Dengue Fever Prevention
Neither vaccine nor drugs for preventing infection are available. The bite of one infected mosquito can result in infection. The risk of being bitten is highest during the early morning, several hours after daybreak, and in the late afternoon before sunset. However, mosquitoes may feed at any time during the day. Aedes mosquitoes typically live indoors and are often found in dark, cool places such as in closets, under beds, behind curtains, and in bathrooms. Travelers should be advised to use insecticides to get rid of mosquitoes in these areas and to select accommodations with well-screened windows or air conditioning when possible. Additionally, travelers should take measures to avoid being bitten by mosquitoes. Long-term travelers and expatriates can take extra precautions to reduce mosquito-breeding sites around their accommodations by emptying and cleaning or covering any standing water (such as in water storage tanks and flowerpot trays).
Because dengue fever is caused by a virus, there is no specific medicine or antibiotic to treat it. For typical dengue, the treatment is purely concerned with relief of the symptoms. Rest and fluid intake for adequate hydration is important. Aspirin and nonsteroidal anti-inflammatory drugs should only be taken under a doctor’s supervision because of the possibility of worsening bleeding complications. Acetaminophen (Tylenol) and codeine may be given for severe headache and for joint and muscle pain (myalgia).
What is the prognosis for typical dengue fever?
Typical dengue is fatal in less than 1% of cases. The acute phase of the illness with fever and myalgias lasts about one to two weeks. Convalescence is accompanied by a feeling of weakness (asthenia), and full recovery often takes several weeks.
What is dengue hemorrhagic fever?
Dengue hemorrhagic fever (DHF) is a specific syndrome that tends to affect children under 10 years of age. It causes abdominal pain, hemorrhage(bleeding), and circulatory collapse (shock). DHF is also called Philippine, Thai, or Southeast Asian hemorrhagic fever and dengue shock syndrome.
DHF starts abruptly with high continuous fever and headache. There are respiratory and intestinal symptoms with sore throat, cough, nausea,vomiting, and abdominal pain. Shock occurs two to six days after the start of symptoms with sudden collapse, cool, clammy extremities (the trunk is often warm), weak pulse, and blueness around the mouth (circumoral cyanosis).
In DHF, there is bleeding with easy bruising, blood spots in the skin (petechiae), spitting up blood (hematemesis), blood in the stool (melena), bleeding gums, and nosebleeds (epistaxis). Pneumonia is common, and inflammation of the heart (myocarditis) may be present.
Patients with DHF must be monitored closely for the first few days since shock may occur or recur precipitously (dengue shock syndrome). Cyanotic(bluish) patients are given oxygen. Vascular collapse (shock) requires immediate fluid replacement. Blood transfusions may be needed to control bleeding.
The mortality (death) rate with DHF is significant. With proper treatment, the World Health Organization estimates a 2.5% mortality rate. However, without proper treatment, the mortality rate rises to 20%. Most deaths occur in children. Infants under a year of age are especially at risk of dying from DHF.