Dengue%20(pediatric) Signs and Symptoms

• According to the World Health Organization (WHO), the global incidence of dengue cases increased by 15-fold over the last 2 decades, with global mortality count increasing from 960 in the year 2000 to 4032 in 2015
• Dengue is now endemic in >100 countries in the WHO regions of Africa, the Americas, the Eastern Mediterranean, South-East Asia and the Western Pacific, with the global incidence rate of symptomatic cases coming predominantly from Asia (~70%)

• Dengue infection is caused by the Dengue virus, which belongs to the family Flaviviridae
• There are 4 serotypes (DENV-1, DENV-2, DENV-3, DENV-4) 
  • Each serotype provides specific lifetime protective immunity against reinfection of the same serotype, but only temporary (within 2-3 months of the primary infection) and partial protection against the other serotypes
• The fifth serotype, DENV-5, is a new variant that follows the sylvatic cycle (transmission of dengue virus to non-human primates) while the other 4 serotypes are transmitted between humans

 Pathophysiology 

• It is transmitted to humans through the bites of infected Aedes mosquitoes
  • Primarily transmitted by female Aedes aegypti, a tropical and subtropical species
  • Other outbreaks were secondary to A albopictus, A polynesiensis, A scutellaris
  • Humans are the main host of the virus
• After 4-10 days of incubation period, illness begins immediately

Phases of Dengue Infection

Febrile Phase

• Patient suddenly develops high-grade fever that commonly lasts for 2-7 days and is associated with facial flushing, skin redness, generalized arthralgia, myalgia, headache, anorexia, nausea, vomiting
  • May also be accompanied by sore throat, injected pharynx, conjunctival injection, mucosal/gastrointestinal bleeding
  • Likelihood of dengue infection is increased by a positive torniquet test and progressive decrease in total white blood cell (WBC) count
  • Progression to critical phase should be recognized promptly by monitoring for warning signs and other clinical parameters

Critical Phase

• Occurs on days 3-7 of illness and usually lasts for 1-2 days
• Patient’s temperature lowers to ≤37.5-38^oC and may have increase in capillary permeability concurrent with increase in hematocrit level
• Patient may develop pleural effusion, ascites, shock, organ impairment, metabolic acidosis, disseminated intravascular coagulation which may lead to severe hemorrhage
  • Depends on the degree of plasma leakage and the volume of fluid therapy
• Other patient may proceed with this phase even without defervescence
  • Changes in the full blood count may be the only guide to determine the onset of plasma leakage

Recovery Phase

• 2-3 days after critical phase has been successfully surpassed
• Patients may present with respiratory distress due to massive pleural effusion and ascites if excessive intravenous (IV) fluids were given