Certifying the interruption of Chagas disease transmission by native vectors : cui bono?

Certifying the absence of Chagas disease transmission by native vectors lacks scientific grounds and weakens long-term control-surveillance systems to the detriment of people living under risk conditions. Instead, a regular "certification of good practice" (including vector control-surveillance, case detection/patient care and blood safety) could help achieve sustained disease control

Does Triatoma brasiliensis occupy the same environmental niche space as Triatoma melanica?

Submitted by Nuzia Santos ([email protected]) on 2016-02-19T16:12:55Z No. of bitstreams: 1 Does Triatoma brasiliensis occupy the same.pdf: 568419 bytes, checksum: 8ebd865012b7ba92c6be897286f9868e (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-02-19T16:19:20Z (GMT) No. of bitstreams: 1 Does Triatoma brasiliensis occupy the same.pdf: 568419 bytes, checksum: 8ebd865012b7ba92c6be897286f9868e (MD5)Made available in DSpace on 2016-02-19T16:19:20Z (GMT). No. of bitstreams: 1 Does Triatoma brasiliensis occupy the same.pdf: 568419 bytes, checksum: 8ebd865012b7ba92c6be897286f9868e (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais, Brazil.Secretaria de Saúde do Estado do Ceará. Fortaleza, CE, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas. Belo Horizonte, Minas Gerais, Brazil.IMBIV-CONICET. Córdoba, Argentina.Background: Triatomines (Hemiptera, Reduviidae) are vectors of Trypanosoma cruzi, the causative agent of Chagas disease, one of the most important vector-borne diseases in Latin America. This study compares the environmental niche spaces of Triatoma brasiliensis and Triatoma melanica using ecological niche modelling and reports findings on DNA barcoding and wing geometric morphometrics as tools for the identification of these species. Methods: We compared the geographic distribution of the species using generalized linear models fitted to elevation and current data on land surface temperature, vegetation cover and rainfall recorded by earth observation satellites for northeastern Brazil. Additionally, we evaluated nucleotide sequence data from the barcode region of the mitochondrial cytochrome c oxidase subunit I (CO1) and wing geometric morphometrics as taxonomic identification tools for T. brasiliensis and T. melanica. Results: The ecological niche models show that the environmental spaces currently occupied by T. brasiliensis and T. melanica are similar although not equivalent, and associated with the caatinga ecosystem. The CO1 sequence analyses based on pair wise genetic distance matrix calculated using Kimura 2-Parameter (K2P) evolutionary model, clearly separate the two species, supporting the barcoding gap. Wing size and shape analyses based on seven landmarks of 72 field specimens confirmed consistent differences between T. brasiliensis and T. melanica. Conclusion: Our results suggest that the separation of the two species should be attributed to a factor that does not include the current environmental conditions. However, as the caatinga is a biome that has existed in the area for at least the last 18,000 years, past conditions might have had an influence in the speciation process. The DNA Barcoding approach may be extended to these members of the subfamily Triatominae

The exotic palm Roystonea oleracea (Jacq.) O. F. cook as a rural biotype for Rhodnius neglectus Lent, 1954, in Caçu, state of Goiás

IntroductionRhodnius neglectus is a triatomine that colonizes different palm species. In this study, we aimed to describe the presence of this triatomine bug in the royal palms (Roystonea oleracea) in a rural region of the State of Goiás.MethodsPalm infestation was investigated by dissecting the palms or by using live-bait traps.ResultsTwo palm trees were infested by R. neglectusnegative for Trypanosoma cruzi, the etiological agent for Chagas disease. In the study area, R. neglectus is frequently found in households.ConclusionsThe adaptation of this species to palm trees introduced in Brazil for landscaping purposes poses another challenge for controlling the vectors of Chagas disease

Different profiles and epidemiological scenarios: Past, present and future

The multiplicity of epidemiological scenarios shown by Chagas Disease, derived from multiple transmission routes of the aetiological agent, occurring on multiple geo-ecobiosocial settings determines the complexity of the disease and reveal the difficulties for its control. From the first description of the link between the parasite, the vector and its domestic habitat and the disease that Carlos Chagas made in 1909, the epidemiological scenarios of the American Trypanosomiasis has shown a dynamic increasing complexity. These scenarios changed with time and geography because of new understandings of the disease from multiple studies, because of policies change at the national and international levels and because human movements brought the parasite and vectors to new geographies. Paradigms that seemed solid at a time were broken down, and we learnt about the global dispersion of Trypanosoma cruzi infection, the multiplicity of transmission routes, that the infection can be cured, and that triatomines are not only a health threat in Latin America. We consider the multiple epidemiological scenarios through the different T. cruzi transmission routes, with or without the participation of a Triatominae vector. We then consider the scenario of regions with vectors without the parasite, to finish with the consideration of future prospects.Fil: Gorla, David Eladio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Xiao Nong, Zhou. Chinese Centre For Tropical Diseases Research; ChinaFil: Diotaiuti, Liléia. Fundación Oswaldo Cruz; BrasilFil: Khoa, Pham Thi. Science Services Of Insect Joint Stock Company; VietnamFil: Waleckx, Etienne. Université de Montpellier. Unité Mixte de Recherche, Interactions In The Neglected; Francia. Universidad Autónoma de Yucatán; MéxicoFil: de Cássia Moreira de Souza, Rita. Centro de Pesquisas Rene Rachou. Fiocruz Mg; Brasil. Fundación Oswaldo Cruz; BrasilFil: Qin, Liu. Shanghai Jiao Tong University. National Institute Of Parasitic Diseases, One Health Center; ChinaFil: Lam, Truong Xuan. Institute Of Ecology And Biological Resources; VietnamFil: Freilij, Hector León. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Departamento de Medicina; Argentin