Dengue Fever

Key Features

• Travel or residence in an endemic area

• Transmitted by the Aedes mosquito (present in the southern United States)

• Failure to recognize and treat dengue hemorrhagic fever (DHF) may lead to dengue shock syndrome, which is defined by signs of circulatory failure and hypotension or shock, and has a high fatality rate (10%)

• Neurologic complications such as encephalitis, myositis, myelitis, Guillain-Barré syndrome, and mononeuropathies are reported in 5–10%

Clinical Findings

• Onset begins abruptly 4–7 days after transmission (range, 3–14 days) with

  • Fever, chills

  • Severe retro-orbital pain

  • Severe muscle and joint pain

  • Nausea, and vomiting

• Erythema of the face and torso may occur early

• Centrifugal maculopapular rash

  • Appears in half of the patients after 3–4 days

  • Described as "islands of white in a sea of red"

  • Can become petechial

  • Mild hemorrhagic signs (epistaxis, gingival bleeding, microscopic blood in stool or urine) may be noted

• The illness lasts 5–7 days, although rarely fever may reappear for several additional days

• Since there are four serotypes of dengue virus, multiple sequential infections can occur

Diagnosis

• Mild leukopenia and thrombocytopenia are common

• Liver function tests are usually normal

• Diagnosis is made by

  • Viral culture of plasma (50% sensitive up to the fifth day)

  • Presence of viral antigenemia (90% sensitive during the febrile phase of first infections)

  • Dengue PCR during the first 5 days

  • Presence of IgM-specific ELISA antibodies (70–80% sensitive at the sixth day)

  • Detection of a rise in type-specific antibody

• DHF is defined by significant thrombocytopenia (< 100,000 platelets/μL, bleeding, and a plasma leak syndrome [hemoconcentration = hematocrit > 20% higher than baseline], hypoalbuminemia, and pleural or peritoneal effusions)

Treatment

• Avoid high-risk areas and use conventional mosquito avoidance measures

• Oral rehydration and antipyretics should be given, avoiding nonsteroidal anti-inflammatory agents that affect platelet function

• Recovery is complete without sequelae

• The hemorrhagic syndrome requires prompt fluid therapy with plasma expanders and isotonic saline and close ICU monitoring