Dengue

With an estimated global incidence of 390 million infections per year, dengue is the most widely distributed arthropod-borne virus (arbovirus) to infect humans. Billions of people live at risk of infection, and recent changes in global climate and human living patterns have allowed dengue incidence to increase at a faster rate than that of any other communicable disease except SARS-CoV-2. Rapidly urbanizing societies, increasing movement of people, and geographical expansion of the key mosquito vectors, Aedes aegypti and Aedes albopictus, mean that dengue incidence is projected to continue rising for much of the remainder of this century. With the majority of clinically apparent infections giving rise to mild disease, overall mortality is less than 0.1%, but the associated social and economic burden is high, with low- and middle-income countries being disproportionately affected. In its severest form, dengue can be rapidly life-threatening, when development of capillary leakage leads to hypovolaemic shock and organ dysfunction. Children, pregnant women, older people, and individuals with comorbidities are at risk of severe disease, as are those with pre-existing sub-neutralizing levels of dengue IgG as a result of prior infection with alternative viral serotypes. Despite significant recent investment in dengue research, effective antivirals and adjunctive therapies remain elusive, so clinical management relies on meticulous clinical monitoring and judicious fluid replacement. Various strategies for dengue prevention are under development, including infection of mosquitoes with the dengue-limiting bacteria Wolbachia, and identification of several potential vaccine candidates. Disappointingly, however, suitability of the first licensed dengue vaccine, Dengvaxia, has been shown to be limited to baseline seropositive individuals only. This chapter describes dengue’s epidemiology, transmission characteristics, and pathogenesis, as well as the typical clinical presentation and optimal management of cases. It concludes by discussing current and future strategies for vector control and disease prevention.