Do humans comprise a significant source of infection for the sand fly vectors of visceral leishmaniasis in north Brazil?

• Processo: 11/51404-9
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Data de Início da vigência: 01 de dezembro de 2011
• Data de Término da vigência: 31 de julho de 2014
• Área do conhecimento: Ciências da Saúde - Medicina - Anatomia Patológica e Patologia Clínica
• Acordo de Cooperação: Universidade Hebraica de Jerusalém
• Pesquisador responsável: Marcia Dalastra Laurenti
• Beneficiário: Marcia Dalastra Laurenti
• Pesquisador Responsável no exterior: Alon Warburg
• Instituição Parceira no exterior: Hebrew University of Jerusalem, Israel
• Instituição Sede: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brasil
• Assunto(s): Zoonoses Leishmaniose visceral Transmissão de doença infecciosa Reservatórios de doenças Período de transmissibilidade Reação em cadeia da polimerase em tempo real Imunidade celular Imunidade humoral
• Palavra(s)-Chave do Pesquisador: Cellular Immunity | Human Visceral Leishmaniasis | Humoral Immunity | Reservoir Potencial | Transmissibility | Zoonosis

Resumo

In Brazil transmission of visceral leishmaniasis (VL) is mostly zoonotic with dogs serving as reservoir hosts. However culling of infected dogs has failed to reduce transmission suggesting the possible contribution of humans as parasite reservoirs for infecting sand flies. Competent reservoir hosts must be abundant and long lived. The infection should be long enough and non-pathogenic to permit survival of the infected/infective hosts. Sufficient parasite loads should be present in the skin and/or blood to promote high infection rates in biting vectors. The current project will evaluate whether humans living in a VL endemic area, fulfill these criteria. An epidemiological survey in a peri-urban focus Bujarú near Belem will characterize different immunological/clinical profiles (skin test, immuno-fluorescent assay) with respect to VL and verify the physical presence of parasites in the blood by real-time PCR, parasite culture and artificial xenodiagnosis. The data will be used to assess which sub-population contributes most to infection of sand flies. Data will be compared with similar data derived from a project on going in Ethiopia where the disease is primarily anthroponotic. Results will shed light on the possible role of humans as reservoir hosts of L. infantum in Brazil. (AU)