Page 42 - ICGES Libro de Resúmenes MAC

Resumen de Conferencias Internacionales (CI)

YELLOW FEVER EPIDEMIC IN BRAZIL
CI­07 Pedro Fernando da Costa Vasconcelos

Department of Arbovirology and Hemorrhagic Fever, Instituto Evandro Chagas,
Ananindeua, Brazil and Department of Pathology , Universidade do estado do
Pará, Belém, Brazil

Yellow Fever is an infectious disease caused by the yellow fever virus (YFV),
Flavivirus genus of the Flaviviridae family, which is endemic in Brazil and many
countries in South America, and periodically has caused limited outbreaks in
Amazonian and non­Amazon regions. Between December 2016 and June 2018,
the largest Yellow Fever (YF) outbreak in the last eight decades occurred in
Brazil. More than 2,153 human cases and 2,276 epizootics were confirmed.
Molecular epidemiological studies were conducted to improve understanding of
the outbreak. Viral isolates were sequenced and used for genetic
characterization, phylogenetic analysis and temporal reconstructions of the YFV.
New YFV nearly complete genomes were sequenced with specific mutations,
which were related to the recent outbreak. Phylogenetic analysis and
reconstructions indicated a Brazilian Amazon enzootic origin for the 2016­2018
YFV outbreak, suggesting that the YFV strains from this epidemic have specific
amino acid mutations possible due to adaptive mechanisms along a given time­
frame. In this presentation we reported the large scale of 2016­2018 Yellow
Fever outbreak in Brazil, including the occurrence of epizootics and sporadic
human cases in Brazil, and demonstrating an unprecedented distribution in the
Brazilian territory. Phylogenetic and temporal reconstructions identified distinct
YFV lineage associated to distinct Brazilian geographic regions, as well as
suggested the enzootic origin of the YFV associated to the current outbreak in
Amazon rain forest for at least 30 years.

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