PLoS Neglected Tropical Diseases (Dec 2023)

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

  • Rosângela 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

DOI
https://doi.org/10.1371/journal.pntd.0011863
Journal volume & issue
Vol. 17, no. 12
p. e0011863

Abstract

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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 those aged 30-44 and 45-59 years (16.1% and 15.6%, respectively), compared to younger (12.4% and 11.7% in Conclusions/significanceUnlike observations in other settings, the initial spread of CHIKV in this large urban center was limited and focal in certain areas, leaving a high proportion of the population susceptible to further outbreaks. Additional investigations are needed to elucidate the factors driving CHIKV spread dynamics, including understanding differences with respect to dengue and Zika viruses, in order to guide prevention and control strategies for coping with future outbreaks.