Dengue viral infections and shock syndromes: An overview

Abstract

Dengue viral infections are caused by one of four single stranded RNA viruses of the family Flaviviridae. They can occur virtually throughout the tropics and are transmitted by their mosquito vector, Aedes aegypti. Dengue, the most common arboviral disease in the world, has become more prevalent now than ever before and its prevalence is expected to increase. The risk for severe disease is determined by a complex interplay of epidemiological, virus and host factors. The clinical syndromes caused by dengue viral infections occur in an iceberg fashion along a severity continuum. Most cases are asymptomatic and a much smaller proportion present with severe forms of the disease-dengue hemorrhagic fever/dengue shock syndrome-that are characterized by sudden increase in vascular permeability and consequent shock. The traditional WHO classification and grading of dengue fever, dengue hemorrhagic fever and dengue shock syndrome are described along with a discussion of the timing and methods of laboratory diagnosis. Management is predominantly supportive. In patients with severe shock, treatment strategies are double pronged and include methods to judiciously resolve shock and control bleeding while simultaneously preventing fluid overload and its complications, including the need for assisted ventilation. These considerations are especially relevant in resource limited tropical countries where dengue viral infections are amongst the leading causes of childhood hospitalization, morbidity and death.

Keywords

Dengue - dengue hemorrhagic fever - dengue shock syndrome - shock - dengue immunopathogenesis - dengue diagnosis - management of shock - prevention of fluid overload