Epidemiological and genomic investigation of chikungunya virus in Rio de Janeiro state, Brazil, between 2015 and 2018

• Published in: PLoS neglected tropical diseases Vol. 17; no. 9; p. e0011536
• Main Authors: Moreira, Filipe Romero Rebello, Menezes, Mariane Talon de, Salgado-Benvindo, Clarisse, Whittaker, Charles, Cox, Victoria, Chandradeva, Nilani, Paula, Hury Hellen Souza de, Martins, André Frederico, Chagas, Raphael Rangel das, Brasil, Rodrigo Decembrino Vargas, Cândido, Darlan da Silva, Herlinger, Alice Laschuk, Ribeiro, Marisa de Oliveira, Arruda, Monica Barcellos, Alvarez, Patricia, Tôrres, Marcelo Calado de Paula, Dorigatti, Ilaria, Brady, Oliver, Voloch, Carolina Moreira, Tanuri, Amilcar, Iani, Felipe, Souza, William Marciel de, Cardozo, Sergian Vianna, Faria, Nuno Rodrigues, Aguiar, Renato Santana
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.09.2023; Public Library of Science (PLoS)
• Subjects: Analysis; Aquatic insects; Biology and life sciences; Brazil - epidemiology; Chikungunya Fever; Chikungunya virus; Chikungunya virus - genetics; Computer and Information Sciences; Diagnosis; Disease Outbreaks; Earth Sciences; Ecology and Environmental Sciences; Epidemiology; Estimates; Genetic aspects; Genomes; Genomics; Humans; Humidity; Infections; Investigations; Medicine and Health Sciences; Mosquitoes; Outbreaks; People and places; Phylogeny; Positive selection; Proteins; Replication; Reproduction; RNA; Seasonal variations; Structural proteins; Vector-borne diseases; Viral replication; Zika virus; Brazil; Asia; Rio de Janeiro Brazil; Indian Ocean
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0011536

Since 2014, Brazil has experienced an unprecedented epidemic caused by chikungunya virus (CHIKV), with several waves of East-Central-South-African (ECSA) lineage transmission reported across the country. In 2018, Rio de Janeiro state, the third most populous state in Brazil, reported 41% of all chikungunya cases in the country. Here we use evolutionary and epidemiological analysis to estimate the timescale of CHIKV-ECSA-American lineage and its epidemiological patterns in Rio de Janeiro. We show that the CHIKV-ECSA outbreak in Rio de Janeiro derived from two distinct clades introduced from the Northeast region in mid-2015 (clade RJ1, n = 63/67 genomes from Rio de Janeiro) and mid-2017 (clade RJ2, n = 4/67). We detected evidence for positive selection in non-structural proteins linked with viral replication in the RJ1 clade (clade-defining: nsP4-A481D) and the RJ2 clade (nsP1-D531G). Finally, we estimate the CHIKV-ECSA's basic reproduction number (R0) to be between 1.2 to 1.6 and show that its instantaneous reproduction number (Rt) displays a strong seasonal pattern with peaks in transmission coinciding with periods of high Aedes aegypti transmission potential. Our results highlight the need for continued genomic and epidemiological surveillance of CHIKV in Brazil, particularly during periods of high ecological suitability, and show that selective pressures underline the emergence and evolution of the large urban CHIKV-ECSA outbreak in Rio de Janeiro.