Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPJESUS, Jaqueline Goes deDUTRA, Karina RochaSALES, Flavia Cristina da SilvaCLARO, Ingra MoralesTERZIAN, Ana CarolinaCANDIDO, Darlan da SilvaHILL, Sarah C.THEZE, JulienTORRES, CelesteD'AGOSTINI, Tatiana LangFELIX, Alvina ClaraREIS, Andreia F. NegriALCANTAR, Luiz Carlos JuniorABREU, Andre L. deCRODA, Julio H. R.OLIVEIRA, Wanderson K. deFILIPIS, Ana Maria Bispo deCAMIS, Maria do Carmo Rodrigues dos SantosROMANO, Camila MaltaLOMAN, Nick J.PYBUS, Oliver G.SABINO, Ester CerdeiraNOGUEIRA, Mauricio L.FARIA, Nuno Rodrigues2020-08-202020-08-202020MEMORIAS DO INSTITUTO OSWALDO CRUZ, v.115, article ID e190423, 6p, 20200074-0276https://observatorio.fm.usp.br/handle/OPI/36872BACKGROUND Despite efforts to mitigate the impact of dengue virus (DENV) epidemics, the virus remains a public health problem in tropical and subtropical regions around the world. Most DENV cases in the Americas between January and July 2019 were reported in Brazil. Sao Paulo State in the southeast of Brazil has reported nearly half of all DENV infections in the country. OBJECTIVES To understand the origin and dynamics of the 2019 DENV outbreak. METHODS Here using portable nanopore sequencing we generated20 new DENV genome sequences from viremic patients with suspected dengue infection residing in two of the most-affected municipalities of Sao Paulo State, Araraquara and Sao Jose do Rio Preto. We conducted a comprehensive phylogenetic analysis with 1,630 global DENV strains to better understand the evolutionary history of the DENV lineages that currently circulate in the region. FINDINGS The new outbreak strains were classified as DENV2 genotype III (American/Asian genotype). Our analysis shows that the 2019 outbreak is the result of a novel DENV lineage that was recently introduced to Brazil from the Caribbean region. Dating phylogeographic analysis suggests that DENV2-III BR-4 was introduced to Brazil in or around early 2014, possibly from the Caribbean region. MAIN CONCLUSIONS Our study describes the early detection of a newly introduced and rapidly-expanding DENV2 virus lineage in Brazil.engopenAccessdengue 2outbreakgenomic surveillancelineage replacementBrazilzika viruscirculationarticleCopyright FUNDACO OSWALDO CRUZ10.1590/0074-02760190423ParasitologyTropical Medicine1678-8060