Dengue Fever With Warning Signs

This randomized, double-blind, three parallel-group, multicenter, phase 3b trial evaluates the safety and immunogenicity of Butantan-DV. The study compares two primary immunization regimens (Butantan-DV/Butantan-DV vs. Butantan-DV/Placebo) across both the 2-11 and 12-17 age cohorts. It also evaluates the manufacturing facility transition for the Butantan-DV dengue vaccine, by comparing the open-label arm WuXi Biologics (Butantan-DV group) to both double-blinded Butantan-DV/Butantan-DV and Butantan-DV/Placebo arms, in adolescents aged 12 to 17.

Dengue fever, a viral infection transmitted by Aedes mosquitoes, is a major health issue in tropical and subtropical regions. Around 20-30% of symptomatic patients developed Dengue Hemorrhagic Fever (DHF), which leads to impaired hemostasis, subsequently increasing the risk of bleeding. The hemostatic abnormalities associated with dengue infection included vascular permeability, platelet dysfunction, and coagulation defects. Therefore, Individuals with underlying bleeding disorders are at increased risk of bleeding. Dengue infection in patients with hemophilia was reported, including six of 843 patients in the cohort with underlying hemophilia: five with hemophilia A and one with hemophilia B. Replacement therapy was more commonly used in patients with bleeding disorders and dengue than in patients with other febrile illnesses. All of them had bleeding during dengue infection. The mortality rate was high at 16%. Despite the importance of this issue, there is a lack of registries or data-collection systems to determine the bleeding complications, the requirement for replacement therapy, and the outcome of dengue infection in congenital bleeding disorders (CBDs). Therefore, this research aims to establish a registry of dengue infections among individuals with CBDs. The study is a multicenter, retrospective study from 1 January 2015 to 31 December 2025 and a prospective cohort study involving hospitals that treat individuals with CBDs and dengue. The registry format will be provided using REDCap system.

This 3-year prospective observational study aims to identify clinical and laboratory risk factors associated with hospitalization in patients with confirmed dengue virus infection. It also seeks to analyze real-world transfusion practices and their outcomes. The study will be conducted in a second-level hospital in northern Mexico and will follow patients from emergency department entry to clinical resolution or hospital discharge.