Enteric caliciviruses were detected in humans and animals incoming into food chain such as porcine and bovine species. Caliciviruses have a single stranded, positive, polyadenylated RNA genome. They share properties of high environmental stability, high excretion load and high genetic variation linked to point mutations and recombination. These properties have allowed the formulation of hypothesis about zoonotic transmission or animal reservoir for human strains. The aim of the thesis, composed of four studies, was to investigate the zoonotic risk associated to animal enteric caliciviruses. In a first study, circulation of both sapoviruses and noroviruses was evidenced by molecular detection in Belgian pig farms. They were detected in both asymptomatic animals or in piglets showing clinical signs of enteritis. In a second study, bovine noroviruses were molecularly detected in Belgian cattle. Strains phylogenetically related to those of the genotype 2 were predominant. In the same study, seroprevalence against bovine norovirus infection in cattle was investigated by indirect ELISA. Antigens included in the ELISA were virus-like particules obtained in the baculovirus system by expressing the capsid protein of a strain isolated by the laboratory during a previous study. Apparent seroprevalence was high (93.2%), confirming previous results about apparent molecular prevalence in diarrheic calves (7.5%). In a third study about molecular detection of bovine noroviruses, diagnostic strategy was revised in order to improve the detection of genotype 1 strains and to deal with opportunity of recombination events. Bovine norovirus recombinant strains and also, surprisingly, some sequences genetically related to bovine kobuviruses were detected. In a fourth study, attachment factors and internalization pathways for genotype 2 bovine noroviruses were studied with an original quantitative method based on flow cytometry analysis. Along with a galactosyl residue that seems to be essential, a sialic acid residue was also showed to be implied in the binding of genotype 2 bovine noroviruses or in a posterior step. Internalisation pathways related to lipid rafts and to macropinocytosis were found. Together the results have contributed to the analysis of the zoonotic risk associated to enteric animal caliciviruses in the Belgian epidemiological situation. According to these results, the zoonotic risk seems to be low as no sequences genetically related to the human ones were detected. However, some results suggest to maintain a certain degree of vigilance. Indeed, molecular detection showed the co circulation of both bovine and porcine noroviruses in Belgian farms, implicating that hazard exposition exists and could be high in the Belgian epidemiological situation. Morevover, circulation of recombinant strains in the overall population of the bovine norovirus strains implies that this phenomenon was included in the risk assessment. Infection pressures and high prevalences for human and animal strains in a closed epidemiological context as the Belgian one could increase the risk of interspecific recombination. Finally, the sialic acid residue, possibly involved in the binding of genotype 2 bovine noroviruses, and a poorly specific internalisation pathway as macropinocytosis could also favor interspecies barrier crossing. In the current knowledge, zoonotic risk associated to animal enteric caliciviruses can be communicated as low but a degree of vigilance has to be retained, associated for example to observation of genetic evolution in the populations of human and animal strains.

L'encéphalopathie spongiforme bovine (ESB) est une maladie neuro-dégénérative fatale affectant les bovins ; elle est également une zoonose à l'origine du variant de la maladie de Creutzfeldt-Jakob. Identifiée pour la première fois au Royaume-Uni en 1986, cette maladie s'est rapidement étendue en Europe, malgré la mise en place de mesures de contrôle. En raison des particularités épidémiologiques de l'ESB (longue période d'incubation, âge précoce à l'infection et diagnostic post-mortem possible uniquement en fin d'incubation), l'évolution temporelle de l'exposition des bovins à l'ESB ne peut être appréhendée qu'à partir de la modélisation. Nous avons utilisé le modèle Age-Période-Cohorte afin de (ré)évaluer, en relation avec les principales mesures de contrôle, l'évolution de l'épizootie d'ESB à la lumière des données de surveillance les plus récente, en France, et dans six autres pays européens : Allemagne, Irlande, Italie, Pays-Bas, Pologne et Royaume-Uni.

Made available in DSpace on 2014-06-11T19:27:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-23Bitstream added on 2014-06-13T18:55:50Z : No. of bitstreams: 1 nunes_jor_me_jabo.pdf: 1573295 bytes, checksum: 55a5cc5a8fd3d59d09557d2948d6bd19 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O convívio do ser humano com cães e gatos tem se intensificado sem a devida adoção de posturas de posse responsável. O presente trabalho teve propósito de contribuir com os estudos da dinâmica populacional de cães e gatos em Jaboticabal, São Paulo, e avaliar o nível de conhecimento das pessoas sobre posse responsável e zoonoses. A obtenção de dados foi feita em dois bairros da periferia, nos anos 2005 e 2010, por meio de questionários. No Bairro Residencial entrevistaram-se 228 moradores em 2005 e, em 2010, foram re-entrevistados 196. No Bairro Jardim Boa Vista foram 111 em 2005, e 84 em 2010. Foram realizados a Análise de Correspondência Múltipla e o Geoprocessamento. Obteve-se um alto número de animais com livre acesso às ruas, na maioria machos e principalmente gatos. Esses animais podem ser computados como semi-restritos ou de vizinhança, com possibilidade de causar transtornos. Além de já estarem em número elevado, os animais de rua têm respaldo da comunidade, que os alimenta, dando condições para que perpetuem. Existe um programa de castração no Município, mas a população de cães e gatos continua crescendo, pois o número de animais castrados ainda é pouco expressivo. Do ano de 2005 para 2010, houve aumento significativo da quantidade de cães idosos, principalmente fêmeas; isso pode ser reflexo da postura das pessoas de maiores cuidados com os animais. As informações obtidas em muito contribuirão para que seja estabelecida a dinâmica da população de cães e gatos em todo Município de Jaboticabal. Certamente, isto dará um suporte valioso ao Serviço Municipal de Saúde para o planejamento e a adoção de medidas mais adequadas de controle de populações animais e de zoonoses / The interaction of humans with dogs and cats has increased without proper postures of responsible ownership. The purpose of this study was to contribute to studies of population dynamics of dogs and cats in Jaboticabal, São Paulo, and assess the level of knowledge of the community about responsible ownership and zoonoses. The data collection was done with two neighborhoods, in the years 2005 and 2010, using questionnaires. In the Neighborhood Residential 228 residents were interviewed in 2005 and 196 residents were re-interviewed in 2010. In Jardim Boa Vista 111 residents were interviewed in 2005 and 84 in 2010. We performed a Multiple Correspondence Analysis and GIS. We obtained a high number of animals witch has free access to the streets, mostly male and cats. These animals could be classified as semi-restricted or neighborhood, with the possibility of causing trouble. In addition, besides the high number of animals, the street animals have the support of the community that provide food to them, giving conditions to perpetuate. There is a castration program in the city, but the cats and dogs population continues to grow due to the fact that the number of castrated animals is still small. From 2005 to 2010, there was a significant increase in the number of older dogs, especially female; this may reflect the attitude of the community to be more careful with animals. The information obtained will contribute greatly to the setting of a dynamic population of dogs and cats throughout Jaboticabal. Certainly, it will provide valuable support to the Municipal Health Service for planning and adoption of suitable measures to control animal populations and zoonoses

Les Henipavirus sont des paramyxovirus zoonotiques émergents hautement pathogènes. Ils sont capables d’infecter un large spectre d’hôtes incluant notamment la chauve-souris frugivore (réservoir naturel), le porc et l’homme. Etant donné leur très grande dangerosité et en l’absence de traitements curatifs ou prophylactiques efficaces, ces virus doivent être manipulés dans un laboratoire de classe P4. Dans une première partie, nous étudions l’effet de composés glyco-amino-glycanes sur l’infection par les Henipavirus ainsi que leur potentielle application en tant que traitement. Dans une seconde partie, nous nous attachons à comprendre les interactions entre le système immunitaire de l’hôte et le virus. Afin de mieux comprendre ces interactions, nous avons utilisé une approche basée sur l’utilisation de souris déficientes pour certaines voies de l’immunité. En effet, bien que les récepteurs cellulaires au virus (EFN B2 et B3) soient fonctionnels chez la souris, celle-ci est résistante à l’infection par voie intrapéritonéale. Nous avons analysé la susceptibilité au virus Nipah (NiV) de souris privées de différentes voies du système immunitaire inné et adaptatif. Les résultats obtenus permettent d’envisager certaines lignées de ces souris comme nouveaux modèles animaux pour l’étude de l’immunopathogénèse du NiV. Cette étude suggère aussi que le système interféron de type I joue un rôle crucial dans la limitation de la propagation virale vers le cerveau et que les lymphocytes T sont nécessaires à la complète élimination du virus. Les macrophages jouent, quant à eux, un rôle central et indispensable, à l’interface entre système inné et adaptatif. Enfin, nous abordons les prémices d’un projet visant à identifier les différences d’interactions au niveau moléculaire entre les protéines non-structurales du virus et les protéines du système immunitaire inné chez l’Homme et la souris afin de voir s’il se dégage des différences d’interactions pouvant expliquer les différences de pathogénie. Ces travaux ont donc permis d’identifier de nouveaux modèles animaux et de mieux caractériser les interactions entre le pathogène et le système immunitaire de l’hôte, de l’échelle moléculaire à l’échelle de l’organisme entier. Néanmoins, les mécanismes précis de ces interactions restent à élucider et permettront certainement de mieux comprendre la grande diversité de pathogénie des Henipavirus. / Henipaviruses are highly pathogenic emerging zoonotic paramyxoviruses. They can infect a broad spectrum of mammals including flying foxes (Pteropus fruit bats), its reservoir, pigs and humans. As there are neither therapeutic drugs nor efficient prophylactic treatment towards these highly lethal viruses, they have to be manipulated in biosafety level-4 laboratories. In the first part of this thesis, we study the role of glyco-amino-glycans on Henipavirus infection and their potential use as treatment. In the second part, we describe the interaction between the host immune system and the pathogen. To investigate these interactions, we took advantage of different transgenic mouse models deficient for some immune pathways. Indeed, although mice possess the viral entry receptor for Henipaviruses, they do not succumbed to intraperitoneal infection. We analyzed the susceptibility to Nipah virus (NiV) infection of mice deleted for different components of innate and adaptive immune systems. Obtained results showed that some of these mice can be used as new models for NiV immunopathogenesis study. This study also suggests that type I interferon system plays a major role in limitation of viral spreading to the brain and that T cells are necessary for full viral clearance. Macrophages act at the crossroad of immunity, between innate and adaptive system. Finally, we deal with the preliminary phases of a project which aims to identify the differences, at a molecular level, of interaction between non-structural viral proteins and innate immunity proteins in mice and human. Such differences could explain the different clinical patterns that are observed in these species. In conclusion, this thesis allowed to identify new animal models and to better characterize host-pathogen interactions, from molecular to whole organism level. However, the precise mecanisms of these interactions remain to be elucidated and would probably help to understand the great diversity of pathogeny of Henipaviruses.

De nombreux primates d'Afrique sont infectés par les SIV et SLTV en particulier par ceux reconnus comme les ancêtres du VIH et HTLV à l'origine de graves épidémies chez l'homme. Des humains en Afrique continuent d'être exposés à ces virus lors des activités liées à la chasse. Ainsi le risque de transmissions inter-espèces des rétrovirus des primates aux humains persiste toujours dans cette région. Nous avons montré que le mangabey agile est infecté par un SIVagi phylogénétiquement très proche du SIVrcm infectant le mangabey à collier blanc au Cameroun. Nous avons montré aussi que les SIVdeb infectant les cercopithèques de Brazza se regroupent phylogénétiquement selon leurs régions géographiques d'origine non seulement à travers l'Afrique Equatoriale mais aussi à l'intérieur même du Cameroun. Nous avons adapté et validé un outil sérologique (Luminex) qui permet de tester près de 34 antigènes SIV/HIV simultanément. Cet outil et d'autres nous ont permis ensuite de documenter une prévalence globale élevée d'infection SIV et STLV chez les singes chassés pour la viande de brousse en RDC, particulièrement chez les espèces les plus consommées. De nouvelles lignées de SIV et STLV ont aussi été décrites. Par ailleurs, nous avons montré pour la première fois que les fécès peuvent être utilisés pour la détection des STLV chez les bonobos qui sont naturellemnt infectés par les STLV-2 et 3. En revanche, aucune évidence d'infection SIV chez les bonobos n'a été observée. Les travaux de cette thèse contribuent à l'amélioration des connaissances sur les infections rétrovirales chez les primates non humains au Cameroun et en RDC, complètent les informations disponibles sur les réservoirs du VIH-1 et HTLV et enfin fournissent des éléments d'appréciation du risque de transmission de ces virus à l'homme en RDC et au Cameroun. / SIVs and SLTVs infecting apes and monkeys in Africa are the progenitors of HIV and HTLV. Numerous African non-human primates are infected with SIV and STLV and humans continue to be exposed to these viruses by hunting and handling of primate bushmeat. Therefore the risk of cross-species transmissions from primates to humans is still persistent. We showed that SIVagi infecting captive agile mangabey is most closely related to SIVrcm from a wild-caught red capped mangabey from Cameroon. We observed also phylogeographic clustering among SIVdeb strains from Cameroon, DRC and Uganda, but also among distinct areas in Cameroon. We adapted and evaluated a novel high troughput immune assay that included 34 different HIV and SIV antigens in a single well. Using this tool and others, we found a high SIV and STLV prevalence especially among the most hunted monkeys in DRC. We identified also new SIV and STLV lineages. On the other hand, we did not find any evidence of SIV infection in bonobos. However, we showed, for the first time, that fecal samples could be used to detect STLV infection in bonobos that are naturally infected with STLV-2 and 3. The results obtained during this thesis contribute to the improvement of our knowledge on retroviral infections in nonhuman primates from Central Africa, complete information on HIV and HTLV reservoirs and provide background information on human transmission risk of these infections in central Africa especially in DRC.

Le virus de l'influenza aviaire hautement pathogène (IAHP) de sous-type H5N1 a causé de nombreuses pertes humaines, animales et économiques à travers le monde, notamment en Asie du Sud-Est. Son potentiel pandémique est une source d'inquiétude majeure en santé publique. Au Cambodge, l'infection est enzootique, et a causé la mort de 16 personnes depuis sa première détection en 2004 dans le pays, dont 8 pour la seule année 2011. Bien que l'hypothèse de la transmission directe hôte-hôte (animal-animal ou animal-homme) soit privilégiée, de récentes études semblent clairement incriminer certains éléments constitutifs de l'environnement dans le cycle de transmission du virus. Cependant, peu de données sont actuellement disponibles sur le sujet. Le travail de cette thèse a consisté en grande partie à apporter quelques réponses aux nombreuses questions soulevées. Des méthodes de détection du virus H5N1 dans l'environnement ont été mises au point, validées, et utilisées pour la détection de virus dans des prélèvements environnementaux collectés sur des sites d'épizooties au Cambodge. Le rôle de passereaux, capturés pour la réalisation de certains rituels bouddhistes en Asie, dans la dissémination du virus aux populations aviaires et humaines, a également été étudié. En parallèle, des données importantes du mode d'évolution du virus H5N1 au sein d'hôtes aviaires, jusqu'alors inexistantes, ont été apportées par l'étude des quasi-espèces du virus. L'ensemble des résultats rassemblés dans cette thèse souligne l'importance du rôle de l'environnement dans la dissémination et la transmission du virus IAHP H5N1. / The Highly Pathogenic Avian Influenza (HPAI) virus, subtype H5N1, has caused important human, animal and economical and losses in all countries affected, especially in Southeast Asia. Its pandemic potential is a major public health concern. In Cambodia, the infection is enzootic, and has caused 16 human fatalities since its first detection in the country in 2004, out of which 8 occurred in 2011. Although the hypothesis of direct host-to-host (animal-to-animal or animal-to-human) transmission is commonly accepted, recent studies clearly identified some environmental components as sources for avian and/or human contamination with H5N1 virus. Nonetheless, only few data are currently available on this topic. The work presented in this thesis aimed at better describing the role of the environment in the transmission cycle of the H5N1 virus. H5N1 virus detection methods in the environment were designed, validated and used for the detection of virus in environmental samples collected during epizootic outbreaks in Cambodia. The role of the Merit Release Birds, used during some common Buddhist rituals in Asia, in the dissemination of the virus to avian and human populations was also studied. In parallel, important and novel data regarding the evolution of the H5N1 virus within avian hosts were provided by quasi-species studies. The findings described in this thesis emphasize the relevance of the role of the environment in the dissemination and transmission of the HPAI H5N1 virus.

Campylobacter est responsable de la zoonose bactérienne d’origine alimentaire la plus fréquemment reportée en Europe. Cette bactérie étant ubiquitaire, les sources et voies d’infection de l’Homme sont nombreuses. Cependant, afin de diminuer l’incidence de la maladie, il est nécessaire d’identifier les principaux réservoirs impliqués dans les infections humaines. Pour cela, nous avons dans un premier temps investigué la présence de Campylobacter dans trois réservoirs animaux (volaille, bovin, animaux de compagnie), ainsi que la diversité génétique des isolats de C. jejuni, en comparaison à celle d’isolats cliniques, à l’aide des techniques MLST (Multilocus sequence typing) et CGF (Comparative Genomic Fingerprinting). Afin d’identifier l’origine des campylobactérioses avec précision et de compenser notamment les limites techniques de la MLST, 15 marqueurs génétiques ont été sélectionnés comme marqueurs potentiellement indicateurs de l’hôte, après analyse de plus de 800 génomes de C. jejuni. Par la suite, la capacité de la MLST, la CGF40 et des 15 marqueurs à identifier l’origine des campylobactérioses a été étudiée. Ainsi, les 15 marqueurs se sont révélés être particulièrement performants pour l’attribution de sources des campylobactérioses, suivis ensuite par la MLST, tandis que la CGF40 est apparue comme étant peu adaptée. A partir des données MLST et des 15 marqueurs génétiques, une implication majoritaire des volailles et des bovins a été mis en évidence en France, tandis que les animaux de compagnie et l’environnement (comprenant eau et oiseaux sauvages) étaient faiblement impliqués. Ceci permet ainsi de renforcer les efforts de recherche relatifs aux moyens de lutte contre Campylobacter menés dans ces réservoirs. Ce travail a également permis de mettre en évidence de potentielles spécificités nationales dans la dynamique de transmission de C. jejuni à l’Homme. / Campylobacter is the causal agent of the main bacterial foodborne gastroenteritis in Europe. Since Campylobacter is frequently found in animal reservoirs, sources of human infection and transmission routes are various. However, to decrease the human burden of campylobacteriosis, it is essential to quantify the relative importance of the several reservoirs in human infections. For this purpose, we assessed the contamination of chicken, cattle and pets by Campylobacter spp., and further characterized C. jejuni isolates using MLST (Multilocus Sequence Typing) and CGF (Comparative Genomic Fingerprinting) in comparison with French clinical isolates. Then, in order to identify the most likely origin of campylobacteriosis cases in France and overcome MLST limitations in source attribution, about 800 C. jejuni genomes were analyzed which resulted in the identification of 15 genes as promising host segregating markers for source attribution. Subsequently, we assessed the ability of MLST, CGF40 and the 15 host-segregating markers to identify the most likely origin of campylobacteriosis. The 15 host-segregating markers were the most powerful in source attribution, followed by MLST, while CGF40 appeared to be not suitable for source attribution in our study. Based on MLST and the 15 markers, assignments of clinical cases emphasize the significant implication of chicken and ruminant in human infection by Campylobacter, while pets and the environment (including water and wild birds) were slightly involved, reinforcing the interest to focus control strategies on livestock. Finally this work highlights potential national variations in the transmission dynamics of C. jejuni to human.

Submitted by Adriana Martinez (amartinez@unoeste.br) on 2018-02-07T17:46:54Z No. of bitstreams: 2 ADILSON OLIVEIRA.pdf: 313073 bytes, checksum: 760378e31125b9946d2bbf47c1aeafdb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-07T17:46:54Z (GMT). No. of bitstreams: 2 ADILSON OLIVEIRA.pdf: 313073 bytes, checksum: 760378e31125b9946d2bbf47c1aeafdb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-28 / Toxocariasis is an important zoonosis of worldwide distribution. The main way of transmission of the disease to human is the ingestion of soil containing embryonated eggs of Toxocara spp., the etiological agent. Studies have indicated the ingestion of raw or undercooked meat of chickens as another way of transmission. Besides, free-range chickens have been considered a good sentinel for the contamination of soil by Toxocara spp. eggs. The aim of this study was to evaluate the presence of anti-Toxocara antibodies in naturally infected broiler chickens (n=189) slaughtered in an abattoir located in Paraná, southern Brazil. The chickens were reared in a semi-intensive system by small familial farmers (n=7). An ELISA test was performed to detect the presence of anti-Toxocara IgY after serum adsorption with Ascaridia galli extract. An overall seroprevalence of 67.7% (128/189; 95% confidence interval [CI] = 61.1-74.4) was observed. The frequency of positive animals by farm ranged from 29.6% to 100%. The optical density and reactivity index indicated the possible chronicity of infection of the evaluated chickens. Associations between the presence of antibodies and the area where chickens were reared (p = 0.382) or the population density of dogs on the farm (p = 0.785) were not observed. This study shows a high frequency of Toxocara spp. infection in broiler chickens reared in semi-intensive systems and provides significant evidence that chickens are good indicator of environmental contamination by larva migrans agents. Further studies are necessary to assess the risk factors associated with poultry infection and the likelihood of toxocariasis transmission to humans via the ingestion of free-range chicken meat. / Toxocaríase é uma importante zoonose, com ampla distribuição mundial. A principal via de transmissão da doença para humanos se deve à ingestão acidental de ovos de Toxocara spp. presentes NO solo. Estudos têm descrito a infecção de seres humanos pelo consumo de carne crua ou mal cozida de frango. Os frangos criados em sistema semi-intensivo têm sido também considerados como sentinelas para a contaminação de solo por ovos de Toxocara spp. Com a finalidade de avaliar a presença de anticorpos anti-Toxocara em frangos de corte, foram colhidas 189 amostras de sangue de frangos em um abatedouro no Norte do Paraná. Os frangos foram criados em sistema colonial/caipira (sistema semi-intensivo), em pequenas propriedades rurais (n=7) pertencentes a produtores vinculados a uma associação de pequenos produtores. Os testes sorológicos foram realizados pela técnica de ELISA indireto, utilizando-se antígenos excretórios-secretórios (TES) de Toxocara canis para detecção de anticorpos IgY (IgG), com preadsorção do soro com antígenos de Ascaridia galli, para redução de reações cruzadas. Como resultado, foi obtida uma prevalência de 67,7% (128/189; IC 95%= 61,1-74,4), com uma variação de 29.6% a 100% entre as propriedades. Não foi observada correlação entre a positividade dos animais quando comparada a área (p= 0,382) e a densidade populacional de cães por propriedade (p= 0,785). Os resultados demonstraram alta frequência de anticorpos anti-Toxocara em frangos de corte criados em sistema semi-intensivo, indicando que essas aves podem ser indicadores de contaminação ambiental por agentes de larva migrans. Outros estudos são necessários para avaliar os riscos associados à transmissão de toxocaríase aos humanos pelo consumo da carne de frangos criados no sistema colonial/caipira.

Submitted by Michele Mologni (mologni@unoeste.br) on 2018-11-23T17:01:02Z No. of bitstreams: 1 Aline da Silveira Batista.pdf: 165848 bytes, checksum: c187bcd430f8b370d46748116a9de117 (MD5) / Made available in DSpace on 2018-11-23T17:01:02Z (GMT). No. of bitstreams: 1 Aline da Silveira Batista.pdf: 165848 bytes, checksum: c187bcd430f8b370d46748116a9de117 (MD5) Previous issue date: 2018-08-16 / The objective of this study was to compare the efficiency of different techniques to recover Toxocara spp. eggs from artificially and naturally contaminated soil samples. In the first stage, soil samples (n= 12 samples of 1g) were artificially contaminated with 100 eggs of T. canis. Three techniques were used: 1) centrifugal-sedimentation after soil filtration in a series of four sieves, using distilled water (300, 212, 90, and 63 μm); 2) centrifugal-flotation with zinc sulfate (d= 1.35 g/cm3) after sieving; and, 3) centrifugal-flotation with zinc sulfate without sieving. The recovery of eggs using technique 1 was significantly superior to the other techniques, with 78.25%, 16.33%, and 10.92% positivity, respectively. In the second stage, soil samples from 15 public squares/parks were evaluated over a period of 6 months, comparing the more efficient techniques in stage 1 (techniques 1 and 2). The recovery of eggs by technique 1 was more efficient. In the three out of the 6 months evaluated, there was a significant difference in the mean number of eggs recovered, using the technique of centrifugal-sedimentation with sieving. The technique is low cost, easy to implement, and does not require solutions which present environmental risks for its execution. / O objetivo do estudo foi comparar a eficiência de três técnicas de recuperação de ovos de Toxocara spp., a partir de amostras de solo artificialmente e naturalmente contaminadas. Na primeira etapa, amostras de solo (n= 12 amostras de 1g) foram contaminadas com 100 ovos de T. canis. Foram utilizadas três técnicas: 1) centrifugo-sedimentação após filtragem do solo em série de quatro tamises (300, 212, 90 e 63 μm); 2) centrifugo-flutuação com sulfato de zinco (d = 1.35 g/cm3) após tamisação; e, 3) centrifugo-flutuação com sulfato de zinco sem tamisação. A recuperação de ovos pela técnica 1 foi significativamente superior às demais, com 78,25%; 16,33% e 10,92% de positividade, respectivamente. Em uma segunda etapa, foram avaliadas amostras de solo de 15 praças e parques públicos de Presidente Prudente, São Paulo, durante um período de 6 meses, com comparação das técnicas 1 e 2. A recuperação de ovos pela técnica 1 mostrou ser mais eficiente. Em três meses avaliados, houve diferença significativa na média dos ovos recuperados. A técnica de tamisação centrifugo-sedimentação mostrou maior eficiência na recuperação de ovos de Toxocara spp. em relação as outras técnicas. A técnica é de baixo custo, fácil execução e não requer soluções com riscos ambientais para sua execução.

No description available.