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| Author(s): |
Antonio Charlys da Costa
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Medicina Tropical de São Paulo (IMT) |
| Defense date: | 2017-05-31 |
| Examining board members: |
Ester Cerdeira Sabino;
Celso Francisco Hernandes Granato;
José Eduardo Levi;
João Renato Rebello Pinho;
Dercy José de Sá Filho
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| Advisor: | Ester Cerdeira Sabino |
| Abstract | |
Dengue virus is responsible for one of the most important vector-borne diseases in the world, causing about 390 million infections annually in more than 100 countries. It is estimated that more than 3.51 billion people (40% of the world\'s population) are living in regions at risk. The geographic distribution of dengue types has increased dramatically in recent decades, driven by the expansion of its major vector species, Aedes aegypti, human population growth, travel, international trade and increasing urbanization in the tropics and subtropics. Objectives: To carry out the molecular characterization of the complete genome of the DENGUE virus; Evaluate evolutionary trends that may be occurring in the Brazilian epidemic, comparing our findings with those in the literature; Methods: Samples of donors and blood recipients collected between February 15 and June 15, 2012 in blood banks and hospitals in the cities of Recife, PE and Rio de Janeiro, RJ. A viral genome of 90 samples was performed and phylodynamics and mathematical models were analyzed to estimate epidemiological data. Results: Phylogenetic analyzes indicated that the outbreak was caused by dengue virus 4 genotype II, although two genotype I isolates were also detected for the first time in Rio de Janeiro. Evolutionary analysis and modeling estimates are congruent, indicating a reproductive number above 1 between January and June, with at least two-thirds of the infections being unnoticed. Model analysis suggests that viral transmission began in early January, consistent with multiple introductions, most likely from the northern states of Brazil, and with a simultaneous increase in air travel within the country to Rio de Janeiro. Discussion: The national surveillance system reported 213,000 dengue cases in RJ and PE in 2012, on the other hand, we inferred at least a 3.4 times higher number of dengue infections, according to previous estimates based on serological data. Temperature based models and entomological surveys have shown that the Amazon region of Brazil is highly suitable for DENV transmission throughout the year. The most parsimonious explanation for the absence of reported cases in urban centers studied by 2012. Rio de Janeiro consistently receives new DENV lineages showing that it is unlikely that the transmission chains within this state will be sustained at various seasons of the year and therefore will require reintroduction of origin. Conclusion: The combination of genetic and epidemiological data from blood donors may be useful in anticipating the epidemic spread of arboviruses (AU) | |
| FAPESP's process: | 12/03417-7 - Complete genomes for dengue virus: viral genetic diversity among seropositive first-time blood donors and recipients in two blood centres in Brazil |
| Grantee: | Antonio Charlys da Costa |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |