Dengue (Pediatric)

Dengue is an acute viral infection caused by the dengue virus (a flavivirus) transmitted by Aedes mosquitoes, leading to fever, myalgia, rash, and, in severe cases, plasma leakage, hemorrhage, and shock in children.

Definition

Epidemiology

Endemic in tropical and subtropical regions worldwide
Peak incidence during rainy seasons when mosquito breeding is high
Children are more susceptible to severe forms due to secondary infections
Incidence is increasing globally due to urbanization and climate change
All four dengue virus serotypes (DEN-1 to DEN-4) circulate in endemic areas

Etiology

Dengue virus (DENV) transmitted by Aedes aegypti and Aedes albopictus mosquitoes
Primary infection provides lifelong immunity to the same serotype but not to others
Secondary infection with a different serotype increases risk of severe dengue (antibody-dependent enhancement)
Host factors: young age, comorbidities, malnutrition can influence severity
Environmental factors: stagnant water, high mosquito density, urban areas

Pathophysiology

Virus infects dendritic cells, monocytes, and hepatocytes leading to systemic viremia
Activation of immune system results in cytokine storm and increased vascular permeability
Plasma leakage into pleural and peritoneal cavities can cause hypovolemic shock
Thrombocytopenia occurs due to bone marrow suppression and peripheral destruction
Coagulopathy can develop in severe cases, causing bleeding manifestations
Secondary infection triggers antibody-dependent enhancement, increasing disease severity