vaccines in humans. The inclusion of CSF diagnostics (course of pleocytosis and fluorescence antigen detection in CSF cells) is an essential addition to characterize the neurotropic properties of the viral mumps antigen.

No description available.

Serious illness in childhood is a rare occurrence, but accounts for 20% of childhood deaths. Early recognition and treatment of serious illness is vital if the child is to recover without long-term disability. It is known that vital signs such as heart rate, respiratory rate, temperature, and oxygen saturation can be used to identify children who are at high risk of serious illness. This thesis presents research into the development of a vital signs monitor, designed for use in the initial assessment of unwell children at their first point of contact with a medical practitioner. Child-friendly monitoring techniques are used to obtain vital signs, which can then be combined using data fusion techniques to assist clinicians in identifying children with serious illness. Existing normal ranges for heart rate and respiratory rate in childhood vary considerably, and do not appear to be based on clinical evidence. This thesis presents a systematic meta-analysis of heart rate and respiratory rate from birth to 18 years of age, providing evidence-based curves which can be used to assess the degree of abnormality in these important vital signs. Respiratory rate is particularly difficult to measure in children, but is known to be predictive of serious illness. Current methods of automated measurement can be distressing, or are time-consuming to apply. This thesis therefore presents a novel method for estimating the respiratory rate from an optical finger sensor, the pulse oximeter, which is routinely used in clinical practice. Information from multiple vital signs can be used to identify children at risk of serious illness. A number of data fusion techniques were tested on data collected from children attending primary and emergency care, and shown to outperform equivalent existing scoring systems when used to identify those with more serious illness.