O vírus de influenza aviária H5N1 tem se disseminado rapidamente por diversos países e continentes nos últimos anos, gerando grandes perdas econômicas e de vidas humanas. Existe a possibilidade de a doença chegar ao Brasil, o que provocaria elevado impacto sobre a economia, especialmente sobre o setor avícola. A ausência e a necessidade de estimativas de impacto econômico no país, derivadas de surtos de gripe aviária em território brasileiro, motivaram a presente pesquisa. Visando gerar tais estimativas e analisá-las, foram simulados três cenários utilizando-se de um modelo aplicado de equilíbrio geral inter-regional, denominado TERM-BR. O primeiro cenário (Cenário I) contempla um foco da doença no Rio Grande do Norte, região Nordeste do país. O segundo (Cenário II) simula a presença de diversos focos da doença no estado de São Paulo. O terceiro (Cenário III) considera o surgimento de diversos focos presentes nos estados Rio Grande do Norte, Rondônia, São Paulo e Rio Grande do Sul. Os resultados sinalizam impactos de maior dimensão na medida em que os focos da doença surgem próximos aos mercados produtores, exportadores e consumidores, como é o caso da região Sul e Sudeste. Na região Sul, em função da dimensão da avicultura na economia local, a crise do setor avícola acaba refletindo negativamente e acentuadamente sobre o conjunto da economia local. Nas regiões Norte e Nordeste, as restrições sobre a aquisição de aves vivas pelas famílias têm grande peso na retração da atividade econômica do setor avícola, já que a atividade de abate é pouco representativa e parcela importante das aves é adquirida diretamente pelas famílias, o que não acontece na mesma dimensão nas demais regiões do país. Observa-se também que o aumento do consumo de carne bovina e suína contribui para reduzir a crise na economia estadual nos estados produtores, e é também a fonte de crescimento para os estados em que a bovinocultura se destaca. O choque de demanda doméstica de produtos avícolas, comparado com os demais choques, revela-se como o principal responsável pelo comportamento na produção em quase todos os estados. Já a redução das exportações tem grande peso sobre o comportamento da produção avícola quando o foco da doença é na região exportadora ou próxima a ela. No estado de Santa Catarina, o choque de exportações prepondera sobre a queda do consumo doméstico quando do fechamento quase total dos mercados externos para carne de aves. Por último, o choque de oferta, via mortalidade das aves e destruição de ovos, pouco influencia a magnitude da queda na produção dos produtos da avicultura. / In the past few years, the bird flue virus H5N1 spread rapidly through various countries and continents, causing great economic and human losses. There is also the possibility of the disease arriving in Brazil, which would have a substantial impact on the country\'s economy, particularly on its poultry sector. The present study addresses the lack of estimates of the potential economic consequences of a bird flu outbreak on commercial poultry production in Brazil. The analysis consists of three simulations using a interregional general equilibrium model called TERM-BR. The first scenario focuses on an outbreak in the state of Rio Grande do Norte in the Northeastern part of the country. The second scenario simulates an outbreak at various places in the State of Sao Paulo, and the third scenario assesses the consequences of a bird flue outbreak in various states simultaneously, Rio Grande do Norte, Rondônia, São Paulo and Rio Grande do Sul. The results indicate greater economic impact when the outbreak occurs close to points of production and consumption, which is the case in the Southern and Southeastern regions of Brazil. In the South, where the poultry sector constitutes a larger share of the local economy, a potential avian flu outbreak will also have a greater negative economic impact. In the Northern and Northeastern region, live birds are generally purchased and slaughtered directly by individual families living in suburban and small town settings rather then by large scale processors and packinghouses. This characteristic explains why potential restrictions on these small purchases of live birds will have a very large negative economic impact on the poultry sector in the affected states. A possible reduction in poultry supply could however be offset by an increase in beef and pork consumption, thereby softening the economic affect of a bird flue outbreak by promoting growth of the beef and pork industry. In most states, this fall of domestic poultry demand is the primary cause for a shift in production. In contrast, the fall in export demand only weighs heavily on the local economy when the outbreak occurs close to exporting regions. In the state of Santa Catarina, for example, the effect of a fall in export demand dominates the effect of a fall in domestic demand, as export markets are almost completely shutdown. Finally, the reduction in poultry supply through death of infected birds and destruction of eggs, has little affect on the decrease of poultry production.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-03-03T18:20:34Z No. of bitstreams: 1 josyannedarochaferreira.pdf: 3993746 bytes, checksum: 5b88976087115752d440dac956977da3 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T01:48:23Z (GMT) No. of bitstreams: 1 josyannedarochaferreira.pdf: 3993746 bytes, checksum: 5b88976087115752d440dac956977da3 (MD5) / Made available in DSpace on 2016-04-24T01:48:23Z (GMT). No. of bitstreams: 1 josyannedarochaferreira.pdf: 3993746 bytes, checksum: 5b88976087115752d440dac956977da3 (MD5) Previous issue date: 2013-07-05 / O envelhecimento produz mudanças fisiológicas e funcionais que podem reduzir a capacidade funcional e aumentar a vulnerabilidade do idoso em relação às doenças respiratórias. Em Minas Gerais, estas se configuram como a segunda causa de internação e a terceira de morte entre os idosos. Dentre essas afecções, destacam-se as relacionadas à influenza, cuja principal estratégia para redução do seu impacto é a vacinação anual, inserida no calendário vacinal brasileiro em 1999. O objetivo do estudo foi analisar a tendência da mortalidade por doenças respiratórias relacionadas à influenza nos idosos do Estado de Minas Gerais, 1980 a 2010 e comparar o comportamento dessas séries temporais no período anterior e posterior à inserção da vacina contra influenza no calendário vacinal. Trata-se de estudo ecológico de séries temporais, com utilização de dados sobre mortalidade por doenças respiratórias relacionadas à influenza de indivíduos com mais de 60 anos, residentes no Estado de Minas Gerais. O indicador utilizado foi taxa de mortalidade por causas específicas, por faixa etária (60 a 69 anos, 70 a 79 anos e 80 anos ou mais), sexo e macrorregião de residência. Para as comparações entre as macrorregiões de saúde, sexo e períodos estudados, as taxas de mortalidade pelas causas selecionadas foram ajustadas pela faixa etária, conforme a técnica de padronização pelo método direto (população padrão: Minas Gerais, 2010). A análise da mortalidade foi realizada por meio da descrição das taxas ao longo do tempo e também por meio da comparação da tendência através de modelos de regressão linear. Os modelos foram ajustados pelo percentual de óbitos por causa mal definida e, para o período posterior a inserção da campanha, também pela cobertura vacinal. O nível de significância adotado foi de 5%. Foram utilizados dados do Sistema de Informação sobre Mortalidade, Sistema de Informação do Programa Nacional de Imunização e do Instituto Brasileiro de Geografia e Estatística. As análises das tendências da mortalidade por doenças respiratórias relacionadas à influenza nos idosos de Minas Gerais realizadas sugerem um impacto positivo da intervenção vacinal contra a influenza na redução da mortalidade. Taxas mais elevadas foram observadas entre os homens e nos idosos com idade mais avançada, independentemente do sexo, para Minas Gerais e suas macrorregiões e analisando todo o período, as tendências das taxas de mortalidade apresentaram-se crescentes. Ao comparar o período anterior e posterior à inserção da vacina, para Minas Gerais e suas macrorregiões, evidenciou-se no período anterior uma tendência significativa crescente das taxas e inversão ou estabilização da tendência no período posterior, com exceção da macrorregião norte, em que a tendência permaneceu crescente. Observaram-se variações regionais em relação às taxas de mortalidade, qualidade dos dados do SIM e cobertura vacinal entre as macrorregiões estudadas. A mudança na tendência da mortalidade por doença respiratória relacionada à influenza após as campanhas vacinais sugere um efeito protetor na mortalidade dos idosos de Minas Gerais e fomenta o debate sobre a imunização desse grupo populacional e o aprimoramento das políticas considerando as diversidades regionais. / Aging produces physiological and functional changes which may decrease functional capacity and increase vulnerability of the elderly regarding respiratory disease. In Minas Gerais, these are the second cause of hospitalization and the third cause of death among the elderly. Among these illnesses are those related to influenza, for which the main strategy to reduce its impact is annual vaccination, as provided in the 1999 Brazilian Vaccination Schedule. The aim of this study is to analyse the mortality trends due to influenza-related respiratory diseases in the elderly in the state of Minas Gerais, from 1980 to 2010, and compare the behavior of these time series before and after the inclusion of the influenza vaccine in the vaccination schedule. This is an ecological time series study based on data for mortality due to influenza-related respiratory diseases for subjects over 60 years old living in the state of Minas Gerais. The indicators we used are cause-specific mortality rate, age group (60-69, 70-79, and ≥ 80 years old), sex, and residential macro-region. In order to compare health, sex, and study period macro-regions, mortality rates due to the selected causes were adjusted by age group according to the direct method standardization technique (standard population: Minas Gerais, 2010). Mortality analysis was done by describing rates along time and also by comparing trends through linear regression models. Models were adjusted by percent deaths due to poorly defined cause and also by vaccination coverage after introduction of the campaign. The significance level we used was of 5%. We used data from the Mortality Information System, the National Immunization Program Information System, and the Brazilian Institute of Geography and Statistics. The mortality trends due to influenza-related diseases in the elderly in the state of Minas Gerais suggest a positive impact of the vaccination intervention against influenza in decreasing mortality. Higher rates were seen among men and the elderly at a more advanced age, regardless of sex, for Minas Gerais and its macro-regions. According to the analysis, mortality rate trends increased throughout the period. By comparing the periods before and after the inclusion of vaccination in Minas Gerais and its macro-regions, a significantly increasing trend was seen in the rates before the implementation of the program, and an inversion and stabilization of the trends after implementation, except the Northern macro-region where trends remained constant. Regional variations were seen for mortality rates, SIM data quality and vaccination coverage among the macro-regions included in the study. Changes in mortality rate due to influenza-related respiratory diseases after vaccination campaigns suggest a protective effect for mortality in the elderly in the state of Minas Gerais and raise a debate about the immunization of this population and policy enhancement by considering regional differences.

M.Tech. (Homoeopathy) / Upper Respiratory tract viral infections (URTIs), such as influenza and the common cold, are a group of common infections in the human population. They have a seemingly mild nature, but studies have found them to be a major cause of morbidity and mortality worldwide (Wat, 2004). In the western world, the majority of pre-school childrenconsult a doctor for a respiratory infection at least once a year. Conventional medical treatment options are said to be limited, and antibiotics are often unnecessarily prescribed.The frequency of antibiotic prescriptions has caused a resistance of pathogenic bacteria against these antibiotics, and this in turn, has become a major threat to treatment (Schönbeck et al., 2005). A traditional South African herb, Pelargonium sidoides (P. sidoides), has been shown to have antibacterial, antiviral, and immunomodulatory properties in many investigations (Brendler, 2009). No studies have been done to date assessing the efficacy of P. sidoides as a prophylactic for influenza and the common cold in children. This study aimed at establishing the efficacy of Linctagon® Syrup in the prevention of colds and influenza in pre-school children. The study was a double- blind, placebo–controlled study whereby thirty healthy children aged four to six years old were placed into two groups using matched pairs according to gender. Fifteen participants were allocated to the experimental group whereby the Linctagon® Syrup was taken for the duration of the study. The other fifteen participants were allocated in the placebo group for the duration of the study and given a placebo syrup. Parents / guardians were requested to read the Participant Information Leaflet (Appendix B), and sign the Participant Details and Consent Form (Appendix C,) and the participants were requested to sign the Participation of Minor Assent Form (Appendix D). On day 0, the parents / guardians signed the forms and the initial visit took place. The researcher conducted an ear, nose, throat and respiratory examination on each participant and vital signs were measured. The medication was randomised by an independent person at Nativa Laboratories. Each participant received two 150ml bottles of either the Linctagon® syrup or placebo syrup, and parents / guardians were advised on how to administer the medication (Appendix E), by the researcher. The participants were required to take 2.5ml twice daily for a period of sixty days. A Weekly Progress Questionnaire (Appendix F) was handed to the parents / guardians of each child, and they were requested to fill them in over an eight week period. This questionnaire assessed the wellness of the child for the duration of the study and involved a 4-point rating system to assess the severity of symptoms for both influenza and the common cold. Weekly telephone calls were made to the participants’ parents / guardians to follow up on progress. A final visitation occurred on day 60, and included the collection of the questionnaires. The parents / guardians were requested to fill in a score card at the end of the study, rating the effectiveness of Linctagon® Syrup in the prevention of colds and influenza in their child (Appendix G). The data was statistically analysed by Statkon at the University of Johannesburg by means of non-parametric tests, namely: descriptive data, Cochran’s test, Chi-square test, cross tabulation, Mann-Whitney U test and the Friedman test. The research study determined that Linctagon® Syrup did not have a statistically significant effect in the prevention of influenza and the common cold in children, in support of the null hypothesis. Linctagon® Syrup also had no effect on reducing the incidence, frequency or duration of symptoms in those children who became ill, however this may be due to the relativity low dosage prescribed. Further large scale studies are recommended to validate these results.The score card (subjective rating on the efficacy of the syrup) showed a statistically significant result between the two groups, in favour of the treatment group.

Le traitement actuel de la grippe repose sur des antiviraux ciblant des protéines virales qui peuvent induire l'apparition de virus résistants. Pour limiter ce risque, des thérapeutiques alternatives sont développées qui ciblent des partenaires cellulaires indispensables au virus. Cette thèse s'inscrit dans cette recherche de nouveaux antiviraux ciblant des protéines cellulaires et dans l'étude des relations hôte-pathogène indispensable à leur mise au point. Nous proposons une méthode innovante pour l'identification d'antiviraux basée sur la signature transcriptionnelle cellulaire d'infection commune à 5 virus influenza de type A appartenant à des sous types différents (H1N1, H3N2, H5N1, H5N2 et H7N1). Huit molécules induisant un profil transcriptionnel inverse à celui de l'infection ont été sélectionnées dans la base de donnée Connectivity map et 7 molécules se sont révélées antivirales sur au moins un des virus testés in vitro. Cette étude est la première à montrer qu'une sélection basée sur le profil d'expression génique peut être utilisée pour identifier des antiviraux. Cette étude transcriptomique permet en outre de caractériser les réponses cellulaires spécifiques à différents sous-types viraux. Alors que le virus H1N1 modifie peu la transcription cellulaire, les virus H3N2, H5N1, H5N2 et H7N1 modulent l'expression de gènes impliqués dans les voies MAPK, NF-KB, IRF3 et p53. L'analyse de l'implication fonctionnelle des modifications spécifiques des voies de transduction cellulaire pourrait permettre de mieux comprendre la pathogenèse particulière de certaines souches virales / The current treatment of flu relies on antiviral drug targeting viral proteins that can induce the appearance of resistant virus. To limit this risk, alternative therapies are developed that target essential cellular partners of the virus. This thesis is part of this search for new therapeutic and of the study of host-pathogen interactions essential to their development. We proposed an innovative method for the identification of antiviral drugs based on the cell gene- expression profile associated with infection with five different influenza A virus strains belonging to different subtypes (H1N1, H3N2, H5N1, H5N2 and H7N1). Eight molecules inversing the infection signature were selected from the Connectivity Map database and 7 molecules inhibited viral growth on at least one of the viruses tested in vitro. This is the first study showing that gene expression- based screening can be used to identify antivirals. This transcriptomic study provides further characterization of strain specific cellular responses. While HlN1 virus changes slightly cellular transcription, H3N2, H5N1, H5N2 and H7N1 viruses modulate the expression of genes involved in MAPK, NF-kB, IRF3 and p53 pathways. Analysis of the functional involvement of specific modifications of cellular transduction pathways could help to better understand the pathogenesis of some particular viral strains

The interferon (IFN) system forms an essential part of the innate immune response, up-regulating hundreds of IFN-stimulated genes (ISGs) in response to viral infection. A key protein in this response is the human myxovirus resistance protein MxA, an IFN-induced GTPase with broad-spectrum antiviral activity, capable of inhibiting many RNA and DNA viruses. One of the most studied antiviral effects of MxA is the inhibition of influenza A virus replication, yet the molecular mechanism of antiviral activity is still unknown. Influenza A viruses are inhibited by MxA at two distinct stages of viral replication; during viral entry and following primary transcription of viral mRNAs. The antiviral effects of MxA during viral entry are highly dependent on IFN, however activity exerted after primary transcription can occur in the absence of IFN. This study provides evidence that MxA exerts its antiviral activity at these two stages of viral replication through distinct mechanisms, and outlines a potential model of MxA antiviral activity following primary transcription. A potential third antiviral mechanism of MxA is proposed based on the findings that MxA is able to regulate cellular lipid metabolism, thereby potentially affecting virion composition. Mutational analysis of MxA highlights the significance of GTPase activity to the antiviral effects of MxA, while also demonstrating that natural single nucleotide polymorphisms in MxA have the potential to severely impair or prevent antiviral activity. Finally, this thesis shows for the first time that MxA exhibits antiviral activity against influenza B viruses. Overall this thesis provides new information illustrating how MxA provides potent antiviral activity against influenza viruses. Such information is vitally important as understanding the molecular basis of how proteins such as MxA function against many human pathogens is fundamentally important in our efforts to create better long-term treatment options for all viral diseases.

Influenza is an important respiratory pathogen that infects several million people each year. Currently available flu vaccines have to be updated regularly in order to be effective as the virus changes its composition by antigenic drift and shift. Most of the antibody response generated by these vaccines is strain specific as it is directed against the head domain (HA1) of HA. The HA2 subunit of hemagglutinin is highly conserved and immunogens designed from this subunit are likely to provide protection against multiple strains of the virus. However, expression of HA2 alone in the absence of HA1 resulted in a protein that took up the low pH conformation of HA. Our goal was to design immunogens from HA2 that would fold into the neutral pH form. Sequence analysis of a large number of HA protein sequences was carried out to identify conserved and exposed regions on HA. Several peptide and protein constructs were designed from the stem region of HA. These proteins were expressed in bacteria and purified proteins were used to immunize mice. Immunized mice were challenged with a lethal dose of virus to test for efficacy of the immunogen. Using this approach, stem domain constructs of HA were successfully designed and shown to take up the neutral pH form. These immunogens were also shown to be capable of providing broad range protection. Residues involved in the low pH induced conformational change of HA were identified from studies on HA2 derived peptides.

Influenza is a major concern across healthcare environments. Annual vaccination of healthcare workers (HCWs) remains essential for maintaining the health and availability of HCWs, as well as influenza prevention in healthcare environments. Yet, annual vaccination coverage among HCWs continues to be below recommended standards during pandemic (pH1N1) and non-pandemic (sINFLU) influenza seasons. The primary aim of this research is to inform the design and implementation of effective HCW targeted influenza vaccination campaigns via a 1) systematic review of the existing literature on HCW pH1N1 vaccination, 2) qualitative content analysis of motivators and barriers to HCW pH1N1 and sINFLU vaccination, as well as 3) quantitative regression analysis of modifiable factors predicting pH1N1 and sINFLU vaccination. The qualitative and quantitative analysis processes were applied to data collected from a large-scale multi-professional sample of HCWs. Findings from all analysis sections were found to be consistent. Most attitudes, beliefs, motivators, and barriers influencing HCW influenza vaccination were similar for pH1N1 and sINFLU vaccinations. Yet, a number of notable differences were also identified. HCWs were likely to accept vaccination if they perceived, 1) vaccination to be safe, 2) vaccination to be protective against influenza for self, loved ones, patients or communities, and 3) influenza to be a serious and severe infection to self and others. Additionally, encouragement from supervisors and colleagues, physicians, and loves ones also enhanced vaccine uptake. Most HCWs avoided vaccination because of 1) limited knowledge or misinformation about vaccination, 2) concern for vaccine induced side-effects and 3) assuming vaccination was not a requirement for healthy adults. With respect to pH1N1 vaccination, mass media communications, perceptions of novel vaccinations, and rapid vaccine development processes especially deterred HCW pH1N1 vaccination. Future vaccination programs targeting HCWs should look towards influencing HCWs’ vaccination attitudes and promoting pro-vaccination cultures in healthcare workplaces.

Le virus de l'Influenza A est l'agent étiologique des épidémies de grippe saisonnière. Ce virus a développé des stratégies complexes pour exprimer ses protéines dans les cellules hôtes dès 4 heures après infection. Au départ de cette étude, je me suis intéressé aux événements intervenant dans l'initiation de la traduction des ARN messagers viraux. L'infection par le virus de l'Influenza A perturbe profondément la physiologie cellulaire, et notamment les processus d'expression des gènes au niveau des étapes de transcription, maturation et export des ARN messagers. De ce fait, j'ai donc commencé par développer les outils permettant de m'affranchir de ces événements nucléaires pour pouvoir me focaliser sur les mécanismes viraux spécifiques de l'initiation de la traduction. Ainsi, j'ai conçu et élaboré un nouveau système de traduction in vitro qui dérive du lysat de réticulocytes de lapin dans lequel sont ajoutés des ribosomes isolés de cellules en culture. Ce lysat, dit hybride, présente l'avantage d'être très efficace pour la production de protéines tout en conservant les caractéristiques traductionnelles des cellules dont les ribosomes dérivent. Le second volet de mes travaux porte sur le rôle de la protéine virale NS1 au niveau de la traduction cellulaire et virale. En combinant des infections virales avec des expériences in vitro et ex-vivo, par transfection d'ARN, je montre que NS1 est capable de stimuler la synthèse protéique des ARNm cellulaires et viraux. Par de la mutagénèse dirigée sur cette protéine de 230 acides aminés, j'observe que la région amino-terminale de la protéine (aa 1-81) est responsable de cet effet activateur. Des mutations ponctuelles au sein de ce domaine révèlent l'importance de deux résidus aminés (R38 et K41) dans la stimulation. En résumé, ces travaux ont permis de mettre au point un nouveau système d'expression in vitro et de mieux comprendre comment est contrôlée la synthèse des protéines virales du virus Influenza A / Influenza A belongs to the orthomyxoviridae family and is the causal agent for the seasonal and epidemic Influenza infections. This virus has developed complex strategies to utilize the host cell protein apparatus for viral protein expression. In this study, I have focused on the events involved during the initiation of translation of viral mRNAs. Influenza A infection profoundly disrupts host cell gene expression mainly at the level of transcription, maturation and mRNA export. As such, it is quite difficult to investigate directly translational control of Influenza. Therefore, I have started my project by elaborating experimental tools that can be used for this purpose. This was done by designing and developing a new in vitro translation system derived from the rabbit reticulocyte lysate which is supplemented with exogeneous ribosomes that have been isolated from different cell types. This lysate, called hybrid system, offers the advantage to be very effective in the production of proteins while maintaining the translational characteristics of the cells from which the ribosomes originate. The second part of my work focusses on the role of the viral NS1 protein on cellular and viral translation. By using an experimental approach based on viral infections together with in vitro and ex vivo translational assays, I could show that NS1 is able to stimulate both viral and cellular protein synthesis. Then, the introduction of deletion mutants of this 230 amino acids protein revealed that its amino-terminal domain (aa 1-81) was responsible for this stimulatory effect (aa 1-81). Finally, the introduction of point mutations in this region showed the importance of two conserved positively charged residues (R38 and K41) for stimulation. In summary, these studies have yielded a new in vitro translation expression system and have shed light on how viral proteins synthesis is regulated by Influenza A virus

L’empaquetage des huit segments du génome des virus influenza de type A est une des étapes clef du cycle viral. Il intervient également dans l’apparition de virus réassortants, les virus pandémiques par exemple, ce qui en fait un enjeu fondamental de la recherche actuelle.Nous avons étudié ce mécanisme au cours de deux études, la première portant sur les vaccins antigrippaux (réassortiment), la seconde visant à construire un virus vecteur (incorporation d’un segment hétérologue). Les semences vaccinales sont obtenues par co-infection d’oeufs de poule embryonnés avec deux souches virales une donneuse (souche circulante de référence) et une accepteuse (A/Puerto Rico/8/34 (H1N1) (PR8)). L'analyse de la composition génétique de treize semences vaccinales H3N2 montre que le segment PB1 de la souche donneuse est présent dans plus de 50 % des semences analysées et qu’une grande variété de réassortants,allant de 6:2 à 2:6 (PR8:H3N2), peut résulter de ces coinfections. Des expériences de compétition d'encapsidation de segments à l’aide de la génétique inverse révèlent que l'encapsidation sélective du segment PB1 dépend de son environnement génétique notamment l’origine virale des segments HA et NA. La seconde partie de mon travail de thèse a été consacrée à la construction d’un vecteur réplicatif sur la base d’un virus influenza H3 naturel sans segment NA. Aucune des constructions contenant le transgène gfp n’a été incorporée dans les particules virales, contrairement à ce qui a été décrit dans la littérature. Bien que les mécanismes moléculaires régissant l’incorporation des segments des virus influenza A demeurent très complexes, le fond génétique semble être déterminant pour ce processus. / The packaging of the eight segments corresponding to the influenza A viruses genomeis a key process of the viral replication as well as a stake of actual scientific researchesbecause it leads to reassortant viruses, e.g. pandemic viruses. We studied the two main facetsof influenza segment packaging: reassortment, during vaccine seeds production and foreignsegment incorporation for influenza vector construction. Vaccine seeds are produced bycoinfection of hens’ eggs with two viruses, a donor one (reference circulating strain) and anacceptor one (A/Puerto Rico/8/34 (H1N1) (PR8)). Analysis of internal genetic composition ofthirteen H3N2 vaccine seeds reveals that PB1 segment of H3N2 donor strain is incorporatedin more than fifty per cent of the cases. Moreover, coinfection events lead to an extremelywide range of reassortants from 6:2 to 2:6 (PR8:H3N2). Segment incorporation competitionassays performed using plasmid-based reverse genetics show that selective packaging of PB1segment is based on genetic environment, i.e. viral origin of HA and NA segments. Thesecond part of my PhD work has been devoted to replicative influenza vector based on H3virus isolated from patients without NA segment at the native stage. None of the gfptransgenic constructions containing reporter gene have been incorporated in viral particles,contrary to literature studies performed using H1N1 laboratory-adapted strains. Even ifmolecular mechanisms controlling influenza A viruses segments incorporation remain stillcomplex, genetic background seems to be an essential element which must be considered withinterest.

A influenza suína (IS) é uma doença altamente contagiosa, de curso rápido e pronta recuperação, causada pelo vírus Influenza tipo A (VIS). Os principais sinais clínicos são tosse, febre, anorexia e baixo desenvolvimento. A doença está presente em outros países e, geralmente, está associada com outros agentes infecciosos. Porém, no Brasil, a sua primeira descrição ocorreu em 2011 e foi associada ao vírus H1N1 pandêmico (pH1N1). O principal objetivo deste estudo foi caracterizar as alterações histológicas mais importantes em casos de doença respiratória suína sugestiva de IS e estudar a associação dessas alterações com os resultados de imuno-histoquímica (IHQ) anti-vírus da influenza A (VIA), anti-circovírus suíno tipo 2 (PVC2) e anti-vírus da síndrome reprodutiva e respiratória suína (PRRSV). Para tanto, foram estudadas 60 amostras de pulmões suínos selecionadas dos materiais do arquivo do Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS), de casos de doença respiratória remetidos no período de 2009 a 2010 e que apresentavam alterações histopatológicas compatíveis com pneumonia viral causada pelo VIS. Trinta e uma amostras (52%) foram provenientes do estado do Rio Grande do Sul, 14 (23%) do Paraná, 11 (18%) de Santa Catarina e quatro (7%) do Mato Grosso do Sul. A IHQ para IA confirmou a presença do agente viral em 45% das amostras analisadas. Os achados histológicos mais significativos associados à IHQ positiva para IA foram bronquiolite necrótica, atelectasia, broncopneumonia purulenta e hiperemia. Por outro lado, as alterações histológicas dos pulmões estudados mais significativamente associadas à IHQ negativa para IA foram hiperplasia dos pneumócitos tipo II, estruturas alveolares e bronquiolares similares a pólipos, hiperplasia de tecido linfoide associado a brônquios (BALT) e pleurite, que são alterações associadas a processos crônicos. Somente dois casos apresentaram marcação positiva na IHQ para PCV2 e nenhum pulmão foi positivo para PRRSV. Esses resultados sugerem que as lesões histológicas encontradas no presente estudo foram compatíveis com as causadas pelo VIS. Os casos negativos de IHQ para IA (55%) podem ser explicados pela baixa frequência do antígeno viral nos tecidos estudados. Como o curso da doença é muito rápido, o teste de IHQ é mais indicado para diagnóstico no início da infecção. Este estudo evidenciou novas alterações em amostras de pulmões de suínos com problemas respiratórios enviadas para o SPV UFRGS a partir de 2009, com ênfase para bronquiolite necrótica, e reforça a importância do estudo histopatológico dos casos de campo para auxiliar na monitoria da sanidade dos rebanhos. / Swine influenza is caused by swine influenza type A virus (SIV). It is a highly contagious disease with a rapid course and recovery. The main clinical signs are cough, fever, anorexia and poor performance. Usually, it is associated with other infectious agents in many countries; however, it has not been described yet in Brazil. The first report of pandemic H1N1 influenza A virus in Brazilian swine herd occurred in 2011. The main aim of this study was to characterize histological features in association with immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) from lung samples from 60 pigs with lesions suggestive of viral pneumonia and collected during the period 2009-2010 and diagnosed at the Setor de Patologia Veterinária of Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil. All the pigs in this study had clinical respiratory disease. Sample distribution was 31 (52%) from Rio Grande do Sul, 14 (23%) Paraná, 11 (18%) from Santa Catarina State and four (7%) from Mato Grosso do Sul State. Positive anti-IA IHC was observed in 45% of the cases and was associated with necrotizing bronchiolitis, atelectasia, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiole polyp-like structures, BALT (bronchus-associated lymphoid tissue) hyperplasia and pleuritis were the significant features of negative samples by anti-IA IHC, which were associated with chronic lesions. Only two cases were positive to PCV2 and none to PRRSV, supports the hypothesis that SIV was the viral agent infecting swine’s lungs. Negative IHC to IA (55%) cases could be explained due to the absence of viral antigens associated with the rapid progress of SI; hence, IHC should be requested in the beginning of the infection. This work has shown how important a careful histological evaluation should be done in order to give the diagnosis. Since 2009, a new histological feature of swine pneumonia from animals with respiratory clinical sign has been observed at samples submitted to SPV-UFRGS. In addition, these results described here proved the importance of histological evaluation in swine herd health management.