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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Apports de la paléogénétique à l'étude des helminthes gastro-intestinaux anciens / Paleogenetics to study ancient gastrointestinal helminths

Côté, Nathalie 16 December 2015 (has links)
La paléoparasitologie est l’étude des restes de parasites préservés dans des échantillons archéologiques et permet de mieux comprendre l’état de santé des populations anciennes et d’obtenir des informations d’ordre anthropologique ou ethnologique, sur les régimes alimentaires ou les conditions d’hygiène au quotidien. Les restes de parasites peuvent être retrouvés sous forme de macro-restes (vers ou larves), d’antigènes, d’ADN ou d’œufs. Cesderniers peuvent être particulièrement bien préservés au cours du temps car ils sont composés en partie de chitine, les rendant résistants aux processus de dégradation. L’observation microscopique de leurs caractéristiques morphologiques et micrométriques permet d’identifier les taxons au niveau du genre ou de la famille. Dans le cadre de cette thèse, plusieurs helminthes gastro-intestinaux, dont les œufs sont fréquemment retrouvés dans des échantillons archéologiques, ont été ciblés par une approche génétique. Il s’agit des vers plats Tæniasaginata, T. solium, T. asiatica, Echinococcus granulosus, E. multilocularis, Diphyllobothriumlatum, D. dendriticum et D. nihonkaiense, des nématodes Trichuris trichiura, Enterobiusvermicularis et Ascaris sp. et des douves Fasciola hepatica, F. gigantica, Dicrocoeliumdendriticum et D. chinensis.La méthode « aMPlex Torrent » permet de détecter, dans un grand nombre d’échantillons archéologiques, une faible quantité d’ADN de parasites. Cette approche combine la spécificité et la sensibilité de la PCR au haut-débit du séquençage de nouvelle génération. Plusieurs vestiges, provenant de périodes et de régions géographiques diverses, ont été analysés. Des résultats génétiques ont été obtenus pour des échantillons aussi anciens que 7200 BP. Nous avons par ailleurs obtenus les premières séquences anciennes de Taenia sp., Diphyllobothriumsp., Echinococcus sp., et les premières séquences européennes d’Enterobius vermicularis. Auvu de ces résultats, notre approche apparait comme étant complémentaire à la microscopie. / Palaeoparasitogy, the study of parasite remains from archaeological samples, is adiscipline that can highlight questions about the health status of the ancient populations. It can give important anthropological or ethnological information such as the diet and the hygiene conditions of past societies. The remains can be preserved as macroremains (worms or larvae),antigens, DNA or eggs. Because they are partially made of chitin, eggs of gastrointestinalhelminths resist well over time to the taphonomic degradation process. It is possible to distinguish between different families or genera of parasites by looking at the morphological features of eggs. However, since several taxa share common features, the determination is rarelypossible at the species level. For this thesis, several parasite species for which eggs arecommonly observed in archeological samples have been studied by a genetic approach. Westudied the tapeworms Tænia saginata, T. solium, T. asiatica, Echinococcus granulosus, E.multilocularis, Diphyllobothrium latum, D. dendriticum, and D. nihonkaiense; the nematodesTrichuris trichiura, Enterobius vermicularis, and Ascaris sp.; and the flukes Fasciola hepatica,F. gigantica, Dicrocoelium dendriticum, and D. chinensis.The “aMPlex Torrent” approach has been set up to detect minute amounts of DNA from parasites in multiple archaeological samples. This approach combines the specificity andsensitivity of PCR to the throughput of Next-Generation sequencing. Several samples have been analyzed by this approach. We obtained genetic results for samples as old as 7200 BP and from various geographical and archeological contexts. We obtained the first ancient DNA sequences for Taenia sp., Diphyllobothrium sp., Echinococcus sp. and the first European sequences forEnterobius vermicularis. Genetic analyses and microscopic observations appear to be complementary. Indeed, at least one taxon per sample was detected by one of the two approaches.
142

Aplicação da metodologia de análise de perigo e pontos críticos de controle na disposição de efluentes tratados em solos tropicais e seu potencial uso agrícola / Application of risk analysis methodology and critical control points at the disposal of treated effluent in tropical soils and their potential agricultural use.

Jeferson Gaspar dos Santos 07 June 2016 (has links)
Introdução - A prática de reúso pela aplicação de esgotos tratados na agricultura atualmente é considerada parte integrante dos recursos hídricos por muitas nações. No entanto, oferece riscos à saúde da população pela presença de bactérias, cistos de protozoários, ovos de helmintos e vírus, capazes de sobreviver por longos períodos em ambientes desfavoráveis e apresentarem um curto tempo entre a infecção e o desenvolvimento da doença. Objetivo - Estabelecer medidas preventivas para o lançamento de efluentes nos ecossistemas aquáticos, controle sanitário na redução de patógenos transmitidos por águas contaminadas e a disposição de efluentes tratados em solos tropicais como ferramentas de auxílio do manejo integrado dos recursos hídricos em bacias hidrográficas, por meio do uso de metodologia de gerenciamento de risco com aplicação do Sistema APPCC, em um conjunto de tecnologias na produção de efluente tratado de esgoto de origem doméstica para avaliar o potencial de emprego em solos agrícolas. Métodos - A pesquisa foi desenvolvida na estação de tratamento de esgoto e no campo experimental para pesquisas de utilização de efluente na agricultura no município de Lins. Os indicadores biológicos estudados e os pontos de amostragem foram determinados através da utilização da metodologia de controle de qualidade Análise de Perigos e Pontos Críticos de Controle (APPCC). Foram coletadas amostras do solo irrigado e dos poços de monitoramento do lençol freático. As amostras foram submetidas a análises físico-químicas, microbiológicas e parasitológicas. Aos resultados obtidos foi aplicada a Avaliação Quantitativa do Risco Microbiológico, para a determinação do risco anual de infecção. Resultados - O efluente final apresentou concentrações médias de 8,13x105 NMP/100 mL de coliformes totais e 4,69x105 NMP/100 mL de Escherichia coli, não sendo observados ovos de helmintos. O solo apresentou maior concentração de coliformes totais e E. coli na camada superficial 1,01x106 e 8,70x103, diminuindo ao longo da profundidade. Os ovos de helmintos foram encontrados entre a superfície e os 15 cm de profundidade em concentrações entre 0,07 e 0,87 ovos/g de peso seco. Foi constatada a presença de adenovírus em concentração de 3,56x105 cópias genômicas/g entre os 5 e 10 cm de profundidade em 2015. Nos poços de monitoramento foram constatadas concentrações de coliformes totais variando entre < 1,00 e 1,01x103 NMP/100 mL e E. coli entre <1,00 e 1,00x100 NMP/100 mL. Não foi observada a presença de vírus entéricos. O risco anual de infecção estimado para E. coli no efluente final foi 1,02x10-2 pppa, no solo variou entre 2,68x10-3 e 7,59x10-3 pppa e nos poços de monitoramento variou entre 1,42x10-8e 4,38x10-9 pppa. Para os ovos de helmintos observados no efluente do tratamento primário o risco anual de infecção calculado foi 4,04x10-2 pppa e no solo variou entre 9,57x10-1 e 9,76x10-1 pppa. Conclusões No período da pesquisa, as amostras dos sistemas de tratamento de esgoto e de irrigação demonstraram atender as expectativas de remoção de patógenos condizentes aos seus parâmetros de projeto, havendo restrições para seu lançamento em corpos hídricos e aplicação na agricultura. O solo mostrou capacidade de retenção dos organismos patogênicos nos primeiros 60 cm de profundidade, reduzindo as suas concentrações a níveis inferiores a 1,00 NMP/100 mL nos aquíferos. / Introduction - Currently, the practice of reuse through the application of treated sewage in agriculture considers an integral part of water resources for many nations. However, threatens the health of the population by the presence of bacteria, protozoan cysts, helminth eggs and viruses able to survive for long periods in harsh environments and present a short time between infection and development of disease. Objective - Establish preventive measures for the release of effluents on aquatic ecosystems, sanitary control in the reduction of pathogens transmitted by contaminated water and the disposal of treated effluent in tropical soils as aid tools in integrated management of water resources in river basins. For this purpose it was employed as risk management methodology the Hazard Analysis and Critical Control Points system (HACCP) in a set of technologies in the treated effluent production of domestic sewage to assess the employment potential in agricultural soils. Methods - The study was conducted in the sewage treatment plant and in an adjoining experimental field situated at Lins city. The biological indicators and the sampling points were determined by using the quality control methodology Hazard Analysis and Critical Control Points (HACCP). Samples of irrigated soil and groundwater monitoring wells were collected. The samples were subjected to analysis, physical-chemical, microbiological and parasitological. The results obtained was applied to Quantitative Microbial Risk Assessment (QRMA), for determining the annual risk of infection. Results - The final effluent presented average concentrations of 8.13x105 MPN / 100 mL of total coliforms and 4.69x105 MPN / 100 mL of Escherichia coli, not being observed helminth eggs. The soil showed the highest concentration of total coliforms and E. coli in the surface layer and 1.01x106 8.70x103, decreasing along the depth. Eggs from helminths were found between the surface and 15 cm depth in concentrations from 0.07 to 0.87 eggs / g dry weight. It was found the presence of adenovirus in concentration 3.56x105 genomic copies / g between 5 and 10 cm depth in 2015. In monitoring wells total coliform concentrations were found ranging from <1.00 and 1.01x103 NMP / 100 mL and E. coli between <1.00 and 1.00x100 MPN / 100 mL. It was not observed the presence of enteric viruses. The estimated annual risk of infection to E. coli in the final effluent was 1.02x10-2 pppy, soil ranged from 2.68x10-3 and 7.59x10-3 pppy and monitoring wells ranged from 1.42x10-8 e 4.38x10-9 pppy. For helminth eggs observed in the effluent from the primary treatment, the annual risk of infection was calculated 4.04x10-2 pppy and soil ranged from 9.57x10-1 and 9.76x10-1 pppy. Conclusions - During the survey period, samples of sewage and irrigation treatment systems showed meet the expectation removal of pathogens consistent to its design parameters, with restrictions on its release in water and applied in agriculture bodies. The soil of pathogenic organisms showed retention capacity in the first 60 cm depth by reducing its concentration to levels below 1.00 MPN / 100 mL in aquifers.
143

Helminth parasites of sheep and goats in Eastern Ethiopia : epidemiology, and anthelmintic resistance and its management /

Menkir Mekonnen, Sissay, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.
144

Avaliação do potencial anti-helmíntico do extrato etanólico e óleo essencial de Chenopodium ambrosioides L. no controle de Ancylostoma spp. de cães

Monteiro, Jessica Nascimento Moraes 10 December 2012 (has links)
Made available in DSpace on 2016-12-23T13:53:37Z (GMT). No. of bitstreams: 1 Jessica Nascimento Moraes Monteiro.pdf: 621105 bytes, checksum: 18de4ef14328874b3985d6471aa06448 (MD5) Previous issue date: 2012-12-10 / Phytotherapy is often used for parasitic diseases controlling in several animal species. This study aimed to evaluate the infective larvae (L3) of Ancylostoma spp. immersed in ethanol extract and Chenopodium ambrosioides L. essential oil in the in vitro test. It was used distilled water (negative control) and albendazole and commercial association of praziquantel, pyrantel pamoate and febantel (positive controls). The ethanol extract of C. ambrosioides L. at concentration of 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 8.0%, 10.0%, 12.0 % and 20% had insufficient activity to the larvicidal effect. The essential oil at concentration of 150μL.mL-1 was effective against L3. The formulation of a biscuit manipulated with a concentration of 37,5 μL.g-1 of the C. ambrosioides L essential oil reduced the number of eggs per gram of the dogs feces. Twenty-six adult dogs were divided into three groups for in vivo testing: F1 (biscuit without active ingredient), F2 (biscuit with C. ambrosioides L. active principle), F3 (biscuit with allopathic active ingredient). At the CBC, there were significant differences in F1 for values of red blood cells, hematocrit and mean corpuscular hemoglobin concentration (MCHC) and albumin in serum biochemistry. The F2 showed difference in MCHC and in biochemical the serum protein and globulin. The F3, lymphocytes and monocytes values in the blood count and albumin and globulin were different between M1 and M2. At the parasitological exam F1 remained parasitized, while the F2 reduced significantly the infection and F3 showed negative result in M2. It is concluded that the formulation of a biscuit manipulated with C. ambrosioides L essential oil reduced the Ancylostoma spp. infection in naturally infected dogs / A fitoterapia é frequentemente utilizada no controle das parasitoses de diversas espécies animais. Objetivou-se avaliar as larvas infectantes (L3) de Ancylostoma spp. imersas em extrato etanólico e óleo essencial de Chenopodium ambrosioides L. no teste in vitro. Utilizou-se água destilada (controle negativo) e albendazole e associação comercial de praziquantel, pamoato de pirantel e febantel (controles positivos). O extrato etanólico de C. ambrosioides L. nas concentrações 0,5%, 1,0%, 2,0%, 3,0%, 4,0%, 5,0%, 6,0%, 8,0%, 10,0%, 12,0% e 20% apresentaram insuficiente atividade para o efeito larvicida. O óleo essencial na concentração de 150μL.mL-1 foi eficaz contra L3. A formulação de biscoito manipulado com a concentração de 37,5μL.g-1 do óleo essencial C. ambrosioides L reduziu o número de ovos por grama de fezes dos cães. Vinte e seis cães adultos foram dividos em três grupos para o teste in vivo: F1 (biscoito sem princípio ativo), F2 (biscoito com princípio ativo de C. ambrosioides L.), F3 (biscoito com princípio ativo alopático). No hemograma, houve diferença significativa no F1 para os valores de hemácias, hematócrito e concentração de hemoglobina corpuscular média (CHCM) e albumina na bioquímica sérica. O F2 apresentou diferença no CHCM e na bioquímica a proteína sérica e globulina. O F3, os valores para linfócitos e monócitos no hemograma e a albumina e globulina foram diferentes entre o M1 e M2. No exame parasitológico o F1 manteve-se parasitado, enquanto o F2 reduziu de forma significativa a infecção e o F3 apresentou resultado negativo no M2. Conclui-se que a formulação de biscoito manipulado com óleo essencial C. ambrosioides L reduziu a infecção de Ancylostoma spp. em cães naturalmente parasitados
145

Biodiversidade dos parasitas de peixes provenientes do rio Sapucaí-Mirim, Estado de São Paulo, Brasil

Zago, Aline Cristina. January 2016 (has links)
Orientador: Reinaldo José da Silva / Resumo: Nos últimos anos, os parasitas foram reconhecidos como importantes componentes dabiodiversidade global, dado os importantes papéis desempenhados por esses organismosem ecossistemas naturais. Embora o conhecimento sobre a diversidade de parasitas tenhaaumentado nas últimas décadas, o número de espécies de parasitas de peixes no Brasil érelativamente baixo quando comparado com a biodiversidade das espécies hospedeiras.Desta forma, o presente trabalho teve como objetivo realizar um levantamento dabiodiversidade dos parasitas de peixes procedentes de quatro locais em uma área sob ainfluência de Pequenas Centrais Hidrelétricas (PCHs) no rio Sapucaí-Mirim, Estado de SãoPaulo, Brasil, bem como avaliar a estrutura das comunidades de metazoários parasitas depeixes Characiformes e de quatro espécies do gênero Leporinus. Durante o período demarço de 2012 a julho de 2013, foram coletados 462 espécimes pertencentes a 16 espéciesde peixes das ordens Characiformes, Siluriformes, Gymnotiformes e Perciformes.Observou-se que 86,58% dos espécimes estavam parasitados por pelo menos um taxon demetazoário parasita. Os parasitas encontrados pertenciam a oito diferentes grupos(Myxozoa, Monogenea, Digenea, Cestoda, Nematoda, Acantocephala, Arthopoda eAnnelida), sendo coletado um total de 6.830 parasitas. Noventa e sete taxa de parasitasforam encontrados, sendo que a classe Monogenea foi o grupo que apresentou o maiornúmero de espécies, seguido do filo Nematoda e da s... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Recently, parasites have been recognized as important components of global biodiversitybecause the important roles played by these organisms in natural ecosystems. Althoughknowledge about the diversity of parasites has increased in recent decades, the number ofparasite species of fishes in Brazil is relatively low compared to the biodiversity of hostspecies. Thus, this study aimed to survey the biodiversity of fish parasites from foursampling sites in an area under the influence of Small Hydroelectric Power Plants in theSapucaí-Mirim River, São Paulo State, Brazil, as well as to evaluate the structure ofmetazoan parasite communities of Characiformes and four species of Leporinus sp. FromMarch 2012 to July 2013, 462 fish specimens of 16 species of Characiformes,Siluriformes, Perciformes, and Gymnotiformes were collected. It was observed that86.58% of fish specimens were parasitized by at least one metazoan parasite taxon. Theparasites found belonged to eight different groups (Myxozoa, Monogenea, Digenea,Cestoda, Nematoda, Acantocephala, Arthopoda and Annelida) and a total of 6,830parasites were collected and analyzed. Ninety-seven parasite taxa were found, andMonogenea was the group that had the highest number of species, followed by Nematodaand Digenea. The parasite communities of Characiformes showed mainly differencesamong the host species, although belonging to the same order or family. The sampling site,condition factor and the host body ... (Complete abstract click electronic access below) / Doutor
146

Par?metros parasitol?gicos e desempenho produtivo de ovinos naturalmente infectados com nematoides gastrintestinais mantidos em diferentes pastagens tropicais / Parasitological parameters and productive performance of sheep naturally infected with gastrointestinal nematodes in different tropical pastures

Andrade Junior, Alberto Luiz Freire de 10 April 2013 (has links)
Made available in DSpace on 2014-12-17T15:34:47Z (GMT). No. of bitstreams: 1 AlbertoLFAJ_DISSERT.pdf: 1671046 bytes, checksum: 8699a01f6b8beb7c7731350f466df41d (MD5) Previous issue date: 2013-04-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The control of gastrointestinal nematodes of small ruminants is usually done with anthelmintics. However, due to the emergence of ever-increasing parasite resistance to these drugs, looking up an alternative control parasites. One of this is sought in pasture management, as these are the sources of animals` infection by L3 infective larvae of helminths. The aim of this study was to evaluate the performance of sheep to natural infections by gastrointestinal nematodes grazing Panicum maximum cv. Massai and cv. Aruana, and Brachiaria brizantha cv. Piat? and cv. Marandu. The work was conducted from May to August-2011 with 48 male sheeps SRD versus Santa In?s breed. The animals were naturally infected with gastrointestinal nematodes, and maintained in four different cultivars of tropical forage grasses, naturally contaminated with eggs and larvae of gastrointestinal nematodes. Each week the animals were phenotypically characterized by parasitological examinations (eggs per gram of feces - EPG, and feces culture), hematological (packed cell volume PCV, and blood eosinophil count) method to evaluate the Famacha? colorof ocular mucosa, and the measures of body condition score and weight. In pastures was made the recovery of infective larvae in order to determine the quantity of L3 present in the pasture. The experimental design was a randomized completed block with two replications and before the entry of animals in the paddocks, they have been wormed. The experiment was ended when the animals reached 32.0 kg liveweight, and then were slaughtered and autopsies performed for the recovery and identify parasites of the abomasum, small intestine and large intestine. Results were subjected to analysis of variance, t test and Tukey`s test. The animals kept on pastures of Marandu grass had lower EPG counts, higher percentage of packed cell volume and higher average weight; those who remained in the Piat? pasture had lower eosinophil counts per microliter of blood. About the Famacha?, the highest prevalence was Famacha 2, and the body condition score ranged between 2 and 3. The results of feces cultures and recovery of larvae on pastures showed the presence of larvae of Trichostrongylus sp., and at the necropsy too. This way, it was concluded that the grass cultivars influences the sheep parasite load; the Famacha, together with EPG and packed cell volume are important indicators for use in controlling gastrointestinal nematode infections. The Trichostrongylus sp. was the most prevalent parasite in sheep during the rainy season / O controle dos nematoides gastrintestinais de pequenos ruminantes usualmente ? feito pela administra??o de anti-helm?nticos. Por?m, devido ao aparecimento cada vez mais crescente da resist?ncia parasit?ria a estas drogas, busca-se um controle alternativo e eficaz para as parasitoses. Uma das alternativas est? no manejo das pastagens, j? que estas s?o as fontes de infec??o dos animais pelas larvas infectantes L3 dos helmintos. Assim, o objetivo deste trabalho foi avaliar o desempenho de ovinos frente ?s infec??es naturais por nematoides gastrintestinais mantidos em pastagens de Panicum maximum cv. Massai e cv. Aruana, e Brachiaria brizantha cv. Piat? e cv. Marandu. O experimento foi realizado de Maio a Agosto/2011, com 48 ovinos machos, mesti?os SRD x Santa In?s, naturalmente infectados por nematoides gastrintestinais e mantidos em quatro diferentes cultivares de gram?neas forrageiras tropicais naturalmente contaminadas por ovos e larvas de nematoides gastrintestinais. Semanalmente, os animais foram caracterizados fenotipicamente atrav?s de exames parasitol?gicos (ovos por grama de fezes OPG e coprocultura), exames hematol?gicos (volume globular VG, e contagem de eosin?filos sangu?neos), pelo m?todo Famacha? para avaliar a colora??o da mucosa ocular, e pelas medidas de escore de condi??o corporal e ganho de peso. Nas pastagens foi feita a recupera??o das larvas infectantes, a fim de determinar a quantidade de L3 presentes no pasto. O delineamento experimental usado foi o de blocos casualizados com duas repeti??es, e antes da entrada dos animais nos piquetes, os mesmos foram vermifugados. O per?odo experimental foi finalizado quando os animais atingiram 32,0 kg de peso vivo, e em seguida foram abatidos e realizada a necr?psia para recupera??o e identifica??o dos parasitos do abomaso, intestino delgado e intestino grosso. Os resultados obtidos foram submetidos a an?lise de vari?ncia, teste t e teste de Tukey. Os animais mantidos nas pastagens de capim Marandu apresentaram menores contagens de OPG, maior porcentagem de volume globular e maior m?dia de peso; os que permaneceram na pastagem Piat? apresentaram menores contagens de eosin?filos por microlitro de sangue. O Famacha de maior preval?ncia foi o Famacha 2 e o escore de condi??o corporal oscilou entre os ?ndices 2 e 3. Os resultados das coproculturas e a recupera??o das larvas nas pastagens evidenciou presen?a de larvas de Trichostrongylus sp., bem como na necropsia este tamb?m foi o parasito de maior preval?ncia. Portanto, pode-se concluir que a cultivar forrageira influencia na carga parasit?ria dos ovinos; o Famacha, juntamente com o OPG e VG constituem indicadores importantes para serem utilizados no controle das verminoses gastrintestinais; o Trichostrongylus sp. foi o parasito de maior preval?ncia nos ovinos no per?odo chuvoso
147

Aspectos epidemiológicos da esquistossomose e co-infecção por enteroparasitas utilizando geoprocessamento / EPIDEMIOLOGICAL ASPECTS OF SCHISTOSOMIASIS AND COINFECTION PARASITES USING GEOPROCESSING.

Rollemberg, Carla Virginia Vieira 16 March 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work aims to investigate the relationship between infection with Schistosoma mansoni and other intestinal parasites. We performed two study designs: the first (Article 1) was an ecological study to evaluate the frequency and geographic distribution of diagnosed cases of infection with S. mansoni and intestinal parasites using a database survey of Health Department of the Sergipe State from 2005 to 2008. We created the database from the raw data of the Schistosomiasis Control Program of Sergipe (PCE-SE) in which we performed analysis of frequency and geographical distribution of infections caused by S. mansoni and other parasitic diseases with the software SPRING 5.0 to create maps. The results of this study revealed high incidence of schistosomiasis in many municipalities. Analyzing data from the IBGE (Brazilian Institute of Geography and Statistics) and the Superintendence of Water Resources (SRH) of these municipalities, it was observed that the municipalities with higher prevalence of schistosomiasis (> 15%) have lower sewerage coverage (Sanitation Index) as compared with those with a lower prevalence (< 15%) (p = 0.0513). We also observed higher education index (IDHE) in municipalities with prevalence of hookworm lower than 10% as compared to the ones with prevalence over 10% (p = 0.0365). The second model was a cross-sectional study in the city of Ilha das Flores, Sergipe, Brazil (Article 2), aiming to study in an area with high prevalence of schistosomiasis the interaction of several socio-environmental variables, epidemiological and clinical data with a geographical perspective. In this study, 570 individuals were studied using a questionnaire to collect data on socioeconomic, clinical, epidemiological and coproparasitological conducted from September 2008 to April 2010. This study has created a georeferenced database and geostatistical analysis conducted to determine and predict poliparasitism between S. mansoni and intestinalparasites, using the Kernel density estimator. The results showed that Trichuris trichiura (54.8%), Ascaris lumbricoides (49.2%), Entamoeba coli (25.6%) and S. mansoni (24.0%) were the predominant species. Spatial statistics has enriched the traditional measures of statistical estimation of the dispersion of epidemiologic risk factors determining the likely sites of contamination. We observed associations between S. mansoni infection and male gender (65.2% males, p = 0.003), being a farmer (p <0.001) or a fisherman (p <0.001), low educational level (p<0.001) and low income (p = 0.0005), any level of natural water contact (p <0.001) and drinking untreated water (p <0.001). We detected associations between A. lumbricoides (p=0,0002) and hookworm (p=0,01) infections with low income and between A. lumbricoides and T. trichiura with drinking untreated water (p=0.02 for both) and with open sewerage (p=0.001 and, p=0.0005, respectively). The data call for an integrated approach to effectively control multiple parasitic infections from the perspective of public health. / O presente estudo visa investigar a relação entre a infecção por Schistosoma mansoni e outras enteroparasitoses. A pesquisa foi delineada em dois modelos de estudo: no primeiro (Artigo 1) foi realizado um estudo ecológico objetivando avaliar a frequência e distribuição geográfica dos casos diagnosticados de Infecção por S. mansoni e enteroparasitas utilizando um levantamento da base de dados da Secretaria de Saúde do Estado de Sergipe de 2005 a 2008. A partir da matriz bruta do Programa de Controle da Esquistossomose de Sergipe (PCE-SE) formulou-se banco de dados no qual se realizou análises de freqüência e distribuição geográfica das infecções por S. mansoni e outros enteroparasitas com o software SPRING 5.0 para confeccção de mapas. Os resultados deste estudo revelaram elevada frequência de esquistossomose em diversos municípios do Estado. Analisando os dados do IBGE (Instituto Brasileiro de Geografia e Estatística) e da Superintendência de Recursos Hídricos (SRH) destes municípios, foi observado que os municípios com uma prevalência da esquistossomose menor que 15% há maior rede de esgoto (Indice de Higiene) em comparação com aqueles com prevalências maiores do que 15% (p=0,05). Foi também encontrado maiores IDH educacionais nos municípios com prevalência de ancilostomídeos menores de 10% em comparação com os maiores de 10% (p=0,04). O segundo modelo foi um estudo transversal no município de Ilha das Flores-SE (Artigo 2), objetivando estudar em uma área com elevada prevalência de esquistossomose a interação de diversas variáveis socioambientais, epidemiológicas e clínicas com uma perspectiva geográfica. Neste estudo, foram estudados 570 indivíduos através de inquérito com coleta de dados socioeconômicos, clínico-epidemiológicos e coproscópicos georeferenciados, realizado de Setembro 2008 a abril de 2010. Neste estudo foi criado um banco de dados georeferenciado e realizado análise geoestatística para determinar e predizer 11 poliparasitismo entre S. mansoni e parasitas intestinais, através do estimador de densidade Kernel. Os resultados demonstram que Trichuris trichiura (54,8%), Ascaris lumbricoides (49,2%), Entamoeba coli (25,6%) e S. mansoni (24,0%), foram as espécies predominantes. A estatística espacial analisou a estimativa da dispersão de fatores de risco epidemiológicos para determinar os locais prováveis de contaminação. Foram encontradas associações entre infecção por S. mansoni e ser do gênero masculino (65.2% homens, p = 0,003), ser lavrador (p <0,001) ou pescador (p <0,001), ter baixo nível educacional (p<0,001) e ter baixa renda (p = 0,0005), ter qualquer nível de contato com águas naturais (p <0.001) e beber água não tratada (p <0,001). Detectamos associações entre A. lumbricoides (p=0,0002) e Ancylostoma/ Necator (p=0,01) com baixa renda e entre A. lumbricoides e T. trichiura com beber água não tratada (p=0,02 for ambos) e ter esgoto a céu aberto (p=0,001 e p=0,0005, respectivamente). Estes dados podem ser integrados ao programas de controle de esquistossomose e outras parasitoses.
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Communautés de parasites, immunité et succès d'invasion des rongeurs commensaux : le cas de la souris domestique du rat noir au Sénégal / Parasite communities, immunity and invasion success of commensal rodents : the case of black rat and house mouse in Senegal.

Diagne, Christophe 11 December 2015 (has links)
Les invasions biologiques sont de plus en plus fréquentes, avec des conséquences importantes sur la biodiversité et la santé humaine. Étudier les mécanismes qui les expliquent permet simultanément (i) d’envisager des stratégies efficaces de contrôle et de prévention et (ii) d’étudier divers processus écologiques et évolutifs sur des échelles de temps contemporaines. Plusieurs hypothèses basées sur le parasitisme et l’immunité des hôtes sont proposées pour expliquer le succès des espèces envahissantes. Ainsi, au cours de l’invasion, les hôtes exotiques (1) perdraient leurs parasites naturels (Enemy Release, ER), (2) transfèreraient leurs parasites exotiques aux hôtes natifs (Spill-Over, SO) et/ou (3) amplifieraient les cycles des parasites natifs au sein des hôtes locaux (Spill-Back, SB). En relation avec ces changements dans les interactions hôtes-parasites, l’hypothèse EICA (Evolution of Increased Competitive Ability) prédit une modulation des ressources de l’hôte envahissant via un investissement moins important dans les réponses immunitaires coûteuses (inflammation) au profit de réponses immunitaires beaucoup moins coûteuses (réponses médiées par les anticorps) et de capacités de reproduction et de dispersion des populations sur le front d’invasion. Le but de ma thèse est de tester ces prédictions dans le cadre de deux invasions actuellement en cours au Sénégal : celles du rat noir Rattus rattus et de la souris domestique Mus musculus domesticus, deux espèces envahissantes majeures tant par leurs impacts (économique, sanitaire, écologique) que par leur distribution quasiment mondiale. Mes travaux se basent sur un dispositif d’échantillonnage en populations naturelles et sur le développement d’approches comparatives le long d’un gradient d’invasion pour chacune des deux espèces exotiques. Les patrons de structure (prévalence, abondance, richesse) de deux communautés de parasites (helminthes gastro-intestinaux, bactéries pathogènes) et les profils immunitaires (réponses médiées par les anticorps naturels, inflammation) des rongeurs commensaux exotiques (M. m. domesticus, R. rattus) et/ou natifs (Mastomys spp.) ont été comparés pour des localités situées dans des régions anciennement envahies (depuis plus de 100 ans), récemment envahies (depuis moins de 30 an : front d’invasion), et non envahies. Mes résultats montrent des variations dans la structure des communautés de parasites et les réponses immunitaires des hôtes natifs et exotiques. Les tendances observées, aussi bien pour les communautés de parasites que pour les composantes immunitaires étudiées le long des deux routes d’invasion, attestent de patrons globalement plus complexes qu’attendu sous les hypothèses de départ, suggérant l’existence de relations complexes entre caractéristiques des communautés d’hôtes et de parasites, investissement immunitaire, conditions environnementales et invasions biologiques. Des approches expérimentales doivent être envisagées afin de déterminer les conséquences et les mécanismes sous-jacents aux différents phénomènes observés. / Biological invasions are increasingly phenomenon worldwide having deleterious impacts on biodiversity and human health. Studying the mechanisms explaining them allows both (i) to define efficient strategies for controlling and preventing invaders and (ii) to study ecological and evolutionary processes at contemporary scales. Some major hypotheses rely on parasitism and host immunity to explain invasion success. Thus, exotic host populations (1) may benefit of an " Enemy Release " (ER) through impoverishment of their original parasite communities, and may affect native hosts by (2) transferring exotic parasites (Spill-Over, SO) and/or (3) by increasing transmission risk of native parasites (Spill-Back, SB). In turn, according to the refined “Evolution of Increased Competitive Ability” (EICA) theory, invasive populations should experience immune trade-offs by favouring less expensive antibody-mediated responses over costly inflammation, to increase their competitive ability (dispersion, reproduction). The aim of my thesis is to test these predictions along the invasion routes of two commensal exotic species in Senegal, the domestic mouse (Mus musculus domesticus) and the black rat (Rattus rattus). These rodent species are considered to be major invasive species worldwide inducing high economic, sanitary and ecological damages. My research is based on comparative analyses along one invasion route for each invasive species. We focused on gastrointestinal helminths and pathogenic bacteria as parasite communities, and inflammation and natural antibody-mediated responses as immune estimates. Comparisons were performed for invasive and/or native (Mastomys spp.) rodents between localities of long-established invasion (100-200 years ago), recent invasion (10-30 years ago; invasion front), and non-invaded localities. My findings showed variations along both invasion routes in parasite community structure and immune patterns, but in a more complex way than expected under the initial predictions. The heterogeneity of changes observed highlights the existence of particular relations between host and parasite traits, host immune investment, environmental conditions and biological invasions. Further experimental works are needed to assess the consequences and mechanisms underlying the changes observed along both invasion routes.
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Association between deworming during pregnancy and low birth weight. A secondary analysis of Pakistan Demographic Health Survey 2017-18.

Ali, Munazzah January 2020 (has links)
Abstract It is estimated that about 22% of all births in Pakistan are low birth weight (&lt;2500g), representing approximately 198,000 births per year. One of the major causes of low birth weight is maternal anemia. In Pakistan approximately 52% of pregnant women are anemic and one of the most common cause of maternal anemia is soil-transmitted helminthic infection. Soil-transmitted helminthiasis is endemic in Pakistan carries the highest burden of infection in Eastern Mediterranean region. Despite the recommendations deworming the mother during pregnancy is not being commonly practiced in routine antenatal care. We hypothesized that there is an association between deworming during pregnancy and low birth weight. For this study, cross sectional analysis of secondary data from the latest Pakistan Demographic Health Survey (PDHS conducted in 2017-18 and released in 2019) was done. Total N=1403 mother and child were included, logistic regression was used to determine the association between deworming during pregnancy and low birth weight after adjusting for potential confounders.  We found no statistically significant association [aOR 0.63, 95% CI (0.21-1.83)] between deworming during pregnancy and low birth weight. Moreover the mothers who belonged to higher socioeconomic status [aOR 0.41, 95% CI (0.22- .76)] and attained higher education [aOR 0.55, 95% CI (0.34- .87)] had reduced odds of having a new born with low birth weight compared to newborn of the women from low socioeconomic status and had no education, respectively. Further research is needed to explore effectiveness of deworming during pregnancy at population level.
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Development of machine learning models for object identification of parasite eggs using microscopy

Larsson, Joel, Hedberg, Rasmus January 2020 (has links)
Over one billion people in developing countries are afflicted by parasitic infections caused by soil-transmitted helminths. These infections are treatable with cheap and safe medicine that is widely available. However, diagnosis of these infections has proven to be a bottleneck by the fact that it is time-consuming, requires expensive equipment and trained personnel to be consistent and accurate. This study aimed to investigate the viability and performance of five machine learning models and a 'modular neural network' approach to localize and classify the following parasite eggs in microscopic images: Ascaris lumbricoides, Trichuris trichuria, Hookworm and Schistosoma mansoni. These models were implemented and evaluated on the Nvidia Jetson AGX Xavier to establish that they fulfilled the specifications of 95\% specificity and sensitivity, but also a speed requirement of 40000 images per 24 hours. The results show that R-FCN ResNet101 was the best model produced in this study, which performed the best on average. However, it did not fulfill the specifications entirely but is still considered a success due to being an improvement to the current implementation at Etteplan. Evaluation of the modular neural network approach would require further investigation to verify the performance of the system, but the results indicate it could be a possible improvement to the off-the-shelf machine learning models. To conclude, the study showed that the data and data infrastructure provided by Etteplan has proven to be a very powerful tool in training machine learning models to classify and localize parasite eggs in stool samples. However, expansion of the data to reduce the imbalance between the representations of the classes but also include more patient information could improve the training and evaluation process of the models.

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