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No description available.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Chagas disease is one of the most important parasitic diseases in Latin America, transmitted by triatomine, has reached more than 10 million people. This illness is typical of rural environments and inadequate housing provides shelter to the vector the disease transmitter. The aim of this study was to investigate the presence of Trypanosoma cruzi in triatomines captured in intradomiciliary and surroundings in cities in the southeast region of CearÃin. This is a retrospective descriptive study, by consulting the archives of Control Program of Chagas Disease in Regional Laboratory of Endemic Diseases of Limoeiro do Norte â CE, which attends the cities that were studied from 2009 to 2011. During the study were captured a total of 18.408 specimens of insects, including nymphs and adults inside the home and outside homes. Of this total, 17.910 specimens were examined, representing 97,29%. The number of nymphs was taken about three times greater than the number of adults. The year of 2010 was the one with the highest number of captures, with a total of 8.548 triatomines, distributed among nymphs (6.115) and adults (2.433), and 637 inside of the houses and 7.911 around the houses. This year presented an infection rate of 1.30%, with 107 positive triatomines, being Quixerà the city with the highest infection rate in that year. The infection rate in adults triatomine (1.92%) was higher than in nymphs (1.21%). The species captured during the study period were Triatoma pseudomaculta, Triatoma brasiliensis, Panstrongylus megistus, Panstrongylus lutzi and Rhodnius nasutus. Of these species, T. pseudomaculta was the most captured throughout the study period, with 12.643 specimes. During this study, were 11 cities studied, and the most infested was Tabuleiro do Norte with 3.976 specimens, followed by Ãrere with 3.289. The city with the highest infection rate during the study period was Limoeiro do Norte (5,00%) with a total of 125 triatomines positive, followed by Quixerà (2.39%). At the end of the study, we can conclude that it is still necessary to intensify Control Program of Chagas disease, in order to avoid the maximum transmission of this disease. Finally we highlight the importance of conducting educational programs to the population in order to provide guidance to the public on disease prevention, such as towing houses, fix cracks and maintain clean environments at home and around the homes to prevent colonization of the approach and vectors. / A doenÃa de Chagas à uma das doenÃas parasitÃrias mais importante da AmÃrica Latina, transmitida por triatomÃneos jà atingiu mais de 10 milhÃes de pessoas. Essa enfermidade à tÃpica de ambientes rurais e habitaÃÃes inadequadas que oferecem abrigo ao vector transmissor da doenÃa. O presente estudo tem como objetivo investigar a presenÃa de Trypanosoma cruzi em triatomÃneos capturados nos intra e peridomicÃlios, em municÃpios da regiÃo sudestedo estado do CearÃ. Trata-se de um estudo retrospectivo descritivo, de consulta aos arquivos do Programa de Controle da DoenÃa de Chagas do LaboratÃrio Regional de Endemias do Limoeiro do Norte â CE, que atende os municÃpios que foram estudados no perÃodo de 2009 a 2011. Durante o estudo foi capturado um total de 18.408 exemplares de triatomÃneos, entre ninfas e adultos no intradomicÃlio e peridomicÃlio. Desse total, 17.910 exemplares foram examinados, representando 97,29 % dos capturados. O nÃmero de ninfas capturadas foi cerca de trÃs vezes maior que o nÃmero de adultos. O ano de 2010 foi o ano com maior nÃmero de capturas, com um total de 8.548 triatomÃneos capturados, distribuÃdos entre ninfas (6.115) e adultos (2.433), sendo 637 no intradomicÃlio e 7.911 no peridomicÃlio. O Ãndice de infecÃÃo nesse ano foi de 1,30%, com 107 triatomÃneos positivos, sendo Quixerà o municÃpio com maior Ãndice de infecÃÃo. O Ãndice de infecÃÃo em adultos (1,92%) foi maior do que em ninfas (1,21%). As espÃcies capturadas durante o perÃodo de estudo foram Triatoma pseudomaculta, Triatoma brasiliensis, Panstrongylus megistus, Panstrongylus lutzi e Rhodnius nasutus. Dessas espÃcies, T. pseudomaculta foi a mais capturada durante todo o perÃodo de estudo, com 12.643 exemplares. Durante o perÃodo de estudo foram estudados 11 municÃpios, sendo o mais infestado Tabuleiro do Norte com 3.976 exemplares, seguido de Ãrere com 3.289 exemplares. O municÃpio que apresentou maior Ãndice de infecÃÃo durante o perÃodo de estudo foi Limoeiro do Norte (5,00%) com um total de 125 triatomÃneos positivos, seguido de Quixerà (2,39%). Ao fim do estudo, pode-se concluir que ainda faz-se necessÃria a intensificaÃÃo do Programa de Controle da DoenÃa de Chagas, para poder evitar ao mÃximo a transmissÃo da doenÃa. Finalmente destaca-se a importÃncia de realizar programas educativos à populaÃÃo com a finalidade de dar orientaÃÃes à populaÃÃo na prevenÃÃo da doenÃa, tais como rebocar as casas, corrigir frestas e manter limpos os ambientes no peridomicÃlio e no domicÃlio para evitar a aproximaÃÃo e colonizaÃÃo dos vetores.

The main goal of this project is to investigate the behaviors of parameters used when modeling an epidemic. A stochastic SIHDRe model is used to simulate how an epidemic evolves over time. The SIHDRe model has nine parameters, and this project focuses on the infection rate (β) and the fraction of infections leading to deaths (FID), with all other parameters being considered known. Both parameters are time dependent. To estimate the two chosen parameters, this project uses synthetic data so that comparisons between estimations with true parameters are possible. A dynamic optimization procedure inspired by Model Predictive Control is utilized for the predictions. Using synthesized data from hospitalizations and deaths, a cost function is minimized to obtain estimations of the parameters. Only a subset of the time span, called a window, is considered for every parameter optimization. The parameters within the window are optimized and the window then moves forward in time defined by a time step until the parameters are optimized over the whole time span. To obtain error estimations of the parameters, synthetic bootstrapping is used, using optimized parameters to simulate new epidemics of which the parameters are optimized. The square difference between the new estimations compared to the original estimations can be used to obtain the standard deviation of the estimated parameters. This project also discusses how regularization parameters within the cost functions are chosen so that the estimated parameters will be most similar to the real parameter values, and end-of-data effects, i.e. increased uncertainty towards the end of a window, is also discussed. / Projektet undersöker hur olika parametrar till en epidemisk modell kan skattas. En stokastisk SIHDRe modell (Susceptible, Infected, Hospitalizalized, Dead, Recovered) används för att simulera hur en epidemi utvecklas över tid. SIDHRe modellen delar in populationen i olika grupper baserat på hur epidemin har påverkat dem, till exempel om de har blivit smittade eller om de har hamnat på sjukhus på grund av sjukdomen. Personer kan flyttas mellan olika grupper beroende på en rad parametrar samt storleken på de olika grupperna. Detta projekt fokuserar på att skatta två parameterar: β, som påverkar hur personer med risk för infektion blir smittade, samt FID som påverkar hur många infekterade som dör av sjukdomen. Modellen har nio parametrar totalt och alla andra parametrar anses kända. Projektet använder syntetisk data, som gör det möjligt att jämföra skattningar av parametrarna med deras sanna värden. Båda okända parametrarna är tidsberoende. För att bestämma parametervärdena används en dynamisk optimiseringsmetod. Data från antal individer inlagda på sjukhus samt antal döda anses känt och kan användas för att minimera en kostfunktion som har de okända parametrarna som inmatningsvärden genom att ändra dessa. Tidsspannet begränsas till en mindre del, det sägs att man ser ett fönster av hela tidsspannet. Fönstret startar vid den första tidspunkten och kostfunktionen minimiseras för inmatningsvärden inom fönstret. När detta är gjort flyttas fönstret ett kort tidsteg fram i tiden och optimiseringsprocessen återupprepas tills fönstret når slutet av hela tidsserien och alla parametervärden har uppskattats. Dessa skattade parametervärden kan sen jämföras med de sanna värdena. För att kunna uppskatta felet när parametervärdena bestäms används en metod kallad ”Synthetic Bootstrap”. Grundidén är att parameterna uppskattas en gång ochdenna uppskattning används sen som inmatningsvärde till epidemimodellen. Nya epidemier simuleras och baserat på dessa simuleringar, kan nya parametervärden estimeras. Dessa kommer att skilja i värde på grund av att modellen är stokastisk. De nya uppskattningarna jämförs sedan med de första uppskattningarna och en uppfattning om skillnaden mellan dessa kan sedan beskrivas som en standardavvikelse mellan de nya skattningarna och den första skattningen. Projektet diskuterar också val av olika regulariseringsparametrar för kostfunktionen. Dessa kontrollerar hur mycket de uppskattade värdena kan ändras från tidpunkt till tidpunkt genom att ett stort värde minskar möjliga ändringar och ett litet värde ökar dem. Ett fenomen som kallas ”end-of-data effects” diskuteras också och handlar om att osäkerheten växer i ett fönster ju längre in i fönstret man är.

No description available.

The present thesis examines questions related to the temporal origin of the Flavivirus genus and the ecology of tick-borne pathogens. In the first study, we date the origin and divergence time of the Flavivirus genus. It has been argued that the first flaviviruses originated after the last glacial maximum. This has been contradicted by recent analyses estimating that the tick-borne flaviviruses emerged at least before 16,000 years ago. It has also been argued that the Powassan virus was introduced into North America at the time between the opening and splitting of the Beringian land bridge. Supported by tip date and biogeographical calibration, our results suggest that this genus originated circa 120,000 (156,100–322,700) years ago if the Tamana bat virus is included in the genus, or circa 85,000 (63,700–109,600) years ago excluding the Tamana bat virus. In the second study we estimate the prevalence of tick-borne encephalitis virus (TBEV) in host-seeking Ixodes ricinus from 29 localities in Sweden and compare our data with those of neighbouring countries. Nymphs and adult ticks were screened for TBEV using a real-time PCR assay. The mean TBEV prevalence for all tick stages combined was 0.26% for Sweden and 0.28% for all Scandinavian countries, excluding Iceland. The low prevalence of TBEV in nature may partly be explained by the fact that TBEV occurs in spatially small foci and that the inclusion of ticks from non-infected foci will reduce the prevalence estimate. In the third and fourth study, we conducted the first large-scale investigations to estimate the prevalence and geographical distribution of Anaplasma spp. and Rickettsia spp. in host-seeking larvae, nymphs and adults of I. ricinus ticks in Sweden. Ticks were collected from several localities in central and southern Sweden and were subsequently screened for the presence of Anaplasma spp. and Rickettsia spp. using a real-time PCR assay. For all active tick stages combined, the mean prevalence of Anaplasma spp. and Rickettsia spp. in I. ricinus in Sweden was estimated to 1.1% and 4.8%, respectively. It was also shown that A. phagocytophilum and R. helvetica are the main Anaplasma and Rickettsia species occurring in Sweden.

Made available in DSpace on 2014-12-17T14:10:17Z (GMT). No. of bitstreams: 1 CimariaPROS.pdf: 1137578 bytes, checksum: 6105cd049ff9ace294e10673c0d93fea (MD5) Previous issue date: 2008-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The shrimp farming industry is the most profitable area of the aquaculture at Rio Grande do Norte (RN) state, which is one of the largest producers in Brazil. However the infections that affect the shrimp cause major economic losses. The infection is a result of the interaction between the shrimp, the environment and pathogen. The change of these factors may lead to a condition of stress and susceptibility to opportunistic infections. One of these infections caused by Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is widely distributed in several countries and affects a wide range of hosts. To optimize conditions for production of Litopenaeus vannamei shrimp, the more species cultivated in Brazil, it is necessary to understand the effects of environmental factors in the susceptibility of this species to infections. The aim of this study was to determine the IHHNV prevalence and to investigate the influence of environmental factors as salinity, temperature, stocking density, dissolved oxygen and rainfall in the IHHNV incidence in L. vannamei grown in farms, in the RN state. To determine the IHHNV prevalence were used 1089 samples of L. vannamei collected in seven farms. To perform the study about the influence of environmental factors, 525 samples of L. vannamei shrimp were collected in eight farms located in regions of low (0-1 ), medium (21-30 ) and high (38-57 ) salinity, using extensive (&#8804;15 shrimp/m2 ), semi-intensive (18-33 shrimp/m2) or intensive (>36 shrimp/m2) stocking density systems. The IHHNV infection was determined in pleopod and hemolymph using the polymerase chain reaction (PCR). The environmental factors were recorded during the collection of animals, using a refractometer to measure the salinity and a multi-parameter meter to measure the temperature and concentration of dissolved oxygen in the water. The IHHNV prevalence in RN was 43% (468 infected shrimp out of 1089), varying on different farms. On the seven farms studied, IHHNV prevalence ranged from 18.6% to 54.8%. The infection rates in the shrimp cultured in low, medium and high salinity were respectively 43.10% (125/290), 31.2% (15/48) and 24.6% (46/187) and was significantly higher in shrimp grown in low salinity (P<0.001). The infection rates in ponds of extensive, semi-intensive and intensive systems were respectively, 28.7%, 28.28% and 47.84%, and was significantly higher in high stocking densities (P<0.001). This study indicated a high IHHNV prevalence and a significant effect of salinity and stocking density, but not of the temperature, rainfall and dissolved oxygen on the IHHNV infection rate in the L. vannamei shrimp cultured in the northeastern Brazil / A carcinicultura ? a ?rea da aquicultura mais rent?vel do Rio Grande do Norte (RN), que ? um dos maiores produtores do Brasil. Por?m, as infec??es que acometem os camar?es v?m causando importantes perdas econ?micas. A infec??o ? resultado da intera??o entre o camar?o, o meio ambiente e o pat?geno. A altera??o desses fatores, pode levar a uma situa??o de estresse e suscetibilidade ? infec??es oportunistas. Uma dessas infec??es, causada pelo v?rus da Infec??o Hipodermal e Necrose Hematopoi?tica (IHHNV), encontra-se largamente distribu?da em v?rios pa?ses e apresenta uma grande variedade de hospedeiros. Para otimizar as condi??es de produ??o do camar?o de cultivo Litopenaeus vannamei, a esp?cie mais cultivada no Brasil, ? necess?rio compreender os efeitos dos fatores ambientais na suscetibilidade dessa esp?cie ?s infec??es. O presente estudo teve por objetivo determinar a preval?ncia do IHHNV e investigar a influ?ncia de fatores ambientais como a salinidade, temperatura, densidade de estocagem, oxig?nio dissolvido e pluviosidade na incid?ncia do IHHNV em fazendas de cultivo do L. vannamei, no estado do RN. Para determinar a preval?ncia do IHHNV foram utilizados 1089 amostras de L. vannamei coletados de sete fazendas. Para a realiza??o do estudo sobre a influ?ncia de fatores ambientais 525 amostras do camar?o L. vannamei foram coletadas em oito fazendas localizadas em regi?es de ?guas oligohalinas (0-1 ), mesohalinas (21-30 ) e hipersalinas (38-57 ), utilizando sistema de densidade de estocagem extensivo (&#8804;15 camar?es/m2), semi-intensivo (18-27 camar?es/m2) e intensivo (>30 camar?es/m2). A infec??o pelo IHHNV foi determinada em ple?podos e hemolinfa utilizando a rea??o da polimerase em cadeia (PCR). Os fatores ambientais foram registrados durante a coleta dos animais nos viveiros das fazendas, utilizando um refrat?metro para medir a salinidade e um medidor multi-par?metro para medir a temperatura e o oxig?nio dissolvido da ?gua. A preval?ncia do IHHNV no RN foi 43% (468 camar?es infectados de 1089), variando nas diferentes fazendas. Nas sete fazendas estudadas, a preval?ncia do IHHNV variou de 18,6% a 54,8%. As taxas de infec??o nas fazendas de ?guas oligohalinas, mesohalinas e hipersalinas foram respectivamente 43,10% (125/290), 31,2% (15/48) e 24,6% (46/187) e foi significativamente maior em camar?es cultivados em ?guas oligohalinas (P<0,001). As taxas de infec??o nos viveiros de sistema extensivo, semi-intensivo e intensivo foram respectivamente, 28,7%, 28,28% e 47,84% e foi significativamente maior em alta densidade de estocagem (P<0,001). Neste trabalho foi encontrado uma alta preval?ncia do IHHNV e um efeito significativo da salinidade e da densidade de estocagem, mas n?o da temperatura, pluviosidade e concentra??o do oxig?nio dissolvido sobre a taxa de infec??o pelo IHHNV no camar?o L. vannamei cultivado no Nordeste brasileiro