Parasitose | EPFL Graph Search

Parasitose est un terme désignant l'ensemble maladies dues à des parasites, maladies parasitaires ou maladies parasitiques. La parasitologie est la science qui étudie les parasitoses chez l'Homme ou d'autres espèces (animaux, champignons, plantes). On peut placer les parasitoses en trois groupes selon leurs agents (parasites) : les protozoaires (parasites unicellulaires) ; les métazoaires (parasites pluricellulaires : vers parasites par exemple) ; les arthropodes servent souvent de vecteur permettant le transport du parasite. Certaines parasitoses affectent une zone particulière de l'organisme. L'oxyurose affecte les intestins. Chez l'homme ou l'animal, l'infestation peut se faire de différentes manières : par voie buccale ; par l'intermédiaire d'une piqûre d'insecte (par exemple le paludisme transmis par l'intermédiaire d'une piqûre d'anophèle, un moustique). Une seule piqure ou morsure (morsure de tique par exemple) peut introduire des parasites de plusieurs espèces différentes ; par voie pulmonaire ; par des œufs directement déposés dans une blessure. Kératite à Acanthamoeba Amœbose (dénomination de l'amibiase dans la nouvelle nomenclature) due à Entamoeba histolytica Anguillulose ou strongyloïdose Ascaridiose Babésiose Balantidiase Bilharziose ou schistosomiase Capillariose Diphyllobothriose (anciennement Bothriocéphalose) due à Diphyllobothrium latum Maladie de Chagas Clonorchiase (ou clonorchose ou distomatose à Clonorchis sinensis ou Douve de Chine) Cryptosporidiose Distomatose Dracunculose ou filariose également appelée ver de Guinée, ver d'Afrique ou filariose de Médine Échinococcose provoquée par un ver échinocoque Éléphantiasis ou filariose lymphatique Fasciolose, fascioliase ou distomatose hépatique provoquée par un trématode Fasciola hepatica Fièvre de Katayama Filariose Gale ou scabiose Giardiase ou lambliase Gnathostomiasis Hyménolépiose Isosporose Lambliase, giardiase ou giardiose Leishmaniose Malaria ou paludisme Métagonimiase Myiase provoqués par des larves de diptères parasites Onchocercose Oxyurose Paludisme ou malaria Pédiculose corporelle Pédiculose du cuir chevelu Scabiose, ou gale Schistosomiase ou bilharziose Strongyloïdose ou anguillulose Taeniasis (cause de cysticercose) Toxocarose Toxoplasmose Trichocéphalose ou trichiurose Trypanosomiase africaine ou maladie du sommeil Infestation (maladie) Bonsall, Michael (2010), Parasite Replication and the Evolutionary Epidemiology of Parasite Virulence.

A field-based modelling framework of the ecohydrology of schistosomiasis

Francisco Javier Perez Saez

Successful control of schistosomiasis, a water-borne parasitic disease, is challenged by the intricacy of the wormâs lifecycle, which depends on aquatic snail intermediate hosts, and involves environmental, ecologic, and socio-economic factors. Current strategies rely on deworming through mass drug administration which however do not protect against reinfection and the persistence of hotspots. It is recognized that multifaceted approaches will be necessary to reach elimination, whose development will require a renewed focus on the diseaseâs social-ecological drivers. Taking cue from the hydrological underpinning of these drivers, this Thesis aims at developing an ecohydrological approach to schistosomiasis with a view to identifying and exploiting the points in which its cycle can be broken. Schistosomiasis is a poverty-reinforcing disease affecting more than 150 million people in sub-Saharan Africa, being the parasitic disease causing the largest health burden after malaria. However, the impairing morbidity it causes has been undervalued in the past, qualifying it as a neglected tropical disease. Moreover, water resources development often exacerbate transmission, posing scientific and ethical challenges in addressing the ensuing trade-off between economic development and public health. The relevance of this Thesisâ work lies in furthering tools to offset this trade-off by unlocking the predictive appraisal of the social-ecological drivers of transmission. An integration of fieldwork applied in Burkina Faso (West Africa) and theoretical methods are employed to address this aim. This Thesis establishes the use of spatially explicit mathematical models of schistosomiasis at the national-scale, allowing to study the effect of human mobility and spatial heterogeneity of transmission parameters. Weekly ecological samplings of snail abundance and continuous environmental monitoring were preformed at three sites along the countryâs climatic gradient, leveraged through ecological modelling. A novel methodology for the large-scale prediction of river network ephemerality allowed for refined snail species distribution models, and the analysis of the diseaseâs geography in link with socio-economic covariates. Finally, surveys and participatory workshops shed light on local-scale water contact patterns. The obtained results substantiate the stance that hydrology is a first-order control of disease transmission. Stability analysis of the spatially explicit model generated additional insight into the impact of the expansion of suitable snail habitat due to water resources development, highlighting the interplay between local and country-wide effects driven by human mobility. Models of snail ecology revealed key hydrological drivers, and disputed density feedbacks. Uncovered phase shifts between permanent and ephemeral habitats were adequately reproduced at the national scale through model regionalization. Characterization and predictions of hydrological ephemerality improved the estimation of the snailsâ ecological range, mirroring the diseaseâs geography. Finally a national-scale association between ephemerality and disease risk was observed, possibly due to human-water contacts aggregation, as supported by preliminary results at village-level. The future incorporation of these ecohydrological findings into spatially explicit models of schistosomiasis is considered promising for optimizing control strategies and attaining disease elimination.

EPFL2018

A field-based modelling framework of the ecohydrology of schistosomiasis

Francisco Javier Perez Saez

EPFL2018