How to Diagnose Dengue

Dengue is an infection with the dengue arthropod-borne virus (arbovirus) of the genus Flavivirus. An infection only provides lifelong immunity for that particular serotype and four serotypes exist. Dengue is the most common arboviral infection and is considered a global health threat. It is transmitted to humans by mosquitoes of the Aedes genus, especially Aedes aegypti and Aedes albopictus in the United States. Here's how to diagnose dengue.

Instructions

• 1

  Observe the first symptoms of dengue. Facial flushing occurs in about half the cases and is a specific indicator of dengue. This is often accompanied by chills and a mottling of the skin. A fever usually begins on the third day and lasts five to seven days, sometimes reaching 104 degrees.

• 2

  Obtain blood cell counts. A low white blood cell count is a common finding at the end of the feverish phase of dengue and is often accompanied by a reduced lymphocyte count. Monitor the hematocrit and platelet count every day. A 20 percent rise in the hematocrit and a platelet count less than 100,000 are early warning signs of a progression to dengue hemorrhagic fever.

• 3

  Run a metabolic panel. A low sodium level is the most common electrolyte imbalance. Patients in shock will also have elevated blood urea nitrogen and metabolic acidosis.

• 4

  Confirm a diagnosis of dengue with serologic testing and polymerase chain reaction (PCR), if possible. This is important because the symptoms of dengue fever are nonspecific. The antibody titer of immunoglobulin M is most commonly measured with an enzyme-linked immunosorbent assay (ELISA.) A four fold increase in antibody titers is considered confirmatory.

• 5

  Use other tests to obtain antibody titers. These include a complement fixation, neutralization test, hemaggluination (HI) and an ELISA of immunoglobulin G.