Dengue
More Dengue information from the Health Protection Surveillance Centre
Advice for travellers
Time: Precautions during daylight
Avoid risky areas: i.e. near water
Use mosquito repellents:
Dress safely: wear long sleeves, long trousers, socks and closed shoes.
Use air conditioning and screens
- Severe 'flu like viral infection, all age groups.
- Transmitted by Aedes mosquite bite
- Bites risk : daytime, tropics & subtropics.
- Recently Comoro Islands.
Clinical
- Incubation period 3-14 days (usually 4-7).
- Abrupt onset fever, chills, headache, arthralgia.
- Back pain ("breakbone fever") and prostration ( exhaustion).
- Rash in 50% - faint macular, erythematous with discrete pale spared areas.
- Capillary test confirms capillary fragility.
- Lasts up to 10 day.
- May progress to haemorrhagic fever (beware petechial rash fragile gums) and shock (may be fatal).
- No vaccine available
- Prevention - avoid mosquito bites (advice).
Capillary test
Specificity >85%, sensitivity 30%
Apply BP cuff above venous pressure for 5 minutes. Positive = >2 petechiae distal to the cuff.
Labs
- Leucopenia with a relative lymphocytosis.
- Thrombocytopenia.
- Abnormla LFTs.
- Clotting abnormalities if haemorrhagic / shock developing.
- Confirm Dx with IgM antibodies against flavivirus.
Management
- Supportive.
Differential Dx
- Malaria - ALL need malaria screens.
- Rickettsial infections.
- Enteric fever.
- Acute HIV seroconversion.
Links
- Health Protection Surveillance Site
- WHO information on Dengue Fever
