Dengue is a viral disease transmitted by mosquitoes (especially Aedes aegypti) and is widely distributed throughout the tropics and subtropics. Dengue classically presents with high fever, headache, body aches, exanthem, and generalized lymphadenopathy. Symptoms usually subside within one week. Some cases progress to the more severe dengue hemorrhagic fever (DHF) with thrombocytopenia, spontaneous bleeding, and potentially shock (dengue shock syndrome). Treatment is supportive. A vaccination is available for use in children, living in endemic areas, with confirmed prior dengue virus infection.
- Distribution: tropical regions; worldwide, particularly Asia (e.g., Thailand)
- Most common viral disease affecting tourists in tropical regions
- ∼ 400 million infections per year worldwide
Epidemiological data refers to the US, unless otherwise specified.
- Transmission route 
|Clinical featues of Dengue fever|
|Dengue fever||Dengue without warning signs || |
|Dengue with warning signs |
|Severe dengue (Formally called dengue hemorrhagic fever or DHF) || |
|Dengue shock syndrome (DSS)|| |
If symptoms appear more than 2 weeks after returning from a dengue-endemic region, it is very unlikely that dengue is the cause.
Severe dengue is more frequent in individuals who experience a repeat infection with a second serotype, especially serotype 2.
- ↑ AST
- Hct significantly increased or decreased in DHF (due to plasma leakage)
Confirmation of diagnosis 
Acute phase (≤ 7 days after symptom onset)
- Serologic tests: MAC-ELISA to detect IgM
- Molecular Tests (NAAT) to detect viral RNA
- NS1 antigen test: detection of the Dengue NS1 antigen (Dengue non-structural protein 1) via ELISA 
- Tissue tests (IHC)
Convalescent phase (i.e., > 7 days after symptom onset)
Chikungunya fever 
- Epidemiology: mainly occurs in the tropical and subtropical regions
- Clinical features
- Treatment: supportive
Complication: chronic arthritis
- Most common and severe complication
- May last for months to years and lead to long-term disability
- Prognosis: Most individuals fully recover within a week.
The differential diagnoses listed here are not exhaustive.
- Avoid exposure, use of mosquito repellent (see also → )
- A tetravalent attenuated live vaccine (CYD-TDV)