Real-time genomic surveillance during the 2021 re-emergence of the yellow fever virus in Rio Grande do Sul State, Brazil

Abstract The yellow fever virus (YFV) re-emergence in Rio Grande do Sul, Brazil, raised big concerns and led the state to declare a Public Health Emergency of State Importance. Here, we generated near-complete genomes from the ongoing outbreak in Southern Brazil, aiming to better understand the phylogenetic aspects and also spatio-temporal dynamics of the virus. Our findings highlight the path and dispersion in Rio Grande do Sul and that YFV was reintroduced from Sao Paulo to the Rio Grande do Sul state through Parana and Santa Catarina states, at the end of 2020.