Tesi sul tema "Bovine Trypanosomiasis"

The problem of controlling tsetse flies in Africa is an old one. The tsetse fly transmits the trypanosome parasites which cause sleeping sickness in humans and disease in cattle. Because cattle are a favoured food source for tsetse much work has been done looking at the use of insecticide treated cattle as a control strategy for the tsetse fly. Such treatment methods possess many advantages; they are safe and relatively environmentally benign, they can be applied by individual farmers without the need for logistically demanding and costly traditional control programmes and, in addition to tsetse flies the insecticides are effective against a wide range of other harmful cattle parasites. The cost of the insecticide is however a significant constraint to the number of livestock keepers who can afford to employ the technique and as a result many cattle remain untreated. Following the discovery that tsetse had a significant predilection for feeding on the legs and belly of cattle, it was hypothesised that restricting the insecticide to only those areas could offer comparable protection to treating the whole animal. Such an approach would use up to 80% less drug and thus make the treatment per animal much cheaper. In addition, preferentially targeting areas favoured by tsetse, and leaving the rest of the animal untreated, preserves some important ecological balances between cattle and their parasites which traditional treatment methods destabilise. This thesis describes the design, implementation and analysis of a longitudinal study run over 8 months in south east Uganda that sought to compare the effect of applying insecticide to cattle only on the regions favoured by tsetse flies. Cattle were recruited to the study and assigned one of four treatment groups; a whole body application of deltamethrin insecticide pour-on; a restricted application of deltamethrin spray, applied to the front legs, ears and belly; a prophylactic trypanocide injection of isometamidium chloride, and a control group, that received no further treatments. All animals in the study were however cleared using twin doses of a trypanocide diminazene aceturate at the start of the study.

The causes of anaemia in cattle were reviewed and it was postulated that trypanosomiasis or malnutrition were the main factors in affecting herd mean packed cell volume (PCV). In 1995/6 ˜ 18,000 cattle from 495 herds raised in the common tsetse fly belt of Zambia were examined haematologically, and PCV values were recorded with peripheral blood examined for trypanosomes via the buffy coat smear technique. Giemsa stained thick and thin dried blood smears (T&TS) were also examined. The results were entered into a tailor made Integrated Tsetse and Trypanosomiasis Database and were summarised as mean herd PCV, proportion of herd anaemic and parasitological prevalence. Using a linear regression model, ˜36% of the variance of the mean herd PCV could be accounted for by parasitological prevalence. A logistic regression of the data gave little improvement. The sensitivities of the buffy coat as well as T&TS examinations were calculated mathematically based on the Poisson distribution and these diagnostic techniques were reckoned to be probably more sensitive than previous work had suggested. The spatial distribution of bovine trypanosomiasis and the herd haematocrit values are displayed using a Geographical Information System (GIS). An indirect enzyme linked immunosorbent assay was developed for the detection of trypanosomal antibodies (Ab-ELISA) in serum using crude somatic antigen from T. congolense. The assay was further adapted to carry out tests using circles of dried blood held on filter paper. Inter and intra-assay sources of variation were investigated, as were the effects of sample storage and management. The assay was compared to the indirect fluorescent antibody test, and kinetics of anti-trypanosomal antibody were examined. Twelve thousand blood spot samples were assayed and the data were subject to a rigorous system of quality assurance, with the percentage positivity system of data expression being adopted.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-08T11:46:42Z No. of bitstreams: 1 Valeria Rosa dos Santos.pdf: 246353 bytes, checksum: da0bb55577698ef497d084dfe2ec9714 (MD5)
Made available in DSpace on 2016-11-08T11:46:42Z (GMT). No. of bitstreams: 1 Valeria Rosa dos Santos.pdf: 246353 bytes, checksum: da0bb55577698ef497d084dfe2ec9714 (MD5) Previous issue date: 2013-05-28
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The aim of this study was to evaluate the occurrence of Immunoglobulin G antibodies anti-Trypanosoma vivax in bovine cattle from the east region of Alagoas State, Brazil, and associate serum-positive frequency with epidemiologic data. For this purpose, a questionnaire was applied during the blood sampling. A total of 199 serum samples from four cities were submitted to Indirect Immunofluorescence Test (IIFT). Data were analyzed by Pearson´s chisquare test for a 5% significance level. The results showed that 23, 6% (47/199) of the samples were serum-positives for T. vivax. The frequencies, by municipalities varied from 10.1% to 41.2%. The chi-square values revealed an association between positive frequency and semi-intensive breeding as well with herd’s purpose double. It is concluded that preventive measures should be adopted.
No presente estudo objetivou-se detectar a ocorrência de anticorpos IgG anti-Trypanosoma vivax em rebanhos bovinos de propriedades rurais localizadas na Região Leste do estado de Alagoas e avaliar a associação da frequência de animais soropositivos com dados epidemiológicos. Foram testadas 199 amostras de soro sanguíneas de bovinos procedentes de quatro municípios, através da técnica de Reação de Imunofluorescência Indireta. Os dados foram analisados estatisticamente por meio do teste Qui-quadrado de Pearson, com nível de significância de 5%. Obteve-se 23,6% (47/199) de soropositividade com prevalência da infecção por T. vivax mais alta (p<0,05) em rebanhos com o sistema de criação semi-intensivo e de aptidão mista. Conclui-se em evidência sorológica por T. vivax como um agente circulante em rebanhos bovinos e que medidas preventivas e de controle devem ser adotadas.

Nigeria recently became the leading economy in Sub-Saharan Africa with a total GDP of 522.64 billion of US dollars (Tradingeconomics.com). As GDP increases, population rises and food demand intensifies. Within this context it is of critical importance to achieve food security. However, Nigeria heavily relies in exportations in order to meet the growing food demand, especially of meat products, a situation which is not desirable. The livestock industry, although one of the largest in Sub-Saharan Africa, still constrained by several endemic livestock diseases which result in annual economic loses for value of 140 million of US dollars (Fadiga et al., 2013). Within this group, bovine and porcine trypasosomiasis alone has been estimated to be responsible for 50 million of US dollars in economic loses in Nigeria (Fadiga et al., 2013). However, the real epidemiological situation, and hence the possibility of developing a rational control programme, remains largely unknown across the country due to the absence of large epidemiological studies. Majority of the trypanosomiasis research studies in Nigeria employ the Haematocrit technique or the Buffy coat technique and Giemsa stain as a diagnostic method. These techniques possess a high specificity but a much lower sensitivity than the molecular method employed in this research study. In fact, better epidemiological studies employing molecular techniques have been conducted in recent times such (Majekodumni et al., 2013a; Takeet et al., 2013) and results displayed much higher trypanosomiasis prevalence than previously detected by microscopy. In many sub-Saharan countries the majority of national livestock herds are owned by mobile communities; however, the trypanosome status of cattle owned by mobile pastoralist communities have been less thoroughly studied when compared to those of sedentary livestock keepers. In this doctoral work, the epidemiology of trypanosomiasis was studied, in transhumant herds located in two different Nigerian enclaves: the Kachia grazing reserve and the Jos Plateau, both located in North-central Nigeria. Within Kachia, the ecology appears to determine the presence of infection with a spatially differentiated distribution of the detected trypanosome species being observed across the reserve that appears not to be related to the migration of livestock. While upon the Jos Plateau, the current reduction in trypanosome prevalence suggests an abrupt change in the trypanosome infection rates in this part of the country. The hypothesis established in this doctoral work is that these epidemiologically different scenarios are the result of land pressures that have ultimately resulted in the habitat destruction of the vector. Longitudinal data was also collected in order to assess the effectivity of different formulations of synthetic pyrethroids for the combined control of trypanosomiasis and tick-borne diseases. Insecticide treated cattle represents at the moment the best long-term and cost-effective method for the control of the vector responsible for the transmission of trypanosomiasis, the tsetse fly. Since no data exist about the efficacy of the insecticide or the compliance of the pastoralist population with its application under migratory conditions, its performance was assessed in this doctoral work. In addition, animal health outcomes were monitored to stablish the possible relationship between clinical symptoms and disease outcome and socio-economic data relevant for the dynamics of disease such as migration trends, husbandry practices, awareness and administered treatment has been also analysed. The compiled information of this data will establish the risk associated with contracting the disease and provide further indications for the control of African bovine trypanosomiasis in the specific context of transhumant pastoral systems of sub-humid sub-Saharan African.

Orientador: Simone Baldini Lucheis
Resumo: A família Trypanosomatidae é composta por protozoários flagelados da ordem Kinetoplastidae. Os protozoários do gênero Trypanosoma, causadores das tripanossomíases e gênero Leishmania, causadores das leishmanioses, são os parasitos de maior interesse médico e veterinário As tripanossomíases são causadas por diferentes espécies, dentre elas: Trypanosoma cruzi, Trypanosoma. theileri, Trypanosoma equiperdum, Trypanosoma evansi e Trypanosoma vivax, sendo os três últimos de maior importância para os animais de produção, causando prejuízos econômicos para o setor agropecuário. Com o objetivo de avaliar a ocorrência de tripanosomatídeos no municipío de Bauru-SP, região endêmica para leishmaniose, foram avaliados 200 animais, sendo 100 bovinos (Bos taurus) e 100 equídeos (Eqqus spp.), procedentes de áreas urbanas e periurbanas do município. Para entender a distribuição de fatores de riscos na análise espacial, avaliou-se fatores epidemiológicos das leishmanioses, relacionados a seu diagnóstico nos animais de produção avaliados e também em cães e em humanos em diferentes bairros do município de Bauru, visando sua compreensão e integrá-las a estratégias de controle da doença. O diagnóstico dos animais foi baseado em técnicas parasitológicas: esfregaço sanguíneo e hemocultura; sorológicas: Reação de Imunofluorescência Indireta (RIFI) e Enzyme Linked Immunosorbent Assay (ELISA) e moleculares: Reação em Cadeia da Polimerase (PCR) e seqüenciamento. Não foram encontradas formas sugestivas de... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor

Submitted by MIRIAN DOS SANTOS PAIXÃO null (mirianspaixao@bol.com.br) on 2017-08-03T22:22:11Z No. of bitstreams: 1 Tese Final- Mirian dos Santos Paixão.pdf: 3906453 bytes, checksum: ebf95becc548ea4de5ab6f56f8c74757 (MD5)
Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-08-04T17:33:34Z (GMT) No. of bitstreams: 1 paixao_ms_dr_bot.pdf: 3906453 bytes, checksum: ebf95becc548ea4de5ab6f56f8c74757 (MD5)
Made available in DSpace on 2017-08-04T17:33:34Z (GMT). No. of bitstreams: 1 paixao_ms_dr_bot.pdf: 3906453 bytes, checksum: ebf95becc548ea4de5ab6f56f8c74757 (MD5) Previous issue date: 2017-07-10
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A família Trypanosomatidae é composta por protozoários flagelados da ordem Kinetoplastidae. Os protozoários do gênero Trypanosoma, causadores das tripanossomíases e gênero Leishmania, causadores das leishmanioses, são os parasitos de maior interesse médico e veterinário As tripanossomíases são causadas por diferentes espécies, dentre elas: Trypanosoma cruzi, Trypanosoma. theileri, Trypanosoma equiperdum, Trypanosoma evansi e Trypanosoma vivax, sendo os três últimos de maior importância para os animais de produção, causando prejuízos econômicos para o setor agropecuário. Com o objetivo de avaliar a ocorrência de tripanosomatídeos no municipío de Bauru-SP, região endêmica para leishmaniose, foram avaliados 200 animais, sendo 100 bovinos (Bos taurus) e 100 equídeos (Eqqus spp.), procedentes de áreas urbanas e periurbanas do município. Para entender a distribuição de fatores de riscos na análise espacial, avaliou-se fatores epidemiológicos das leishmanioses, relacionados a seu diagnóstico nos animais de produção avaliados e também em cães e em humanos em diferentes bairros do município de Bauru, visando sua compreensão e integrá-las a estratégias de controle da doença. O diagnóstico dos animais foi baseado em técnicas parasitológicas: esfregaço sanguíneo e hemocultura; sorológicas: Reação de Imunofluorescência Indireta (RIFI) e Enzyme Linked Immunosorbent Assay (ELISA) e moleculares: Reação em Cadeia da Polimerase (PCR) e seqüenciamento. Não foram encontradas formas sugestivas de protozoários em esfregaço sanguíneo, mas a análise de hemocultura de sete animais permitiu a visualização desses protozoários. Às técnicas sorológicas para Leishmania spp., 25% dos bovinos e 16% dos eqüídeos foram reagentes à RIFI e 24% dos equídeos e 6% dos bovinos reagentes ao ELISA. A PCR foi realizada a partir de amostras de sangue, hemocultura, suabes conjuntivais e ectoparasitos, com primers que amplificam a região ITS e HSP70. A partir de amostras de sangue, 23% dos bovinos e 6% dos eqüídeos foram positivos e sete amostras de hemocultura de bovinos foram positivas, com pelo menos um dos primers. As amostras de ectoparasitos e suabes não apresentaram positividade à PCR. Em amostras de bovinos positivas à PCR foram identificadas espécies do gênero Leishmania infantum, Leishmania donovani e Trypanosoma theileri e em amostras de eqüídeos, foram identificadas espécie do gênero Leishmania: Leishmania donovani. Os resultados obtidos às provas parasitológicas, sorológicas e/ou moleculares sugerem a presença de tripanosomatídeos em animais de produção do município no Bauru-SP. No presente estudo, pela análise espacial, sugere-se o papel de proteção dos animais de produção para a ocorrência de leishmaniose em humanos.
The family Trypanosomatidae is composed of flagellate protozoa of the order Kinetoplastida, divided into 10 genera. The Trypanosoma protozoa, which cause trypanosomiasis and Leishmania genus, which cause leishmaniosis, are the parasites of major medical and veterinary interest. Trypanosomiasis is caused by different species, among them: Trypanosoma cruzi, T. theileri, T. equiperdum, T . evansi and T. vivax, which affect production animals, causing economic damages to the agricultural sector. In order to evaluate the occurrence of trypanosomatids in the municipality of Bauru-SP, a region endemic for leishmaniosis, the present study evaluated 200 animals, 100 cattle (Bos taurus) and 100 equidae (Eqqus spp.) from urban and peri-urban areas of the municipality. In the spatial analysis, in order to understand the distribution of risk factors, we evaluated the epidemiological factors of leishmaniasis, related to its diagnosis in the studied animals, in dogs and in humans as well, from different districts of Bauru city, aiming a better comprehension and the strategies for the control of this disease. The diagnosis was based on parasitological techniques: blood smear and blood culture; serological tests: Immunofluorescence Antibody Test (IFAT) and Enzyme Linked Immunosorbent Assay (ELISA); and molecular: Polymerase Chain Reaction (PCR) and sequencing. No suggestive forms of protozoa were found in blood smears, but the blood culture analysis of seven animals allowed visualization of these protozoa. To the serological techniques for Leishmania spp., 25% of the cattle and 16% of the equines were reactive to IFAT and 24% of the equines and 6% of the cattle reactive to ELISA. PCR was performed from blood samples, blood cultures, conjunctival swabs and ectoparasites, with primers from the ITS and HSP70 region. From blood samples, 23% of cattle and 6% of equines were positive and seven samples of bovine blood culture were positive, with at least one of the primers. Samples of ectoparasites and swabs showed no PCR positivity. Specimens of the genus Leishmania infantum, Leishmania donovani and Trypanosoma theileri were identified in specimens of PCR positive bovines, and species of the genus Leishmania: Leishmania donovani were identified in equine samples. The results obtained for the parasitological, serological and / or molecular tests suggest the presence of trypanosomatids in animals of the municipality of Bauru-SP. In this study, by the spatial analysis, the role of protection of the production animals for the occurrence of leishmaniosis in humans is suggested.
FAPESP: 2014/15808-6

Made available in DSpace on 2014-06-11T19:31:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-23Bitstream added on 2014-06-13T18:41:54Z : No. of bitstreams: 1 teixeira_mca_dr_jabo.pdf: 2885202 bytes, checksum: 80086a83bb46ca2cb05bc1ae5ea75a8d (MD5)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Trypanosoma evansi é patogênico para a maioria dos animais, acometendo bovinos, bubalinos, caprinos, ovinos, suínos, cães, quatis, capivaras, camelos e outras espécies animais em áreas tropicais e subtropicais do globo terrestre sendo, no Brasil, a doença endêmica no pantanal mato-grossense. O presente estudo teve como fito principal estudar a evolução clínica, as alterações hematológicas, bioquímicas sérica, imunológicas e anatomopatológicas de bovinos infectados experimentalmente com T. evansi. Para tal, foram utilizados oito bovinos, clinicamente sadios e sorologicamente negativos para T. evansi. Três foram mantidos como testemunhos e cinco inoculados com T. evansi. Exames físicos, parasitológicos, hematimétricos e bioquímicos séricos (proteínograma, índice ictérico e glicose) e do líquido cefalorraquidiano foram realizados. Nos exames físicos realizados nos bovinos até 525° DAI não foi notada nenhuma anormalidade clínica com relação à temperatura retal, batimentos cardíacos, frequência respiratória, movimentos ruminais, aspectos de membranas mucosas (nasal, conjuntival, oral, vaginal e/ou prepucial) e dos linfonodos externos (mandibulares, maxilares, parotídeos, cervicais superficiais, sublíacos e mamários). A presença de tripomastigotas foi demonstrada através da prova biológica nos bovinos 01, 06 e 08 no15° DAI, bovinos 06 e 07 no 30° DAI, bovinos 01 e 06 no 45° DAI, bovino 06 no 60° DAI, bovino 01 no 75° DAI. As contagens de hemácias, os teores de hemoglobina e os volumes globulares dos bovinos, experimentalmente infectados, variaram dentro dos limites de normalidade para a espécie bovina. O VGM, HGM e CHGM, apresentam alterações pontuais.
Trypanosoma evansi are pathogenic to most of animals, affecting cattle, buffaloes, goats, sheep, pigs, dogs, coatis, capybaras, camels and other animals in tropical and subtropical areas of the globe, and, in Brazil, it causes an endemic disease in the Pantanal Mato Grosso. This study primarily aimed to study the clinical, hematological, biochemical, immunological and pathological alterations in cattle experimentally infected with T. evansi. For this purpose, we used eight animals, clinically healthy and serologically negative for T. evansi. Three animas were kept as evidence and five were inoculated with T. evansi. Physical, parasitological, hematological and serum biochemical (proteins, icteric index and glucose) and cerebrospinal fluid examination were performed. In the physical examination conducted in cattle up to 525th DAI were not observated any clinical abnormality in concerning rectal temperature, heart rate, respiratory rate, ruminal movements, aspects of the mucous membranes (nasal, conjunctival, oral, vaginal and / or specimen) and external nodes (mandibular, maxillary, parotid, superficial cervical, breast and sublíacos). The presence of trypomastigotes was demonstrated by bioassay in cattle 01, 06 and 08 no 15th DAI, cattle 06 and 07 at 30° DAI, cattle 01 and 06 on the 45 th DAI, cattle 06 in 60 th DAI, cattle 01 in 75 th DAI. Red blood cells counts, hemoglobin content and volume cell of experimentally infected cattle were within normal limits for the bovine species. The MCV, MHC and MCHC, showed specific changes. Physical examination of the cerebrospinal fluid did not show alterations in appearance and coloration. Morever, using the Giensa-stained blood smears, buffy coat technique (BCT) and mouse inoculation procedure were negative for T. evansi tripomastigote. Serum protein concentrations, identified 26 proteins with molecular weights ranging from 20 to 245 KD.

Trypanosoma vivax est l’un des principaux parasites responsables de la Trypanosomose Animale Africaine. Malgré son impact considérable, il est très peu étudié et on déplore l’absence d’outil permettant la recherche sur ce parasite, comme un modèle murin robuste ou des conditions permettant sa culture in vitro et sa transgénèse. Nous avons identifié chez T. Vivax, la présence d’une proline racémase (PRAC), homologue de la TcPRAC, un mitogène et un facteur de virulence de T. Cruzi découvert et caractérisé au laboratoire. Nous avons donc développé tous les outils pour déterminer le rôle de cette protéine chez T. Vivax. Nous avons établit un modèle murin d’infection à T. Vivax présentant les caractéristiques majeures des bovins affectés: une anémie sévère, des lésions macroscopiques au niveau du foie et de la rate ainsi que des œdèmes au cerveau, le tout aboutissant à la mort de l’animal. Nous avons mis au point la culture axénique de ce parasite sous sa forme épimastigote, construits des vecteurs spécifiques de T. Vivax et définis des conditions de transfection permettant l’obtention des premiers transfectants de T. Vivax génétiquement modifiés de façon stable. La création d’une souche exprimant la luciférase nous a permis de consolider le fait que T. Vivax est capable de franchir la barrière hémato-encéphalique durant la phase tardive de l’infection. Enfin, nous avons inactivé les gènes TvPRAC par recombinaison homologue (∆TvPRAC) et avons pu montrer que la TvPRAC est impliquée chez tous les stades évolutifs de T. Vivax et peut être définie comme facteur de virulence parasitaire, la moitié des souris infectées avec la souche ∆TvPRAC étant capable de contrôler l’infection
Trypanosoma vivax is one of the leading parasites responsible for African Animal Trypanosomiasis in Africa and Latin America. Despite its impact, T. Vivax is largely ignored and we deplore the lack of tool for the research on this parasite, such as a robust mouse model or conditions for in vitro culture and transgenesis. We have identified in T. Vivax, the presence of a proline racemase (PRAC), homologous to the TcPRAC, a mitogen and a virulence factor of T. Cruzi discovered and characterized in the laboratory. In this thesis, we describe the development of the tools that allowed us to determine the role of this protein for T. Vivax. We have established a murine model of infection with T. Vivax exhibiting all the major characteristics of affected cattle: the severe anemia, the gross lesions in the liver and spleen and brain edema, the overall leading to the death of the animal. We developed the axenic culture of the epimastigote forms of this parasite, constructed specific vectors for T. Vivax and defined the conditions of transfection to obtain the first T. Vivax genetically modified stably. Remarkably, the transfected parasites are still able to infect immunocompetent mice. The construction of a strain expressing luciferase allowed us to consolidate that T. Vivax is capable of crossing the blood-brain barrier during the late phase of infection. Finally, we inactivated the TvPRAC genes by homologous recombination (ΔTvPRAC) and were able to demonstrate that the TvPRAC is involved in all developmental stages of T. Vivax and can be defined as a parasite virulence factor, half of the mice infected with the ΔTvPRAC strain being capable to control the infection

Orientador: Luiz Carlos Marques
Banca: Rosangela Zacarias Machado
Banca: Fabiano Antonio Cadioli
Banca: Percílio Brasil dos Passos
Banca: Thais Helena Constantino Patelli
Resumo: Trypanosoma evansi é patogênico para a maioria dos animais, acometendo bovinos, bubalinos, caprinos, ovinos, suínos, cães, quatis, capivaras, camelos e outras espécies animais em áreas tropicais e subtropicais do globo terrestre sendo, no Brasil, a doença endêmica no pantanal mato-grossense. O presente estudo teve como fito principal estudar a evolução clínica, as alterações hematológicas, bioquímicas sérica, imunológicas e anatomopatológicas de bovinos infectados experimentalmente com T. evansi. Para tal, foram utilizados oito bovinos, clinicamente sadios e sorologicamente negativos para T. evansi. Três foram mantidos como testemunhos e cinco inoculados com T. evansi. Exames físicos, parasitológicos, hematimétricos e bioquímicos séricos (proteínograma, índice ictérico e glicose) e do líquido cefalorraquidiano foram realizados. Nos exames físicos realizados nos bovinos até 525° DAI não foi notada nenhuma anormalidade clínica com relação à temperatura retal, batimentos cardíacos, frequência respiratória, movimentos ruminais, aspectos de membranas mucosas (nasal, conjuntival, oral, vaginal e/ou prepucial) e dos linfonodos externos (mandibulares, maxilares, parotídeos, cervicais superficiais, sublíacos e mamários). A presença de tripomastigotas foi demonstrada através da prova biológica nos bovinos 01, 06 e 08 no15° DAI, bovinos 06 e 07 no 30° DAI, bovinos 01 e 06 no 45° DAI, bovino 06 no 60° DAI, bovino 01 no 75° DAI. As contagens de hemácias, os teores de hemoglobina e os volumes globulares dos bovinos, experimentalmente infectados, variaram dentro dos limites de normalidade para a espécie bovina. O VGM, HGM e CHGM, apresentam alterações pontuais.
Abstract: Trypanosoma evansi are pathogenic to most of animals, affecting cattle, buffaloes, goats, sheep, pigs, dogs, coatis, capybaras, camels and other animals in tropical and subtropical areas of the globe, and, in Brazil, it causes an endemic disease in the Pantanal Mato Grosso. This study primarily aimed to study the clinical, hematological, biochemical, immunological and pathological alterations in cattle experimentally infected with T. evansi. For this purpose, we used eight animals, clinically healthy and serologically negative for T. evansi. Three animas were kept as evidence and five were inoculated with T. evansi. Physical, parasitological, hematological and serum biochemical (proteins, icteric index and glucose) and cerebrospinal fluid examination were performed. In the physical examination conducted in cattle up to 525th DAI were not observated any clinical abnormality in concerning rectal temperature, heart rate, respiratory rate, ruminal movements, aspects of the mucous membranes (nasal, conjunctival, oral, vaginal and / or specimen) and external nodes (mandibular, maxillary, parotid, superficial cervical, breast and sublíacos). The presence of trypomastigotes was demonstrated by bioassay in cattle 01, 06 and 08 no 15th DAI, cattle 06 and 07 at 30° DAI, cattle 01 and 06 on the 45 th DAI, cattle 06 in 60 th DAI, cattle 01 in 75 th DAI. Red blood cells counts, hemoglobin content and volume cell of experimentally infected cattle were within normal limits for the bovine species. The MCV, MHC and MCHC, showed specific changes. Physical examination of the cerebrospinal fluid did not show alterations in appearance and coloration. Morever, using the Giensa-stained blood smears, buffy coat technique (BCT) and mouse inoculation procedure were negative for T. evansi tripomastigote. Serum protein concentrations, identified 26 proteins with molecular weights ranging from 20 to 245 KD.
Doutor

L'élevage bovin en RCA est constitué essentiellement de zébus Mbororo trypanosensibles. Leur activité pastorale, s'articulant autour de trois domaines (aire de repos, abreuvoir et pâturage), les expose à trois espèces de trypanosomes : T. Congolense, T. Vivax et T. Brucei. Au centre du pays, en rapport probable avec le mode de conduite pastorale, les prévalences sont plus faibles chez les veaux que chez les adultes mais sont comparables chez les taureaux et chez les vaches. Glossina fuscipes fuscipes Newstead 1910, espèce inféodée aux galeries forestières et opportuniste sur le plan trophique, héberge au moins cinq espèces de trypanosomes : T. Grayi, T. Simiae, T. Congolense, T. Vivax et T. Brucei. Le taux d'infections matures des trois derniers est de 0,60%. Cette glossine est considérée comme le vecteur principal de ces parasites en les transmettant aux bovins, au niveau des abreuvoirs. Les stomoxes, en particulier Stomoxys Nigra Macquart 1851, seraient des vecteurs accessoires, en assurant une transmission mécanique de ces trypanosomes, au niveau de l'aire de repos du bétail. Le piège bipyramidal, utilisé dans ce travail pour l'échantillonnage des populations de Glossina fuscipes fuscipes, est également un excellent outil de lutte contre cette glossine. Disposé à l'abreuvoir, il en abaisse les densités et rajeunit ses populations. La conséquence directe est une baisse des prévalences trypanosomiennes bovines (6,37% contre 16,63% en l'absence de piégeage)

Les trypanosomoses animales africaines transmises par les glossines sont une des principales contraintes pathologiques au développement et à l’intensification de l’élevage en Afrique sub-saharienne. Leur contrôle repose sur deux grandes stratégies : la lutte autonome par les éleveurs qui vise à contrôler la maladie de manière à permettre une production rentable, et l’intervention étatique centralisée qui vise dans la plupart des cas l’éradication du vecteur et de la maladie. Cette seconde stratégie s’est amplifiée récemment dans le cadre de la campagne pan-africaine d’éradication des glossines et des trypanosomoses (PATTEC), coordonnée par l’Union Africaine. Je me suis attachée à caractériser les capacités d’innovation des éleveurs face au risque de santé animale et réciproquement à l’effet du contrôle du risque sur les trajectoires d’innovation des éleveurs. Le terrain d’étude a concerné deux pays d’Afrique de l’Ouest: le Burkina Faso et le Sénégal. Au Sénégal, nous avons développé une approche coûts-bénéfices originale d’un projet d’éradication, et montré que les bénéfices attendus dépendent essentiellement de l’innovation, grâce aux gains de productivité dus à la transition des systèmes d’élevage utilisant la race Djakoré trypanotolérante vers des systèmes d’élevage améliorés utilisant des races plus productives trypanosensibles. Au Burkina Faso (bassin du Mouhoun), les objectifs étaient de caractériser la perception du risque par les éleveurs, les stratégies autonomes de lutte et leurs capacités à adopter une nouvelle méthode de lutte contre les glossines, le pédiluve insecticide. Enfin, pour comprendre et anticiper l’impact de l’évolution du risque trypanosomien sur les trajectoires d’innovation des éleveurs et améliorer l’évaluation économique de la campagne d’éradication au Sénégal, une analyse croisée de 10 études de cas a permis d’identifier puis de caractériser les dynamiques locales d’innovation, les logiques d’action et les indicateurs de capacités d’innovation des différents groupes d’éleveurs. Dans les deux sites d’étude, le dynamisme des réseaux socio-techniques auxquels appartiennent les éleveurs et leurs manières de le mobiliser permettent de comprendre l’impact de ce risque sanitaire sur les capacités d’innovation des éleveurs. Ces processus ont été étudiés en mobilisant une théorie de l’innovation, la SAR (sociologie de l’Acteur-Réseau) et en combinant des méthodes d’enquêtes par questionnaire, d’épidémiologie participative et une analyse compréhensive socio-technique inspirée de la méthode du GERDAL (Groupe d’Expérimentation et de Recherche, Développement et Actions Localisées). En perspective, les avancées liées à ce travail dans le domaine de l’hybridation des sciences vétérinaires et sociales sont discutées, et des pistes d’amélioration possibles sont proposées. Un des principaux enseignements de cette thèse est d’ordre méthodologique : une piste est proposée pour l’hybridation de méthodes d’épidémiologie participative et d’une analyse compréhensive socio-technique basée sur les apports de la SAR et du GERDAL
African animal trypanosomosis, transmitted by tsetse flies, are among the main animal health constraints to the development and intensification of cattle production in sub-Saharan Africa. Their control relies on two major strategies: the farmer-based control aiming at controlling the disease in order to allow a cost-effective production, and the centralized state intervention mostly targeting the eradication of the vector and the disease. This second strategy recently spread in the framework of the Pan African Tsetse and Trypanosomosis Eradication Campaign (PATTEC), coordinated by the African Union. I aimed to characterize the innovation capacities of livestock producers facing this animal health risk and vice versa the effect of risk control on innovation trajectories of livestock farmers. The study area concerned two west african countries: Burkina Faso and Senegal. In Senegal, we developed an original cost-benefit approach of the eradication program, and showed that the expected benefits mainly relie on innovation, thanks to the productivity benefits resulting from the shift from livestock breeding systems using the trypanotolerant Djakoré breed toward improved livestock breeding systems using more productive trypanosensible cattle breeds. In Burkina Faso (Mouhoun basin), the goals were to characterize the risk assessment by livestock producers, farmer-based control strategies and their capacities to adopt a new control method against tsetse flies, the insecticide footbath. At last, in order to understand and predict the impact of the evolution of the trypanosomosis risk on innovation trajectories of livestock producers and to improve the economic analysis of the eradication campaign in Senegal, a cross-sectional analysis of 10 case studies allowed identifying and characterizing the local dynamics of innovation, the rationales for action and the indicators of innovation capacities of the different groups of livestock producers. In the two study areas, the dynamism of socio-technical networks which livestock farmers belonged to and the ways they were mobilized allowed to understand the impact of this animal health risk on innovation capacities of the livestock producers. These processes were studied by mobilizing an innovation theory, the ANT (Actor Network Theory) and combining inquiry methods by questionnaires, methods of participatory epidemiology and a comprehensive socio-technical analysis inspired from the GERDAL’s method (Groupe d’Expérimentation et de Recherche, Développement et Actions Localisées). In perspective, advances linked to this work in the field of the hybridization between veterinary and social sciences are discussed, and few potential ways of improvement are proposed. One of the mains learning of this thesis is about methods: a pathway is proposed for hybridization of methods of participatory epidemiology and a comprehensive socio-technical analysis based on the inputs of SAR and GERDAL methods

The aim of this thesis was to provide a picture of the trypanosomosis and drug resistance prevalence in Eastern Province of Zambia, to understand the underlying factors of drug resistance (drug use habits), to improve the diagnosis of trypanosomosis in livestock and finally, to improve the diagnosis of isometamidium resistance in T.congolense. After an introductory part where available trypanosomosis and trypanocide resistance diagnostic methods are described and discussed, the body of the thesis is divided in two main sections. In the first section are presented the results of a cross-sectional and a longitudinal epidemiological survey describing the geographical distribution of trypanosomosis cases, of resistant isolates and of cattle treated with isometamidium chloride. The results of the monitoring of unsupervised treatments of cattle with isometamidium by farmers and veterinary assistants with the Isometamidium-ELISA technique are also presented. The second section describes the development of two new diagnostic methods, the first one allowing the diagnosis of trypanosome infections with high sensitivity and specificity through semi-nested polymerase chain reaction and restriction fragment length polymorphism. This is the first report of a pan-trypanosome PCR test (a single PCR test for the diagnosis of all important pathogenic trypanosomes of cattle). The second new method that was developed allows the diagnosis of isometamidium resistant T.congolense strains by PCR-RFLP. This is the first report of a PCR based diagnostic test of trypanocide resistance in T. congolense.

Doctorat en sciences, Spécialisation biologie moléculaire
info:eu-repo/semantics/nonPublished