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

Authors :
Anjos RO
Portilho MM
Jacob-Nascimento LC
Carvalho CX
Moreira PSS
Sacramento GA
Nery Junior NRR
de Oliveira D
Cruz JS
Cardoso CW
Argibay HD
Plante KS
Plante JA
Weaver SC
Kitron UD
Reis MG
Ko AI
Costa F
Ribeiro GS
Source :
PLoS neglected tropical diseases [PLoS Negl Trop Dis] 2023 Dec 27; Vol. 17 (12), pp. e0011863. Date of Electronic Publication: 2023 Dec 27 (Print Publication: 2023).
Publication Year :
2023

Abstract

Background: The 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.<br />Methodology/principal Findings: To 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 <15 and 15-29 years, respectively) or older (10.3% in ≥60 years) age groups, but the differences were not statistically significant. The cumulative seroprevalence was similar between men (14.7%) and women (12.5%). Yet, among those aged 15-29 years, men were more often infected than women (18.1% vs. 7.4%, respectively, P = 0.01), while for those aged 30-44, a non-significant opposite trend was observed (9.3% vs. 19.0%, respectively, P = 0.12). Three spatial clusters of cases were detected in the study site and an increased likelihood of CHIKV infection was detected among participants who resided with someone with CHIKV IgG antibodies.<br />Conclusions/significance: Unlike 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.<br />Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: A.I.K is an expert panel member for Reckitt Global Hygiene Institute and a scientific advisory committee member for Merck-related arboviral research but outside the scope of the manuscript. S.C.W. holds patents for alphavirus vaccine development. Other authors declare no conflict of interest<br /> (Copyright: © 2023 Anjos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Details

Language :
English
ISSN :
1935-2735
Volume :
17
Issue :
12
Database :
MEDLINE
Journal :
PLoS neglected tropical diseases
Publication Type :
Academic Journal
Accession number :
38150470
Full Text :
https://doi.org/10.1371/journal.pntd.0011863