Volume 32, Number 4—April 2026
Research
Dengue Incidence, Seroprevalence, and Expansion Factors from Active Surveillance, Brazil, 2016–2021
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.
Page created: February 27, 2026
Page updated: April 15, 2026
Page reviewed: April 15, 2026
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.