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| Author(s): |
Claudia Araujo Scinachi
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR) |
| Defense date: | 2022-02-17 |
| Examining board members: |
Adriano Pinter dos Santos;
Marcelo Bahia Labruna;
Luis Filipe Mucci;
Matias Pablo Juan Szabo
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| Advisor: | Adriano Pinter dos Santos |
| Abstract | |
Brazilian Spotted Fever (BSF) is a vector-borne zoonosis whose agent is the bacteria Rickettsia rickettsii. In the São Paulo Metropolitan Region (SPMR), the vector responsible for the disease transmission is the tick Amblyomma aureolatum, which depends on environmental characteristics of the Atlantic Forest biome to survive. Domestic dogs are the main hosts of the adult stage of the tick in areas of urban matrix close to fragmented forest, and participate in the disease cycle by carrying infected ticks from the forest to the anthropic environment. Furthermore, they can amplify the bacteria and contribute to increase the number of infected ticks in nature. In order to elucidate the gaps in relation to BSF in the SPMR, this study tested the hypothesis that dogs could act as amplifying hosts of R. rickettsii for A. aureolatum ticks after a second contact with the agent. The results showed that the dogs could not generate new infected tick strains despite an immune response with increased antibody titers. This study also determined, through spatial modeling, which areas are more likely to present cases of BSF, taking into account the necessary conditions for A. aureolatum occurrence and the ecological aspects that facilitate the interaction of the vector with its hosts in the environment. The environmental variables of altitude and temperature showed to have the greatest influence on vector distribution, while the increase in edge perimeter and decrease in forest cover favored the occurrence of BSF. This study brings new data on the ecoepidemiology of Brazilian Spotted Fever in the State of São Paulo and draws attention to the importance of domestic dogs in the disease cycle in the Metropolitan Region of the state. Prevention actions focused on dog population are extremely important to reduce disease incidence and improve the human population\'s health conditions. (AU) | |
| FAPESP's process: | 17/05255-8 - Evaluation of domestic dogs as competent amplifier hosts to the bacterium Rickettsia rickettsii to Amblyomma aureolatum ticks and predictive spacial ecological modeling for occurrence of Brazilian Spotted Fever in the state of São Paulo |
| Grantee: | Claudia Araujo Scinachi |
| Support Opportunities: | Scholarships in Brazil - Doctorate |