Transmission of Plamodium vivax in an urban area of the Brasilian Amazon: spatial and temporal analysis.

Author(s)

Lais Camoese Salla

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2019-06-19

Examining board members

Marcelo Urbano Ferreira; Paulo Eduardo Martins Ribolla; Maria Anice Mureb Sallum; Marcia Aparecida Sperança

• Advisor: Marcelo Urbano Ferreira

Abstract

After 36 years of decline in the malaria incidence, in 2017 and 2018 Brazil presented 51% increase in the number of diagnosed cases compared to the previous year, with transmission virtually restricted to the Amazon region. The focal nature of malaria transmission in Brazil suggests that elimination efforts will require careful prioritization of a few residual malaria pockets. In this work, we use parasites population genetic approaches to study the transmission dynamics of residual malaria in the urban area of Mâncio Lima. This site is located in Juruá Valley, a region in the western Amazon that accounts for 20% of the cases of malaria in Brazil. Microsatellite DNA markers were used to characterize 178 P. vivax samples collected over 14 months in Mâncio Lima, collected for analysis of spatial and temporal distribution, the parasite population structure and levels of genetic diversity and multiplicity infections, aiming to identify temporal and spatial patterns of parasites strain circulation in the host population. The results revealed high rates of genetic diversity, multiplicity of infection and linkage disequilibrium, indicating low recombination between unrelated clones. The sample grouping indicated the constant introduction of different parasites in the city and the ability of a single and numerous group to propagate through space and time. We suggest that the high prevalence of malaria in the city of Mâncio Lima is supported by a constant introduction of parasites in a place with high receptivity and transmission capacity of the disease. (AU)

• FAPESP's process: 17/02351-6 - Transmission dynamics of Plasmodium vivax in an urban area of the Brazilian Amazon: spatial and temporal analysis
• Grantee: Lais Camoese Salla
• Support Opportunities: Scholarships in Brazil - Master