Sonographic findings of healthy volunteers infected with dengue virus

Purpose. Sonography has historically been used in developing countries to help diagnose dengue infection during epidemics of dengue hemorrhagic fever in endemic areas and to predict the clinical course. In this article, we describe the sonographic findings in subjects infected with attenuated, monovalent strains of dengue virus. Methods. As part of a major research protocol to validate challenge strains of dengue virus for use in vaccines, 12 subjects were infected with 1 of 4 strains of dengue virus, and 3 subjects received placebo. The challenge was followed by an observation period. During this time, they were imaged regardless of the development of symptoms. Results. Seven of 12 subjects infected with dengue virus showed sonographic evidence of subclinical plasma leakage, including perihepatic and perisplenic ascites, pericardial effusion, and gallbladder wall thickening. None of the 3 placebo recipients developed effusions. Conclusion. Sonographic evidence of fluid collection was seen in over half of subjects infected with dengue virus who did not show any evidence of dengue hemorrhagic fever. These findings shed light on possible mechanisms of plasma leakage and its role in the pathogenesis of dengue fever and dengue hemorrhagic fever.