Morning Report: Dengue Fever

Thanks to Dr. Abram for today’s Morning Report!

Dengue Fever

(“Breakbone Fever”)

Virus: Flavivirus – 4 related viruses (DENV 1-4). Other flavivirus include St. Louis Encephalitis, West Nile Virus, Yellow Fever.

Vector: Mosquito – Aedes aegypti most common in western hemisphere, Aedes albopictus

Prevention: mosquito prevention – local repellents, avoiding stagnant water

Location: worldwide, very common in Puerto Rico, Latin America, U.S. Virgin Islands. Outbreaks in Hawaii and Texas increasing.

Incubation: 5-7 days. Duration: 5-7 days.

Physical Exam: High fever, relative bradycardia, scleral injection, pharyngeal injection, macular rash.

Symptoms: retrobulbar pain, headache, myalgias, arthralgias, bone pain, weakness, nausea, anorexia

Lab values: leucopenia, thrombocytopenia, hyponatremia, elevated AST/ALT, normal ESR

Critical time starts at defervescence lasts 24-48 hours:

Dengue Hemorrhagic Fever: Less than 10% of all dengue cases. Lethal in 50% without treatment, 5% with treatment. Thrombocytopenia and vascular permeability. Pleural effusions, ascities, third-spacing can all occur from IVF. Severe vomiting, abdominal pain, dyspnea, hypotension, shock à seizure/coma/death. May include severe hemorrhagic complications (hematochezia, melena, hematemesis, menorrhagia) if prolonged shock.

Rare complications: encephalitis, pancreatitis, myocarditis, hepatitis.

Diagnosis: PCR <4 days. Viral antigen (IgM anti-DENV) from blood via ELISA. Former CSF-IgM tests may be false positive from other flaviviridae.

Treatment: Supportive, antipyrexis, hydration. If Dengue Hemorrhagic Fever, consider isolation and intensive care unit. Avoid ASA and NSAID for anticoagulant properties.

References:

CDC website Dengue Fever. www.cdc.gov/dengue Accessed 8/8/2015.

Bausch, Daniel. Dengue Fever. Viral Hemorrhagic Fevers. Goldman-Cecil Medicine, 381, 2247-2256

Tenagne Haile-Mariam and Larissa May. Viral Illnesses. Rosen’s Emergency Medicine, Chapter 130, 1718-1741