Les maladies infectieuses posent un problème majeur de santé publique à travers le monde. En effet, les maladies infectieuses étaient la cause en 2004 de près de 15 millions de décès, que ce soit pour des pathogènes émergents, des pathogènes connus de l’homme depuis de nombreuses années ou encore des pathogènes ré-émergents (Estimation 2004 de l’OMS). Ce nombre a diminué. Cette évolution à la baisse touche la plupart des maladies infectieuses, mais une augmentation reste du domaine du possible comme l’a démontré la récente épidémie d’Ebola. Pour lutter contre ces maladies infectieuses, de nombreux outils de surveillance épidémiologique ont vu le jour à travers le monde. Ces systèmes ont pour but de détecter et d’identifier le plus précocement possible des évènements épidémiques favorisant l’alerte auprès des autorités compétentes et la mise en place de contre-mesures. L’objectif de notre travail a été de construire et de développer un système de surveillance épidémiologique à partir des données de laboratoire de microbiologie de la région Provence-Alpes Côte d’Azur (PACA). Ce système doit nous permettre d’identifier de possibles évènements anormaux de façon hebdomadaire à partir des données des différents laboratoires participants. Le système de surveillance nous a par la suite permis de déclarer plusieurs alertes auprès de l’Agence Régionale de Santé (ARS) PACA, de valoriser notre travail par des publications et enfin de valoriser le travail des laboratoires en leur transmettant une rétro-information contenant les principales alarmes de la semaine. / Infectious diseases are a major public health problem worldwide. Indeed, infectious diseases were the cause in 2004 to nearly 15 million deaths, whether for emerging pathogens, pathogens known to man for many years or even re-emerging pathogens (2004 Estimation of WHO). It has fallen since we moved, for example, 1.27 million cases of malaria in 2004 to 854,600 in 2013. This downward trend affecting most infectious diseases, but an increase is still the realm of possibility as the demonstrated by the recent outbreak of Ebola.To fight against these infectious diseases, many epidemiological surveillance tools have emerged worldwide. These systems are designed to detect and identify as early as possible of possible epidemic events to promote the warning to the competent authorities and the establishment of counter-measures. The objective of our work was to build and develop an epidemiological surveillance system from the microbiology laboratory data of the Provence-Alpes Côte d'Azur (PACA). This system should enable us to identify possible abnormal events weekly data from the different participating laboratories. The monitoring system has enabled us later to declare several warnings from the Regional Health Agency (ARS) PACA, enhance our work through publications and finally to promote the work of laboratories by providing them a feedback containing the main alarms of the week.The development and automation of the system through the creation of an IT platform developed within the Mediterranean Institute University Hospital Infection (IHU) and by increasing the number of participants and the extension of this system to other regions in France or other countries.

The thesis is presented in alternative format, meaning that the results of the thesis take the form of three journal articles, each telling a distinct story within the subject matter, but collectively highlighting the sensitivity of bands to frictional and diabatic processes. Paper 1 is an idealised-modelling study with the Weather Research and Forecasting (WRF) model, in which moist baroclinic waves are simulated from an initial zonally uniform mid-latitude jet on an f-plane at 20-km grid spacing, and the sensitivity of the resulting precipitation bands is explored. Paper 2 employs further WRF idealised-baroclinic-wave simulations and takes a simulation from Paper 1, after the cold front has formed, as the initial condition. A nested domain at 4-km grid spacing is inserted when this simulation is re-initialised to invesigate the sensitivity of finer-scale precipitation cores along the surface cold front. In both Papers 1 and 2, friction and latent-heat release enhance multiple banding at the two distinct horizontal scales, while surface fluxes hinder multiple banding. Paper 3 studies post-frontal snowbands over the English Channel and Irish Sea during extreme cold-air outbreaks in the winters of 2009-10 and 2010-11, via a climatology of precipitation-radar, sounding, and SST data, and real-data WRF sensitivity simulations of one such band over the English Channel. The observational and modelling results show that strong winds and large differential heat fluxes between land and sea were necessary to generate banded precipitation. Coastal orography and the land-sea frictional contrast aided the morphology of bands, but banded precipitation did still form in the absence of these influences in the sensitivity simulations. These three studies and the thesis as a whole highlight the role of frictional and diabatic processes in modifying various types of precipitation bands within baroclinic waves, and in generating bands that would otherwise not exist.

Bakgrund: Smittsamma sjukdomar kan spridas på många sätt, och vissa sjukdomar har egenskapen att de sprids snabbt och orsakar sjukdomsutbrott. Vid utbrott av smittsamma sjukdomar behövs sjuksköterskor för att vårda patienter, ofta under ansträngande förhållanden. En miljö där sjuksköterskan själv riskerar att smittas medför nya utmaningar för henne. Syfte: Studien hade till syfte att undersöka sjuksköterskors erfarenheter av att arbeta patientnära under epidemier och utbrott av mycket smittsamma sjukdomar. Metod: En deskriptiv litteraturstudie utfördes där dataanalysen är en beskrivande syntes av kvalitativa data. Kombinationer av sökord relaterade till sjuksköterskeyrket, smittsamma sjukdomar och kvalitativa studier användes i databasen PubMed för att finna relevant forskning. Slutliga artiklar valdes ut när de bedömts svara mot syftet och vara av kvalitativ karaktär, samtidigt som de svarade mot urvalskriterier som ramar in rätt undersökningsgrupp (sjuksköterskor) och bedömdes vara inriktade mot sjuksköterskornas personliga upplevelser Huvudresultat: Fyra teman och tolv underteman visade sig. De fyra temana som framträdde var 1) Ett närvarande hot, 2) En uttröttad yrkesgrupp, 3) En ständig ovisshet och 4) Ett meningsfullt arbete. Inom ramen för dessa kunde det bland annat ses att rädslan för att sjuksköterskan och hennes familj skulle smittas upplevdes som påtaglig. Samtidigt upplevde de även att arbetet var djupt meningsfullt. Slutsats: Sjuksköterskors negativa erfarenheter av att vårda patienter med smittsamma sjukdomar kretsade kring hotet att smittas, omgivningens syn, en utmattande arbetssituation och omfattande och opålitlig information. Men där fanns också positiva erfarenheter som personlig utvecklig, en stärkt identitet som sjuksköterska och meningsfulla relationer med patienter. / Background: Contagious diseases can be transmitted in many ways. Some spread rapidly and causes disease outbreaks. When disease outbreaks occur in a large scale, nurses is needed for the care of patients, often under strained circumstances. An environment where the nurse risk to get infected herself, brings new challenges to the role.  Aim: The scope of the study was to investigate nurses' experiences of working close to patients during disease outbreaks. Method: A descriptive literature review was performed where data analysis is a descriptive synthesis of qualitative data. Combinations of search terms related to nursing, contagious diseases and qualitative studies where used in database PubMed to find relevant research articles. Finally, articles where chosen when they were assessed to answer the aim of the study and be of qualitative character, while simultaneously targeting nurses and their personal experiences. Main results: Four major themes arose from the study: 1) A present threat, 2) An exhausted workforce, 3) A permanent uncertainty and 4) A meaningful task. Within these themes, it could be seen that the nurses experienced fear of themselves or their family getting the disease, but also that they found their work deeply meaningful. Conclusion: Nurses negative experiences of giving care to patients carrying contagious diseases had many aspects such as the threat to get sick, the view of others, an exhausting work situation and extensive unreliable information. But there were also positive experiences such as personal development, a strengthened identity as a nurse and meaningful relations with patients.

The aim of the study is to investigate how the share prices of food and fashion companies listed on the Stockholm Stock Exchange OMX have changed from when Covid-19 started until end of April 2020, by studying how stock price, volatility and expected return have affected the development of the stock. Using the financial theories of CAPM model and volatility, we investigate how the stock market has developed during the pre-Covid-19 period in comparison to the period when Covid19 is ongoing. Our results show that the volatility increased a lot after the virus burst out and that the expected return changed to higher and more frequent fluctuations. We also compare the two industries showing that the food industry changed less during the post-Covid-19 compared to the fashion industry.

This dissertation consists of three essays examining the impacts of Sanitary and Phytosanitary (SPS) Measures on agricultural trade. The first essay estimates the impact of the 2003 Bovine Spongiform Encephalopathy (BSE) outbreak in the US on Japanese beef imports. I develop a source-differentiated demand system of fresh/chilled and frozen beef imports augmented with endogenous smooth transition functions. Results suggest that over one-half of the estimated income, own-price, and cross-price elasticities reached a new regime in the post-BSE period of Japanese beef imports where the competitive relationship and substitutability between US and Australian beef exports changed significantly. The second essay develops a product-line structural gravity model to estimate the trade flow effects of SPS measures that have been flagged as specific trade concerns in the World Trade Organization's (WTO's) SPS Committee meetings for the top 30 agricultural trading countries covering four major product sectors. Our findings are striking and call attention to the need for a deeper understanding of the impacts of SPS measures on WTO members' agricultural trade. Results show that the trade effects of SPS trade concern measures reduce exporters' agricultural trade by 67%, on average, during periods in which concerns were active. Significant heterogeneity in the trade effect of SPS measures exists with average estimated ad valorem equivalent tariffs ranging from 33% to 106%. The AVE effect of SPS concern measures maintained by the US is estimated at 42%, less than a half (a third) of the AVE effects of SPS concern measures imposed by the European Union (China). China's restrictions on Avian Influenza and ractopamine restrictions in pork exports are estimated to be the most prohibitive, causing an AVE effect of 120.3% and 88.9%, respectively. The third essay develops a discrete-time duration model to examine the extent to which these SPS concern measures affect the hazard rate of US agri-food exports during the 1995-2016 period. Results show that SPS concern measures raise the hazard rate of US agri-food exports by a range of 2.1%~15.3%, causing the predicted hazard rate to increase from 21.8% to a range of 23.6%~27.9%. This effect is heterogeneous across different agricultural sectors, with the most substantial effects occurring in US exports of meat, fruits, and vegetables. / Doctor of Philosophy / This dissertation consists of three essays on the examination of Sanitary and Phytosanitary (SPS) Measures and their impacts on agricultural trade. The first essay estimates the impact of the US 2003 Bovine Spongiform Encephalopathy (BSE) outbreaks on Japanese beef imports. Using a source-differentiated demand system of fresh/chilled and frozen beef imports embedded with endogenous smooth transition functions, we find that over one-half of the estimated income, own-price, and cross-price elasticities have changed remarkably, causing the Japanese beef import market to reach a new regime in the post-BSE period where the substitution and/or competition relationships between the US and Australia have changed. The second essay develops a product-line structural gravity model to estimate the trade effects of SPS measures flagged as concerns in the WTO's SPS Committee meetings for the top 30 agricultural trading countries covering four major product sectors. Results show that the trade effects of SPS concern measures are negative and significant, with the average estimated AVE tariffs ranging 33%~106%. The AVE effect of SPS concern measures maintained by the US is estimated to be 42%, less than a half (a third) of the AVE effects of SPS concern measures imposed by the European Union (China). China's restrictions on Avian Influenza and various ractopamine restrictions in the production and export of pork products are estimated to be the most prohibitive, causing an AVE effect of 120.3% and 88.9%, respectively. The third essay applies a discrete-time duration model to examine the extent to which SPS concern measures affect the hazard rate of US agri-food exports in 1995-2016. Results show that SPS concern measures raise the hazard rate of US agri-food exports by a range of 2.1%~15.3%, causing the predicted hazard rate to increase from 21.8% to a range of 23.6%~27.9%. This effect is heterogeneous across different agricultural sectors, with the most substantial effects occurring in US exports of meat, fruits, and vegetables.

Tesis por compendio / [EN] Legionella pneumophila is a strictly environmental and opportunistic pathogen that can cause severe pneumonia after inhalation of aerosols with enough bacterial load. Outbreaks and sporadic cases are usually localized in temperate environments, and the reservoirs are often water-related sources where biofilms are created. The existence of non-cultivable forms of the bacteria increases the risk for public health, as culture-based methods may miss them, thus complicating the environmental investigations of the sources. Genetic classification through the Sequence-Based Typing (SBT) technique allowed an increased discrimination among L. pneumophila strains compared to previous methods. SBT data can also be used for genetic variability and population structure studies, but a more exhaustive analysis can be performed using high-throughput genome sequencing strategies. This thesis describes the use of both SBT and genomic sequencing to evaluate and provide solutions to different public health needs in L. pneumophila epidemiology. We have focused in the Comunidad Valenciana (CV), the second region in Spain with the highest incidence of Legionellosis, with special interest in the city of Alcoy, where recurrent outbreaks have occurred since 1998. Firstly, SBT data were used to gain a deeper insight into the genetic variability and distribution of the most abundant Sequence Types (ST) in the CV area. We have shown that the level of variability in this region is comparable to that from other countries, revealing the existence of both locally and broadly extended profiles. Approximately half of the observed genetic diversity was found to result from geographical and temporal structure. Secondly, L. pneumophila detection from environmental sources remains a challenge for public health. A comparison between water and biofilm samples using a sensitive touchdown PCR (TD-PCR) strategy revealed that the use of biofilms increased by ten-fold the detection rate. This method allowed evaluating the hidden uncultivable L. pneumophila diversity in the locality of Alcoy and the real-time investigation of a Legionellosis outbreak affecting a hotel in Calpe (Southeast of Spain) in 2012. Thirdly, genomic sequencing was applied to a set of 69 strains isolated during 13 outbreaks occurred in Alcoy in the period 1999-2010, mainly the recurrent ST578. Higher intra-outbreak variability than expected was observed, pointing to the potential existence of multiple sources in this endemic area or high environmental diversity. Interestingly, above 98% of the genomic variability in this ST was found as being incorporated through recombination processes rather than through point mutations. Finally, a metagenomic analysis of environmental biofilms from Alcoy revealed a microbial community dominated by Proteobacteria, Cyanobacteria, Actinobacteria and Bacteroidetes. Despite the known endemism of Legionella in this area, the genus was only found in a relative abundance ranging 0.01-0.07%, which explains the low recovery from environmental sources. In summary, the results from this thesis can benefit public health efforts to control this pathogen in the environment, as we provide new insight into its molecular epidemiology, with immediate applications to surveillance and outbreak investigations. / [ES] Legionella pneumophila es un patógeno oportunista estrictamente ambiental capaz de causar neumonía debido a la inhalación de aerosoles con suficiente carga bacteriana. Los brotes y casos esporádicos suelen producirse en ambientes templados y los reservorios encontrarse en zonas con agua donde pueden crearse biopelículas microbianas. La existencia de formas no cultivables de la bacteria aumenta el riesgo para la salud pública, ya que los métodos estándar basados en cultivo microbiológico no pueden detectarlas, complicando las investigaciones ambientales. La clasificación genética basada en el método Sequence-Based Typing (SBT) permite un mayor poder de discriminación entre cepas de L. pneumophila en comparación con métodos previos. Los datos derivados del SBT pueden utilizarse para estudios de variabilidad genética y estructura poblacional. Sin embargo, puede llevarse a cabo un análisis más exhaustivo mediante técnicas de secuenciación genómica de alto rendimiento. Esta tesis describe la utilización tanto de SBT como de secuenciación genómica para evaluar e incluso proponer soluciones a diferentes necesidades en salud pública relacionadas con la epidemiología de L. pneumophila. Nos centramos en la Comunidad Valenciana (CV), la segunda región en España con mayor incidencia de Legionelosis, con especial interés en la localidad de Alcoy, donde ocurren brotes de forma recurrente. En primer lugar, utilizamos datos derivados de SBT para conocer mejor la variabilidad y la distribución de los perfiles genéticos (Sequence Types, ST) en el área de la CV. Mostramos que el nivel de variabilidad en sólo esta región es comparable a la de otros países, con perfiles extendidos local y globalmente. Aproximadamente la mitad de la diversidad genética observada se estima que procede de estructuración geográfica y temporal. En segundo lugar, la detección de L. pneumophila a partir de fuentes ambientales sigue suponiendo un reto para la salud pública. En esta tesis realizamos una comparación entre la detección mediante touchdown PCR (TD-PCR) a partir de muestras de agua y biopelículas microbianas y mostramos que estas últimas proporcionan un aumento de 10 veces en la tasa de detección de la bacteria. Este método permitió evaluar la diversidad no cultivable de L. pneumophila en la localidad de Alcoy y la investigación a tiempo real de un brote en un hotel en Calpe (Sudeste de España) en 2012. A continuación, aplicamos la secuenciación genómica a 69 cepas aisladas durante 13 brotes ocurridos en Alcoy en el período 1999-2010, principalmente el recurrente ST578. Se observó mayor variabilidad entre cepas de un mismo brote que la esperada, lo cual apunta a la existencia potencial de múltiples fuentes en este área, o alta diversidad ambiental. Además, se observó que más del 98% de la variabilidad genómica fue introducida por procesos de recombinación y no de mutación puntual. Finalmente, se realizó un análisis metagenómico de biopelículas ambientales recogidas en Alcoy. Se encontró que la comunidad está dominada por Proteobacteria, Cyanobacteria, Actinobacteria y Bacteroidetes. A pesar del conocido endemismo de Legionella en el área, este género sólo se encontró en una abundancia relativa entre 0.01-0.07%, lo cual explica su baja tasa de recuperación a partir de muestras ambientales. En resumen, los resultados de esta tesis pueden ser de utilidad para los programas de control de este patógeno llevados a cabo por las autoridades de salud pública, ya que proporcionan una nueva percepción de su epidemiología molecular, con aplicación inmediata a la vigilancia e investigación de brotes. / [CA] Legionella pneumophila és un patogen oportunista estrictament ambiental capaç d'ocasionar pneumònia degut a la inhalació d'aerosols amb la suficient carga bacteriana. Els brots i casos esporàdics solen ocórrer en ambients temperats, i els reservoris solen trobar-se en zones amb aigua on poden crear-se biopel·lícules microbianes. La existència de formes no cultivables del bacteri augmenten el risc per a la salut pública, ja que els mètodes estàndard basats en el cultiu microbiològic no poden detectar-les, complicant les investigacions ambientals. La classificació genètica basada en el mètode Sequence-Based Typing (SBT) permet un major poder de discriminació entre soques de L. pneumophila en comparació amb previs mètodes. Les dades derivades del SBT poden utilitzar-se per a estudis de variabilitat genètica i estructura poblacional, però un anàlisis més exhaustiu pot dur-se a terme a través de tècniques de seqüenciació genòmica d'alt rendiment. Esta tesis descriu la utilització tant del SBT com de la seqüenciació genòmica per a avaluar i proposar solucions a diferents necessitats en salut pública relacionades amb l'epidemiologia de L. pneumophila. Ens centrem en la Comunitat Valenciana (CV), la segona regió d'Espanya amb la major incidència de Legionel·losi, amb especial interès en la localitat d'Alcoi, on els brots ocorren de forma recurrent des de 1998. Primer, hem utilitzat dades derivades del SBT per a conèixer millor la variabilitat i la distribució dels perfils genètics (Sequence Types, ST) en l'àrea de la CV. Mostrem que el nivell de variabilitat en només aquesta regió és comparable a la d'altres països, amb perfils estesos tant de forma local com més amplia. Aproximadament la meitat de la diversitat genètica observada s'estima que procedeix d'estructuració geogràfica i temporal. Segon, la detecció de L. pneumophila a partir de fonts ambientals continua suposant un repte per a la salut pública. En aquesta tesis realitzem una comparació entre la detecció mitjançant touchdown PCR (TD-PCR) a partir de mostres d'aigua i biopel·lícules microbianes i mostrem que aquestes últimes proporcionen un augment de deu vegades en la tassa de detecció. A més, aquest mètode ens va permetre avaluar la diversitat no cultivable de L. pneumophila a la localitat d'Alcoi i la investigació a temps real d'un brot de Legionelosis que va afectar a un hotel en Calp (Sud-est d'Espanya) a l'any 2012. Tercer, vam aplicar la seqüenciació genòmica a 69 soques aïllades durant 13 brots ocorreguts a Alcoi en el període 1999-2010, principalment el recurrent ST578. Es va observar una major variabilitat entre soques d'un mateix brot de l'esperada, apuntant a l'existència potencial de múltiples fonts en aquesta àrea, considerada endèmica, o alta diversitat ambiental. A més, es va observar que més del 98% de la variabilitat genòmica havia sigut introduïda a partir de processos de recombinació i no de mutació puntual. Finalment, es va realitzar una anàlisi metagenòmica de biopel·lícules ambientals recollides a Alcoi. Varem trobar que la comunitat està dominada per Proteobacteria, Cyanobacteria, Actinobacteria i Bacteroidetes. A pesar del conegut endemisme de Legionella en l'àrea, aquest gènere només es va trobar en una abundància relativa entre 0.01-0.07%, el qual explica la seua baixa tassa de recuperació a partir de mostres ambientals. En resum, els resultats d'aquesta tesi poden ser d'utilitat per als programes de control d'aquest patogen duts a terme per les autoritats de salut pública, ja que proporcionen una nova percepció de la seua epidemiologia molecular, amb aplicació immediata a la vigilància i la investigació de brots. / Sánchez Busó, L. (2015). Genetic and genomic variability of Legionella pneumophila: applications to molecular epidemiology and public health [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/52854 / Premios Extraordinarios de tesis doctorales / Compendio

Yes / Enteropathogenic Escherichia coli (EPEC) is usually associated with outbreaks and sporadic cases of severe infantile diarrhoea in the developing world, and less commonly with sporadic cases in developed countries. Very little evidence indicates that EPEC is a food-borne pathogen for adults. In a previous study, two groups of adult travellers became ill, and eae+ E. coli of serogroup O111 was isolated from affected individuals and epidemiologically linked to food consumption. Here the strain responsible was further investigated and characterized as an unusual atypical EPEC. PCR analysis of the designated type isolate showed the presence of the rorf1 and espB genes of the LEE pathogenicity island, which was inserted at the chromosomal selC locus. The isolate was negative for the enteroaggregative E. coli EAST-1 toxin present in other strains of EPEC associated with food-borne outbreaks. The strain adhered sparsely to HEp-2 cell monolayers in a diffuse manner, but fluorescent actin staining demonstrated that it was capable of inducing polymerization of actin at the sites of bacterial attachment. Strain P2583 is the first EAST-negative EPEC to be confirmed as a cause of outbreaks of infection in adults following the consumption of contaminated food or water.

Salmonellosis, a significant foodborne illness in humans, is caused by Salmonella, with poultry and poultry products acting as significant reservoirs and sources of human infection. Salmonella enterica subspecies enterica serotype Reading has recently emerged as a notable foodborne pathogen responsible for extensive multistate human outbreaks in North America. This study focused on evaluating the capacity of the emerged serotype to colonize broiler breeder reproductive tissues and potentially contaminate eggs, indicating the potential for vertical transmission. For this investigation, two Salmonella Reading strains were utilized, one associated with outbreaks and another non-outbreak strain. Both strains were initially modified with bioluminescent marker genes to facilitate tracking post-experimental infection in broiler breeders. The results indicated that both strains could colonize the reproductive tract of infected hens and be transmitted vertically through the eggs. This finding enhances our understanding of the colonization and vertical transmission capabilities of this serotype in broiler breeders.

范家偉. / 論文(博士)--香港中文大學歷史學部, 1997. / 附參考文獻. / 中英文摘要. / Available also through the Internet via Dissertations & theses @ Chinese University of Hong Kong. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Fan Jiawei. / Lun wen (Bo shi)--Xianggang Zhong wen da xue li shi xue bu, 1997. / Fu can kao wen xian. / Zhong Ying wen zhai yao.

A influenza ou gripe é uma doença aguda do sistema respiratório, de alta transmisssibilidade e presente em todo o mundo. Os vírus influenza A tem freqüente capacidade de mutação antigênica, podendo assim causar epidemias sazonais e pandemias com repercussão social e econômica. O objetivo deste estudo foi descrever a pandemia de influenza pelo vírus A(H1N1)pdm09 no Brasil. Foi desenvolvido um estudo descritivo, nos anos de 2009 e 2010. Utilizou-se como fonte de dados os casos notificados no SINAN, módulo influenza pandêmica e da declaração de óbito do SIM. Foram calculadas medidas de frequência, medida de tendência central e medidas de dispersão. O projeto foi aprovado pelo Comitê de Ética em Pesquisa da FM-USP. Foram notificados no SINAN 105.054 casos suspeitos de influenza A(H1N1)pdm09. Destes, 53.797 (51,20%) foram encerrados como influenza por novo subtipo viral. Entre os casos confirmados, 56,73% eram do sexo feminino. A média de idade dos confirmados foi de 26,31 (dp ± 18,10) anos. O período mais freqüente de início de sintomas compreende as SE 31 a 34 de 2009. A febre foi o sinal mais freqüente entre os confirmados (99,74%) e a presença de comorbidades foi notificada em 32,53% dos casos. Em 2009, foram confirmados casos nos 26 Estados e no Distrito Federal. A incidência de SRAG por influenza na população no ano de 2009 foi de 28,03/100.000 habitantes e em 2010, 0,51/100.000 habitantes. Os estados do PR (301,34), SC (36,00), RS (27,42), RJ (20,12) e SP (19,72) apresentaram as maiores incidências por 100.000 habitantes. Foram hospitalizados 46,42% dos casos confirmados. Evoluíram para cura 47.643 (93,77%) casos. A taxa de letalidade foi de 4,04%. Entre todas as causas de óbitos nos anos de 2009 e 2010, as de doenças do aparelho respiratório correspondem a aproximadamente 10% em cada ano. Após o relacionamento entre os registros, foram identificados 173.063 óbitos que atendiam a definição de SRAG e 5.973 óbitos de casos notificados como influenza pandêmica. Desses, 36,33% foram classificados no SINAN como confirmados para influenza pandêmica. Entre esses confirmados, pelo SINAN, 73,36% evoluíram para óbito por influenza pandêmica e 21,01% foram encerrados como curados. A estimativa de subnotificação de casos no SINAN, partindo do pressuposto da subnotificação de óbitos, foi de 96,55%. Concluiu-se que a pandemia pelo vírus A(H1N1)pdm09 atingiu o Brasil entre abril/2009 e dezembro/2010. As crianças e os adultos jovens foram os mais acometidos. Embora o comportamento epidemiológico da pandemia de influenza no Brasil tenha apresentado predomínio de casos clinicamente leves e com baixa letalidade, os casos de influenza que apresentem os fatores de risco conhecidos para complicações, devem ser acompanhados. As informações dos casos notificados representam apenas os casos captados pelo sistema de vigilância de doenças de notificação compulsória, sendo necessário considerar diferentes fontes de informação para monitoramento epidemiológico e formulação de ações de vigilância e controle. / Influenza or flu is an acute disease of the respiratory system, highly transmissible, and distributed worldwide. Influenza A viruses undergo frequent antigenic shift and may thus cause seasonal epidemics and pandemics with social and economic repercussions. The aim of this study was to describe the pandemic caused by influenza virus A(H1N1)pdm09 in Brazil. A descriptive study was conducted in the years 2009 and 2010. SINAN, the Brazilian Information System for reportable diseases, and SIM, the Brazilian Mortality Information System were the sources of the data used in the study. We calculated measures of frequency, of central tendency and of dispersion. The project was approved by the Ethics Committee of the FM-USP. 105,054 suspected cases of influenza A(H1N1)pdm09 were reported in SINAN. Of these, 53,797 (51.20%) were classified as the new influenza virus subtype. Among the confirmed cases, 56.73% were female. The mean age of confirmed cases was 26.31 (SD ± 18.10) years. The most frequent period of onset of symptoms comprised the weeks 31-34/2009. Fever was the most common sign among confirmed cases (99.74%) and the presence of comorbidities was reported in 32.53% of cases. In 2009 there were confirmed cases in all 26 Brazilian states and the Federal District. The incidence of SARS caused by influenza in the population in 2009 was 28.03/100,000 inhabitants and in 2010, 0.51/100,000 inhabitants. The states of PR (301.34), SC (36.00), RS (27.42), RJ (20.12) and SP (19.72) presented the highest incidence per 100,000 inhabitants. 46.42% of the confirmed cases were hospitalized, 47,643 were cured (93.77%). Among all causes of deaths in the years 2009 and 2010, the respiratory diseases accounted for approximately 10%. After the linkage between the databases, 173,063 deaths that met the definition of SARS cases and 5,973 deaths had been reported as pandemic influenza cases in SINAN. Of these, 36.33% were classified as confirmed cases for pandemic influenza. Among those confirmed by SINAN, 73.36% died due to pandemic influenza and 21.01% had been classified as cured. The estimate of underreporting in SINAN, assuming underreporting of deaths was 96.55%. We concluded that the pandemic virus A(H1N1) pdm09 hit Brazil between April 2009 and December 2010. Children and young adults were the most affected. Although the epidemiological pattern of pandemic influenza in Brazil has shown a prevalence of clinically mild and low lethality cases, cases of influenza presenting the known risk factors for complications, should be followed. The information of the reported cases represents only the cases detected by the surveillance of notifiable diseases system. It is necessary to consider different sources of information for epidemiological monitoring and formulation of strategies for surveillance and control.