At least 75% of dengue infections are asymptomatic. If a patient does have symptoms, they develop three to fourteen days after being bitten by an infected mosquito. The first phase of dengue (the febrile) is two to seven days of fever, headache, pain behind the eyes, myalgia and bone pain, rash, a low white blood cell (WBC) count, and evidence of bleeding, such as petechiae or nose/gum bleeding. Mild illness can be treated with rest, plenty of fluids, and acetaminophen. Treatment with aspirin is contraindicated because bleeding may worsen.
Severe dengue (critical stage) is no longer called dengue hemorrhagic fever or dengue shock syndrome. It follows symptomatic dengue after a day or two of defervescence and can be deadly if appropriate treatment is not received. Symptoms of severe dengue occur because capillaries become permeable and plasma leaks into the chest or abdomen. Abdominal pain, vomiting, thrombocytopenia, breathing difficulties, and possibly severe bleeding manifestations can be seen in some patients. Only about 1% of patients die and they are usually children; the others convalescence over four to seven days.
There is no specific treatment, but vaccines are in development.
