Dynamics of chikungunya virus transmission in the first year after its introduction in Brazil: A cohort study in an urban community

by Ros ângela O. Anjos, Moyra M. Portilho, Leile Camila Jacob-Nascimento, Caroline X. Carvalho, Patrícia S. S. Moreira, Gielson A. Sacramento, Nivison R. R. Nery Junior, Daiana de Oliveira, Jaqueline S. Cruz, Cristiane W. Cardoso, Hernan D. Argibay, Kenneth S. Plante, Jessica A. Plante, Scott C. Weaver, Uriel D. Kitron, Mitermayer G. Reis, Albert I. Ko, Federico Costa, Guilherme S. Ribeiro BackgroundThe first chikungunya virus (CHIKV) outbreaks during the modern scientific era were identified in the Americas in 2013, reaching high attack rates in Caribbean countries. However, few cohort studies have been performed to characterize the initial dynamics of CHIKV transmission in the New World. Methodology/Principal findingsTo describe the dynamics of CHIKV transmission shortly after its introduction in Brazil, we performed semi-annual serosurveys in a long-term community-based cohort of 652 participants aged ≥5 years in Salvador, Brazil, between Feb-Apr/2014 and Nov/2016-Feb/2017. CHIKV infections were detected using an IgG ELISA. Cumulative seroprevalence and seroincidence were estimated and spatial aggregation of cases was investigated. The first CHIKV infections were identified between Feb-Apr/2015 and Aug-Nov/2015 (incidence: 10.7%) and continued to be detected at low incidence in subsequent surveys (1.7% from Aug-Nov/2015 to Mar-May/2016 and 1.2% from Mar-May/2016 to Nov/206-Feb/2017). The cumulative seroprevalence in the last survey reached 13.3%. It was higher among th...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research