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Volume 32, Number 4—April 2026

Research

Dengue Incidence, Seroprevalence, and Expansion Factors from Active Surveillance, Brazil, 2016–2021

Eliana Nogueira Castro de Barros, Manuela de Almeida Roediger, Maïna L’Azou JacksonComments to Author , Morgan A. Marks, Elizabeth M. Anderson, Alejandra Esteves-Jaramillo, Germán Áñez, José A. Sousa Moreira, and Fernanda Castro Boulos
Author affiliation: Instituto Butantan, São Paulo, Brazil (E.N.C. Barros, M.A. Roediger, J.A.S. Moreira, F.C. Boulos); MSD (UK) Limited, London, UK (M. L'Azou Jackson); Merck & Co., Inc., Rahway, New Jersey, USA (M.A. Marks, E.M. Anderson, A. Esteves-Jaramillo, G. Áñez)

Main Article

Figure 1

VCD and laboratory-confirmed chikungunya incidence by demographic characteristics, Brazil, 2016–2021. Incidence per 100 person-years of VCD is shown regardless of serotype (A), VCD by DENV serotypes DENV-1 and DENV-2 (B), and laboratory-confirmed chikungunya (C) among participants in the placebo arm of the DEN-03-IB trial of a live attenuated tetravalent dengue vaccine, Butantan-DV, by demographic characteristic (age at event, sex, and baseline dengue serostatus). Points represent incidence estimates and error bars represent 95% CIs. Dashed lines represent the overall incidence per 100 person-years and shaded areas around the dashed lines represent 95% CIs for the overall incidence estimates. Prior exposure (i.e., dengue seropositive) is defined as having a baseline 60% virus reduction neutralization test titer to any of the 4 DENV serotypes above the assay limit of detection. +, positive; –, negative; DENV, dengue virus; VCD, virologically confirmed dengue.

Figure 1. VCD and laboratory-confirmed chikungunya incidence by demographic characteristics, Brazil, 2016–2021. Incidence per 100 person-years of VCD is shown regardless of serotype (A), VCD by DENV serotypes DENV-1 and DENV-2 (B), and laboratory-confirmed chikungunya (C) among participants in the placebo arm of the DEN-03-IB trial of a live attenuated tetravalent dengue vaccine, Butantan-DV, by demographic characteristic (age at event, sex, and baseline dengue serostatus). Points represent incidence estimates and error bars represent 95% CIs. Dashed lines represent the overall incidence per 100 person-years and shaded areas around the dashed lines represent 95% CIs for the overall incidence estimates. Prior exposure (i.e., dengue seropositive) is defined as having a baseline 60% virus reduction neutralization test titer to any of the 4 DENV serotypes above the assay limit of detection. +, positive; –, negative; DENV, dengue virus; VCD, virologically confirmed dengue.

Main Article

1Preliminary results from this study were presented at the American Society for Tropical Medicine and Hygiene annual meeting; November 13–17, 2024, New Orleans, Louisiana, USA.

Page created: February 27, 2026
Page updated: April 06, 2026
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