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Volume 32, Number 4—April 2026
Research
Dengue Incidence, Seroprevalence, and Expansion Factors from Active Surveillance, Brazil, 2016–2021
, Morgan A. Marks, Elizabeth M. Anderson, Alejandra Esteves-Jaramillo, Germán Áñez, José A. Sousa Moreira, and Fernanda Castro Boulos
Table 2
Dengue serostatus at baseline for participants enrolled in large phase 3 efficacy trial of a dengue vaccine trial, Brazil, 2016–2021*
| Characteristic | Seropositive, no. (%) | Seronegative, no. (%) |
|---|---|---|
| Participants with a known baseline dengue serostatus |
8,050 (49.6) |
7,555 (46.5) |
| Sex | ||
| F | 4,493 (51.2) | 3,910 (44.6) |
| M |
3,557 (47.7) |
3,645 (48.8) |
| Age at enrollment, y | ||
| 2–6 | 870 (17.3) | 4,061 (81.0) |
| 7–17 | 3,120 (60.6) | 1,860 (36.1) |
| 18–59 |
4,060 (66.9) |
1,634 (26.9) |
| Race | ||
| Pardo† | 5,685 (51.4) | 4,942 (44.7) |
| White | 1,693 (44.4) | 1,991 (52.2) |
| Black | 514 (48.4) | 492 (46.3) |
| Asian | 133 (50.6) | 115 (43.7) |
| Indigenous or other |
25 (56.8) |
15 (34.1) |
| Geographic region | ||
| North | 2,531 (51.1) | 2,154 (43.5) |
| Northeast | 2,591 (57.1) | 1,766 (38.9) |
| Center-West | 1,489 (52.9) | 1,243 (44.2) |
| South | 28 (5.7) | 449 (91.8) |
| Southeast | 1,411 (41.0) | 1,943 (56.5) |
*Participants were from the DEN-03-IB trial of a live attenuated tetravalent dengue vaccine, Butantan-DV. Prior exposure (i.e., dengue seropositive) is defined as having a baseline 60% virus reduction neutralization test titer to any of the 4 dengue virus serotypes above the assay limit of detection. †Multiracial Brazilian.
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.