MARCOS AMAKU
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, Faculdade de Medicina - Docente
LIM/01 - Laboratório de Informática Médica, Hospital das Clínicas, Faculdade de Medicina
LIM/01 - Laboratório de Informática Médica, Hospital das Clínicas, Faculdade de Medicina
3 resultados
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- Effects of migration rates and vaccination on the spread of yellow fever in Latin American communities(2023) SIMON, Sabrina; AMAKU, Marcos; MASSAD, EduardoObjective. To assess how relevant the flow of people between communities is, compared to vaccination and type of vector, on the spread and potential outbreaks of yellow fever in a disease-free host community.Methods. Using a SEIRV-SEI model for humans and vectors, we applied numerical simulations to the scenar-ios: (1) migration from an endemic community to a disease-free host community, comparing the performance of Haemagogus janthinomys and Aedes aegypti as vectors; (2) migration through a transit community located on a migratory route, where the disease is endemic, to a disease-free one; and (3) effects of different vaccina-tion rates in the host community, considering the vaccination of migrants upon arrival.Results. Results show no remarkable differences between scenarios 1 and 2. The type of vector and vacci-nation coverage in the host community are more relevant for the occurrence of outbreaks than migration rates, with H. janthinomys being more effective than A. aegypti.Conclusions. With vaccination being more determinant for a potential outbreak than migration rates, vac-cinating migrants on arrival may be one of the most effective measures against yellow fever. Furthermore, H. janthinomys is a more competent vector than A. aegypti at similar densities, but the presence of A. aegypti is a warning to maintain vaccination above recommended levels.
- Toxoplasma gondii and Neospora caninum antibody seroprevalence and risk factors among dogs treated at Public Veterinary Hospitals in São Paulo, Brazil(2023) SANTOS, Elidia Zotelli dos; SOARES, Herbert Souza; SANTOS, Stephanie Rodrigues dos; MORAES FILHO, Jonas; PENA, Hilda Fatima de Jesus; AMAKU, Marcos; GENNARI, Solange MariaDogs can be infected by Toxoplasma gondii and Neospora caninum, for which they function, respectively, as intermediate, and definitive hosts. In the present study seroprevalence against T. gondii and N. caninum antibodies, were determined by indirect fluorescent antibody test (cut off of 16 and 50, respectively), in dogs that were treated at public veterinary hospitals in the metropolitan region of Sao Paulo and risk factors were identified. Out of the 1,194 samples 125 (10.5%; 95% CI: 8.8-12.3%) were positive for T. gondii and 9 (0.75%, 95% CI: 0.34-1.4%) for N. caninum. For T. gondii, statistical differences were observed between the proportions of positive dogs and different zones of the municipality (p = 0.025), and age (p = 0.02), higher among older dogs. The keepers were invited to answer an epidemiological questionnaire to analyze risk factors, and 471 (39.4%) agreed to be interviewed, and among their dogs 65 (13.8%) were T. gondii seropositive. Age group above 8 years (OR = 3.63; 95% CI: 1.08-12.23) was a risk factor and having a defined breed (OR = 0.49; 95% CI: 0.25-0.96) was a protective factor for T. gondii infection. Because of the low number of dogs positive for N. caninum, risk factors for this coccidium were not determined.
- hybridModels: An R Package for the Stochastic Simulation of Disease Spreading in Dynamic Networks(2020) MARQUES, Fernando S.; GRISI-FILHO, Jose H. H.; AMAKU, Marcos; SILVA, Jean C. R.; ALMEIDA, Erivania C.; SILVA JUNIOR, Jose L.Disease spreading simulations are traditionally performed using coupled differential equations. However, in the setting of metapopulations, most of the solutions provided by this method do not account for the dynamic topography of subpopulations. Conversely, the alternative approach of individual-based modeling (IBM) may add computational cost and complexity. Hybrid models allow for the study of disease spreading because they combine both aforementioned approaches by separating them across different scales: a local scale that addresses subpopulation dynamics using coupled differential equations and a global scale that addresses the contact between these subpopulations using IBM. We present a simple way of simulating the spread of disease in dynamic networks using the high-level statistical computational language R and the hybridModels package. We built four examples using disease spread models at the local scale in several different networks: an animal movement network; a three-node network, whose model solution using a stochastic simulation algorithm is compared with the ordinary differential equations approach; the commuting of individuals between patches, which we compare with the permanent migration of individuals; and the commuting of individuals within the metropolitan area of Sao Paulo.