Ecological study and risk mapping of leishmaniasis in an endemic area of Brazil based on a geographical information systems approach

Visceral leishmaniasis is a vector-borne disease highly influenced by eco-epidemiological factors. Geographical information systems (GIS) have proved to be a suitable approach for the analysis of environmental components that affect the spatial distribution of diseases. Exploiting this methodology, a model was developed for the mapping of the distribution and incidence of canine leishmaniasis in an endemic area of Brazil. Local variations were observed with respect to infection incidence and distribution of serological titers, i.e. high titers were noted close to areas with preserved vegetation, while low titers were more frequent in areas where people kept chickens. Based on these results, we conclude that the environment plays an important role in generating relatively protected areas within larger endemic regions, but that it can also contribute to the creation of hotspots with clusters of comparatively high serological titers indicating a high level of transmission compared with neighbouring area

Haementeria lutzi Pinto, 1920 (Hirudinea: Glossiphoniidae) as a putative Vector of Trypanosoma evansi (Kinetoplastida: Trypanosomatidae) in the Pantanal Matogrossense (MS, Brazil)

Made available in DSpace on 2015-08-19T13:49:29Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) alba_silva_etal_IOC_2013.pdf: 1563648 bytes, checksum: 1d97530604f5a8efe8342fb514778815 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica de Proteínas e Peptídeos. Rio de Janeiro, RJ, Brasil.In the present study, it was shown under experimental conditions that Trypanosoma evansi could be mechanically transmitted to Rattus norvegicus by leeches (Haementeria lutzi). Additionally, we also described some aspects related to the behavior of the Trypanosoma evansi in the leeches after an infective blood feeding, as follows: a) 10 minutes after the parasites were ingested; they promptly progressed to the coelomic cavity. b) Approximately, from 10 to 30 minutes inside the gut, rounded and dividing forms together with stumpy and slender trypomastigotes showed a random dispersion. c) 24 hours after, the trypanosomes also invaded both, the salivary glands as well as the proboscis cells. Our results suggest that leeches of the species Haementeria lutzi could have some role as a probable alternative vector of Trypanosoma evansi at wetlands in Brazil

Lutzomyia longipalpis Breeding—A Probable Breeding Substrate for Lutzomyia longipalpis in Nature

Submitted by Sandra Infurna ([email protected]) on 2019-02-10T17:34:07Z No. of bitstreams: 1 joaocarlos_carreira_etal_IOC_2018.pdf: 6680805 bytes, checksum: 3fa333cfd80231a5f2b379d509e67427 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-02-10T17:42:03Z (GMT) No. of bitstreams: 1 joaocarlos_carreira_etal_IOC_2018.pdf: 6680805 bytes, checksum: 3fa333cfd80231a5f2b379d509e67427 (MD5)Made available in DSpace on 2019-02-10T17:42:03Z (GMT). No. of bitstreams: 1 joaocarlos_carreira_etal_IOC_2018.pdf: 6680805 bytes, checksum: 3fa333cfd80231a5f2b379d509e67427 (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.The identifying of the preferred breeding sites of sand fly immature forms is quite important to the understanding of the vector’s biology and the development of more effective control strategies for leishmaniasis. In the present study, it was analyzed experimentally; the potential of dog feces of serving as breeding substrate to Lutzomyia longipalpis . Two situations were tested: 1) the life cycle of the insects from larvae to adults, 2) the whole cycle from adults to adults. Our results demonstrated for the first time that: 1) L. long ipalpis can be easily bred in dog feces, suggesting that it could represent a potential raising substrate to immature forms for this species; 2) L. longipalpis larvae are able to make galleries on a substrate, literally burying themselves in this to function also as a shelter; 3) from the previous information that dogs infected with Ancylostoma caninum can present dodecanoic acid in their feces, we suggested that this substrate may be particularly more attractive to L. longipalpis females seen that this molecule is the same component of their oviposition pheromone, which is produced by the accessory glands and secreted onto the eggs; 4) after the copulation the males may landing on the substrate and continued beating the wings intermittently until the death in a similar behavior also noticed in other situations associated to kairomones response or pheromone production. Therefore, we suggested that it is very likely that dog excrements could serve as an important breeding substrate for L. longipalpis in endemic areas of visceral leishmaniasis in the New World

Leishmaniasis in domestic dogs: epidemiological aspects

Submitted by Sandra Infurna ([email protected]) on 2019-12-10T18:26:21Z No. of bitstreams: 1 AlbaValeriaSilva_JoaoCarlosCarreira_etal_IOC_2005.pdf: 52008 bytes, checksum: d08b60c92b64e8c7f46909c4504b3e2f (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-12-10T18:34:01Z (GMT) No. of bitstreams: 1 AlbaValeriaSilva_JoaoCarlosCarreira_etal_IOC_2005.pdf: 52008 bytes, checksum: d08b60c92b64e8c7f46909c4504b3e2f (MD5)Made available in DSpace on 2019-12-10T18:34:01Z (GMT). No. of bitstreams: 1 AlbaValeriaSilva_JoaoCarlosCarreira_etal_IOC_2005.pdf: 52008 bytes, checksum: d08b60c92b64e8c7f46909c4504b3e2f (MD5) Previous issue date: 2005Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Em Barra de Guaratiba, área endêmica de leishmaniose visceral americana (LVA) no Rio de Janeiro, Brasil, as campanhas de controle não têm sido capazes de reduzir a infecção canina. Este fato nos levou a aprofundar o estudo do cão como reservatório da Leishmania chagasi em ambiente periurbano, através de acompanhamento clínico e sorológico usando as técnicas de IFA e WB. O reconhecimento dos peptideos de 29 e 32kDa por soro de cães comprovadamente infectados por L. chagasi foi observado. Além disso, somente soros de cães sintomáticos reconheceram o antígeno de 68,5kDa, podendo esse peptídeo ser recomendado como parâmetro para eliminação dos cães em área endêmica. A técnica de WB provou ser mais sensível que IFA, desde que as frações peptídicas de 29 e 32kDa foram reconhecidas por soro de cães soronegativos para LVA, até 8 meses antes da soroconversão pelo IFA. A proximidade da mata foi fator relevante para aumentar o risco de infecção por L. chagasi nos cães, possivelmente devido à presença de reservatórios silvestres.In Barra de Guaratiba, an endemic area for American visceral leishmaniasis (AVL) in Rio de Janeiro, Brazil, control campaigns were unable to reduce canine infection rates. This difficulty prompted an in-depth study of dogs as a reservoir for Leishmania chagasiin the peri-urban environment through clinical and serological follow-up using the immunofluorescence and Western blot techniques. Recognition of 29kDa and 32kDa peptides by sera from dogs with proven L. chagasi infection was observed. Furthermore, only sera from symptomatic dogs recognized the 68.5kDa antigen, so the latter should be considered a parameter for culling dogs from endemic areas. The WB technique proved to be more sensitive than IFA, since the 29 and 32kDa peptide fractions were even recognized by sera from AVL seronegative dogs up to 8 months before IFA seroconversion. Proximity to wooded areas was an important risk factor for L. chagasi infection in dogs, possibly due to the presence of wild reservoirs