<p>Purpose: The purpose with this study is to analyze if the Swedish authorities and media had different ways of discussing the new influenza, in connection with the pandemic classification June 11, 2009. This is the first time an influenza has been classified as a pandemic since the Hongkong-influenza in1968. Methodology: The method used for the study is discourse analysis, aqualitative method that gives the opportunity to study not only what is said, but how things are said. In this thesis, the aim is to study how the image ofthe new influenza is transmitted via the texts. The texts have been analysed based on:- General and underlying themes- Words and concepts used- Persons/sources quoted or referred to- Historical connections/historical backgroundTheoretical perspectives: The study is based on theories about socialconstructionism and discourse analysis. Conclusions: the conclusions drawn from the study show that the media textsare more dramatic and sensational when it comes to describing the newinfluenza. The Swedish authorities have a more fact-based and calming tone towards the public. Within the analyzed material, it is possible to seedifferences between the discourses, also when describing the same themes. Within some themes, resemblances have been identified between the mediadiscourse and the authorithy discourse.</p>

The problem of this study was to review within Dallas and Tarrant Counties the relationship between an "influenza-like" illness within six months prior to contracting Mycobacterium kansasii disease. An interview instrument was developed and used during personal interviews to collect data. Additional data of case rates and reported cases was compiled from local and national governmental public health agencies. Analysis of the data indicated no significant difference between an individual contracting an "influenzalike" illness within six months prior to the acquiring of Mycobacterium kansasii disease. Therefore, there is no relationship between having had influenza-like symptoms within six months of contracting Mycobacteria kansasii.

Purpose: The purpose with this study is to analyze if the Swedish authorities and media had different ways of discussing the new influenza, in connection with the pandemic classification June 11, 2009. This is the first time an influenza has been classified as a pandemic since the Hongkong-influenza in1968. Methodology: The method used for the study is discourse analysis, aqualitative method that gives the opportunity to study not only what is said, but how things are said. In this thesis, the aim is to study how the image ofthe new influenza is transmitted via the texts. The texts have been analysed based on:- General and underlying themes- Words and concepts used- Persons/sources quoted or referred to- Historical connections/historical backgroundTheoretical perspectives: The study is based on theories about socialconstructionism and discourse analysis. Conclusions: the conclusions drawn from the study show that the media textsare more dramatic and sensational when it comes to describing the newinfluenza. The Swedish authorities have a more fact-based and calming tone towards the public. Within the analyzed material, it is possible to seedifferences between the discourses, also when describing the same themes. Within some themes, resemblances have been identified between the mediadiscourse and the authorithy discourse.

This study conducted a framing research that analyzed coverage of the bird flu (avian flu) in China by two major American newspapers that are influential in China (The New York Times and Washington Post). The goal was to examine how these two prestigious newspapers frame the bird flu epidemic in China and how they represent the country in this international health crisis. This study employed textual analysis regarding the way bird flu news articles were framed in terms of problem definition, causal explanation, moral evaluation and solution recommendations in both newspapers. The study found the epidemic was framed as more than just a public health crisis. Multiple news frames were found in both newspapers' coverage of bird flu, depicting the event as a cultural, social and political crisis to the nation and to the world.

From fighting microbial infections to preparing for pandemics, Brett Finlay is discovering how the body's own defenses could boost our chances in the battle against infectious diseases.

This thesis addresses issues related to surveillance for disease in commercial and non-commercial poultry populations. The motivation for this work has largely arisen from the unprecedented outbreaks of highly pathogenic avian influenza (HPAI) H5N1 that have occurred in 52 countries in Asia, Africa and Europe since 2003. A series of studies are presented using data derived from two countries, Vietnam and New Zealand. The two Vietnamese studies provide in-depth epidemiological analyses of the outbreak of HPAI H5N1 from December 2003 to March 2004. The three New Zealand studies deal with issues related to the development of effective surveillance strategies for HPAI — informed both directly and indirectly by the findings from the Vietnamese studies. This approach provides an example of how ‘lessons’ learnt from countries that have experienced large scale infectious disease epidemics can be used to assist in the design of surveillance activities in (as yet) unaffected countries. The descriptive analyses of the 2003 – 2004 outbreak of HPAI H5N1 in Vietnam indicate that the epidemic was seeded simultaneously in the north and south of the country in the later part of 2003 with 87% of provinces affected by February 2004. HPAI risk was concentrated around the Mekong and Red River Deltas. The broad scale spatial distribution of disease is likely to have been associated with regional differences in the poultry farming, trade in poultry, and environmental conditions such as the presence of bodies of water which would support reservoir species for the virus. A Bayesian zero-inflated Poisson regression model was used to quantify the influence of environmental and demographic factors on the spatial distribution of HPAI positive communes. In areas where disease was reported, our results show that HPAI risk was positively associated with the presence of irrigation and negatively associated with elevation. After controlling for these fixed effects, a single large area of elevated risk in the Red River Delta area was identified, presumably arising from similarities in the likelihood of reporting disease or the presence of factors increasing disease transmission and spread. Further investigations to elucidate likely transmission mechanisms, targeting this area of the country, would be a profitable area of future research. The second part of this thesis presents three studies that address issues related to the development of effective surveillance strategies for HPAI in New Zealand. The first was a cross-sectional study to enumerate the prevalence of backyard poultry ownership in two areas (one urban and the other rural) close to a large provincial city in the North Island of New Zealand. The prevalence of poultry ownership was 2% (95% CI 1% – 4%) in the urban area and 19% (95% CI 12% – 30%) in the rural area. The relatively low numbers of land parcels where poultry are present indicates that these areas, in the event of an infectious disease incursion, would be unlikely to pose a risk for spread of infectious agent. A cross-sectional survey of all members of the Poultry Industry Association of New Zealand was conducted in the later half of 2007. Respondents were asked to document contacts made with other enterprises related to feed, live birds and hatching eggs, table eggs and poultry product, and waste litter and manure. Patterns of contact were analysed using social network analyses. Each of the four networks had scale-free properties, meaning that for each movement type there were small numbers of enterprises that had contacts with large numbers of enterprises (potential ‘super-spreaders’ of disease). The presence of an undetected infectious disease in enterprises with super-spreader characteristics increases the likelihood that an epidemic will propagate rapidly through the population, assuming there is a directly proportional relationship between the number of contacts an enterprise makes and the probability that disease will be transferred from one location to another. While the finding that feed suppliers had large numbers of poultry farm contacts in the feed network came as no surprise, what was of greater interest was that there were small numbers of poultry farms that reported off-farm movements of feed. This should serve as an important reminder for disease control authorities: movement (and other) restrictions applied during the course of an animal health emergency should be applied across a range of industry sectors, recognising that some industry participants may practice activities that are not entirely typical for their enterprise type (e.g. poultry farms on-selling feed to other farms). In the absence of perfect and up-to-date network data, knowledge of the characteristics of individual enterprises that render them more likely to be atypical (e.g. size, type, and geographic location) would be of value, since this information could be used to inform a risk based approach to disease surveillance and control. A scenario tree model was developed as an approach for evaluating the effectiveness of New Zealand’s passive surveillance system for HPAI. The model was developed in two stages. In the first, factors thought to influence the geographic distribution of NAI risk of introduction and spread (and therefore surveillance strategy) were combined to create a spatial risk surface. In the second stage, a scenario tree model of the passive surveillance system for NAI was developed using the spatial risk surface and the HPAI surveillance strategy prescribed by Biosecurity New Zealand. The model was most sensitive to farmers reporting the presence of suspected cases of disease. This implies that the sensitivity of the system as a whole stands to increase if the importance of reporting suspicious clinical signs is reiterated to poultry producers. The studies presented in this thesis have presented a range of techniques and methodological approaches that are sufficiently generic to be used in any country to inform the design of surveillance strategies for a variety of animal diseases, not just those of poultry. Although epidemiology, as a discipline, is endoured with a vast range of analytical techniques that can be used to enhance the understanding of factors influencing the spread of disease among animal populations, the quality of data used to support these techniques is often lacking. The challenge in the years ahead, for both developed and developing countries, is to set in place the appropriate infrastructures to collect details of animal populations consistent in quality over time and space.

Eight studies of the epidemiological dynamics of avian influenza viruses were conducted on poultry in Hong Kong, with special focus on the movement of birds through the live poultry marketing system, and the implications for avian influenza transmission. The first involved analysis of virus isolation data from faecal samples obtained from cooperating stalls in live poultry markets in Hong Kong in a routine sampling program undertaken between 1999 and 2001. This showed that two subtypes of avian influenza viruses, H9N2 and H6N1, have become well established in the Hong Kong live poultry markets, especially in chickens (mainly H9N2) and quail (mainly H6N1). In addition, a wave of H5N1 virus infection occurred in 2001 after it had been absent through the earlier period of the study. The second study was an evaluation of long term changes in the marketing systems for live poultry in Hong Kong, their likely effects on avian influenza epidemiology, and documented evidence of the prevalence of various H subtypes of avian influenza in sampling undertaken during three periods from 1975 to 2001. The third project involved two cross-sectional studies and one longitudinal study on local quail farms in Hong Kong. Results showed that quail could act as a reservoir host for H9N2 and H6N1 subtype viruses, but each subtype differed in its epidemiology. H9 virus usually infected quail at around 10 days of age, whereas H6 infected quail at 15-20 days of age. At 35 days of age (usual market age in Hong Kong), a proportion of market quail were likely to be susceptible to H6 (50%) and H9 viruses (20%), and were able to transmit the virus in the markets. Due to these findings, the Hong Kong Government closed the quail farming operations and restricted the sale of quail in live poultry markets. A longitudinal study was conducted on three live poultry market stalls to assess the time from stall entry to sale, and evaluate the influence of this delay on avian influenza virus transmission to other poultry in the same stall. Participating stalls varied from high volume/rapid turnover to low volume/slow turnover. Turnover for tagged poultry was rapid, although some chickens became infected with H9 virus before sale. Birds which stayed longer, such as quail, became infected and maintained infection in the stall. As well as spread by direct contact and on typical fomites, keeping of pet roosters and re-use of washing water were identified as factors increasing the ability of avian influenza strains to persist in market stalls. An experimental replica of a market stall was created to study the transmission of low pathogenic avian influenza virus (H9N2) in a controlled environment, with different rates of population turnover and different immune status with respect to both H5 and H9 subtypes. Transmission was influenced by distance between birds, the proportion of birds carrying antibody to H9 and the rate of introduction of susceptible birds, but not by the use of H5N2 vaccine. In order to assess the effectiveness of temporary depopulation of stalls, a study was conducted to compare the prevalence of avian influenza virus and Newcastle disease virus before and shortly after the monthly rest day in live poultry markets in Hong Kong, by virus isolation. Prevalence of H9N2 avian influenza virus was reduced by the rest day, but Newcastle disease virus prevalence was unaffected. During the 2002 avian influenza H5N1 outbreak in local chicken farms, a case-control study was undertaken to identify risk factors that may have contributed to this outbreak. A questionnaire was administered by interview to collect the data for this study. Multivariate logistic regression models showed that movement of people and fomites from live poultry markets to farms were important influences on transmission, and that the live bird markets were the likely source of virus for farms. A spatial stochastic computer model was constructed to predict the spread of avian influenza virus in local chicken farms and live poultry markets in Hong Kong, and the effectiveness of control measures. The data used in model parameter setting was derived from the case-control study. The reference model produced an epidemic curve which was similar to the true epidemic curve in the 2002 outbreak. Control strategies such as rest day and vaccination were evaluated within the model, and found to produce results comparable with field experience. Results from these studies clarify various aspects of the epidemiological features and transmission dynamics of avian influenza viruses, and provide guidance on appropriate control and prevention strategies for highly pathogenic avian influenza viruses within poultry marketing systems in Asia.

This thesis addresses issues related to surveillance for disease in commercial and non-commercial poultry populations. The motivation for this work has largely arisen from the unprecedented outbreaks of highly pathogenic avian influenza (HPAI) H5N1 that have occurred in 52 countries in Asia, Africa and Europe since 2003. A series of studies are presented using data derived from two countries, Vietnam and New Zealand. The two Vietnamese studies provide in-depth epidemiological analyses of the outbreak of HPAI H5N1 from December 2003 to March 2004. The three New Zealand studies deal with issues related to the development of effective surveillance strategies for HPAI — informed both directly and indirectly by the findings from the Vietnamese studies. This approach provides an example of how ‘lessons’ learnt from countries that have experienced large scale infectious disease epidemics can be used to assist in the design of surveillance activities in (as yet) unaffected countries. The descriptive analyses of the 2003 – 2004 outbreak of HPAI H5N1 in Vietnam indicate that the epidemic was seeded simultaneously in the north and south of the country in the later part of 2003 with 87% of provinces affected by February 2004. HPAI risk was concentrated around the Mekong and Red River Deltas. The broad scale spatial distribution of disease is likely to have been associated with regional differences in the poultry farming, trade in poultry, and environmental conditions such as the presence of bodies of water which would support reservoir species for the virus. A Bayesian zero-inflated Poisson regression model was used to quantify the influence of environmental and demographic factors on the spatial distribution of HPAI positive communes. In areas where disease was reported, our results show that HPAI risk was positively associated with the presence of irrigation and negatively associated with elevation. After controlling for these fixed effects, a single large area of elevated risk in the Red River Delta area was identified, presumably arising from similarities in the likelihood of reporting disease or the presence of factors increasing disease transmission and spread. Further investigations to elucidate likely transmission mechanisms, targeting this area of the country, would be a profitable area of future research. The second part of this thesis presents three studies that address issues related to the development of effective surveillance strategies for HPAI in New Zealand. The first was a cross-sectional study to enumerate the prevalence of backyard poultry ownership in two areas (one urban and the other rural) close to a large provincial city in the North Island of New Zealand. The prevalence of poultry ownership was 2% (95% CI 1% – 4%) in the urban area and 19% (95% CI 12% – 30%) in the rural area. The relatively low numbers of land parcels where poultry are present indicates that these areas, in the event of an infectious disease incursion, would be unlikely to pose a risk for spread of infectious agent. A cross-sectional survey of all members of the Poultry Industry Association of New Zealand was conducted in the later half of 2007. Respondents were asked to document contacts made with other enterprises related to feed, live birds and hatching eggs, table eggs and poultry product, and waste litter and manure. Patterns of contact were analysed using social network analyses. Each of the four networks had scale-free properties, meaning that for each movement type there were small numbers of enterprises that had contacts with large numbers of enterprises (potential ‘super-spreaders’ of disease). The presence of an undetected infectious disease in enterprises with super-spreader characteristics increases the likelihood that an epidemic will propagate rapidly through the population, assuming there is a directly proportional relationship between the number of contacts an enterprise makes and the probability that disease will be transferred from one location to another. While the finding that feed suppliers had large numbers of poultry farm contacts in the feed network came as no surprise, what was of greater interest was that there were small numbers of poultry farms that reported off-farm movements of feed. This should serve as an important reminder for disease control authorities: movement (and other) restrictions applied during the course of an animal health emergency should be applied across a range of industry sectors, recognising that some industry participants may practice activities that are not entirely typical for their enterprise type (e.g. poultry farms on-selling feed to other farms). In the absence of perfect and up-to-date network data, knowledge of the characteristics of individual enterprises that render them more likely to be atypical (e.g. size, type, and geographic location) would be of value, since this information could be used to inform a risk based approach to disease surveillance and control. A scenario tree model was developed as an approach for evaluating the effectiveness of New Zealand’s passive surveillance system for HPAI. The model was developed in two stages. In the first, factors thought to influence the geographic distribution of NAI risk of introduction and spread (and therefore surveillance strategy) were combined to create a spatial risk surface. In the second stage, a scenario tree model of the passive surveillance system for NAI was developed using the spatial risk surface and the HPAI surveillance strategy prescribed by Biosecurity New Zealand. The model was most sensitive to farmers reporting the presence of suspected cases of disease. This implies that the sensitivity of the system as a whole stands to increase if the importance of reporting suspicious clinical signs is reiterated to poultry producers. The studies presented in this thesis have presented a range of techniques and methodological approaches that are sufficiently generic to be used in any country to inform the design of surveillance strategies for a variety of animal diseases, not just those of poultry. Although epidemiology, as a discipline, is endoured with a vast range of analytical techniques that can be used to enhance the understanding of factors influencing the spread of disease among animal populations, the quality of data used to support these techniques is often lacking. The challenge in the years ahead, for both developed and developing countries, is to set in place the appropriate infrastructures to collect details of animal populations consistent in quality over time and space.

Orientador: João Frederico da Costa Azevedo Meyer / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica / Made available in DSpace on 2018-08-15T23:20:24Z (GMT). No. of bitstreams: 1 Souza_JulianaMartaRodriguesde_M.pdf: 3448446 bytes, checksum: c0a56c82b26926f022b1fbbb4b9e4fbe (MD5) Previous issue date: 2010 / Resumo: Esta dissertação de mestrado do grupo de biomatemática do Instituto de Matemática Aplicada e Computacional da UNICAMP, com auxílio de Bolsa de mestrado da CNPq, é resultado de dois anos, 2008 e 2009, de estudo a respeito da dispersão do risco de contágio do H5N1. Após tratar brevemente da estrutura viral; do papel das aves que sofrem sua ação; dos problemas financeiros que o H5N1 traria ao Brasil e já inflingiu em outras nações; o trabalho concentra-se em modelar e simular um ambiente formado de duas populações de comportamento distinto. A primeira, de aves silvestre, livres, que podem migrar. A segunda população consiste de aves restritas ao controle de um criador; não voam, não se espalham além dos limites da pequena localidade onde são criadas para fins de subsistência. Cada uma das três subdivisões destas populações, de acordo com o status em relação à doença, é modelada por uma equação diferencial parcial, compondo um sistema cuja solução numérica, necessária por conta das descontinuidades das condições iniciais, prediz o comportamentos da infecção em função do tempo e do espaço. Dentre os resultados alcançados, destaca-se: o homem parece ter chance de conter o espalhamento do vírus. Para isso teria de sacrificar todos os animais de pequenas criações e, então indivíduos da população silvestre, mas a uma taxa menor do que eles são capazes de se reproduzir, ou seriam levados a extinção. Também estão contidos neste trabalho, o estudo dos estados estacionários do sistema e a estimativa de que o coeficiente de difusão do H5N1 assumiria valores entre 0,025 e 0,5 km²/dia / Abstract: This dissertation from the IMECC, UNICAMP, Biomathematical Group, with funds offered by CNPq, is the result of two years, 2008 and 2009, of study about the spreading of H5N1 risk of infection. After treating briefly the viral structure; the birds that suffer the virus; the financial problems that the disease would bring to Brazil and has already inflicted to other nations; this paper concentrates in modeling and simulating an environment composed by two distinct behaviour population. The first one is free wild birds, that migrate. The second population consists of birds restricted to a farmer control; they don't fly, don't spread beyond little farms limits where they are raised to subsistence purposes. After dividing each of these two populations in order three, acording to their status in relation to the H5N1 infection, they are modeled by means of Partial Differential Equation, composing a non-linear system which requires numerical solution because of descontinuous inicial conditions and predicts the infection behaviour in spatial and temporal terms. Among the results figure: Humans, by completely sacrifing small farms birds and, then, wild birds in smaller rate than they reproduce themselves, seems to have a chance of prevent the virus to spread even further. This paper also study stationary states and determine, through computational methods, the H5N1 coefficient range, among 0.025 and 0.5 km²/day / Mestrado / Biomatematica / Mestre em Matemática Aplicada

Introducción: El transporte público en ciudades grandes como Lima puede favorecer el contagio de enfermedades transmitidas por aire, debido al hacinamiento, falta de ventilación y una permanencia prolongada en espacios reducidos. Materiales y métodos: Se realizó un estudio transversal en 592 universitarios de Lima para evaluar la relación entre el uso frecuente de transporte público y la presencia de síndrome gripal. Se definió síndrome gripal como el autorreporte de fiebre más dolor de garganta o tos en las últimas dos semanas, se evaluó el tipo de transporte más usado para acudir a la universidad. Se calculó los OR crudos y ajustados usando regresión logística simple y múltiple. Resultados: El 12,0% (71/592) presentó síndrome gripal en las últimas dos semanas. Se encontró asociación con el uso de transporte público (OR=3,6; IC95% 1,2- 10,2) y con tener contacto en la casa con alguien con síndrome gripal (OR=1,8; IC95% 1,1- 3,1) en el modelo de regresión logística múltiple. No se encontró asociación con la edad, vacunación frente a la influenza, vivir con niños, fumar cigarrillo y antecedentes patológicos. Conclusión: El uso de transporte público está asociado con la presencia de síndrome gripal en un grupo de estudiantes universitarios de Lima. / Background: Public transport in big cities like Lima may favor the spread of air-borne diseases due to overcrowding, poor ventilation and a prolonged stay in confined spaces. Material and methods: We performed a cross-sectional study in 592 students from a private university in Lima to evaluate the relationship between the frequent use of public transport and the presence of influenza-like illness (ILI). Self-report of ILI was defined as fever plus cough or sore throat in last two weeks, most used type of transport to go to university. OR crude and adjusted were calculated used simple and multiple logistic regression. Results: 12.0% (71/592) had ILI in the past two weeks. Use of public transport (OR = 3.6; 95% CI 1.2 to 10.2) and have contact with someone with ILI at home (OR = 1.8; 95% CI 1.1 to 3.1) were found associated in multiple logistic regression model. No association with age, vaccination against influenza, living with children, smoke and pathological history. In conclusion, the use of public transport is associated with the presence of ILI in a group of university students from Lima.