Dengue Fever

Dengue fever is an infectious disease carried by mosquitoes and caused by any of four related dengue viruses, DEN-1, DEN-2, DEN-3, and DEN-4. This disease used to be called "break-bone" fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking, hence the name.

Dengue fever is found mostly during and shortly after the rainy season in tropical and subtropical areas of Africa, Southeast Asia, India, Central and South America, and Australia.

Worldwide, more than 100 million cases of dengue infection occur each year. The dengue virus infections are transmitted via bite of an infected Aedes mosquito. Mosquitoes become infected when they bite infected humans, and later transmit infection to other people they bite. Two main species of mosquito, Aedes aegypti and Aedes albopictus, have been responsible for all cases of dengue transmitted in this country. Dengue is not contagious from person to person.

Symptoms and Diagnosis

Symptoms of typical uncomplicated (classic) dengue usually start with fever within 5 to 6 days after being bitten by an infected mosquito. They include

• High fever, up to 105 degrees Fahrenheit
• Severe headache
• Retro-orbital (behind the eye) pain
• Severe joint and muscle pain
• Nausea and vomiting
• Rash

The rash may appear over most of the body 3 to 4 days after the fever begins. Some people may get a second rash later in the disease.

Complications

Dengue infection may cause dengue hemorrhagic fever or dengue shock syndrome, which are more severe than the classic dengue.

Symptoms of dengue hemorrhagic fever include all of the symptoms of classic dengue plus

• Marked damage to blood and lymph vessels
• Bleeding from the nose, gums, or under the skin, causing purplish bruises

This form of dengue disease can cause death.

Symptoms of dengue shock syndrome--the most severe form of dengue disease--include all of the symptoms of classic dengue and dengue hemorrhagic fever, plus

• Fluids leaking outside of blood vessels
• Massive bleeding
• Shock (very low blood pressure)

This form of the disease usually occurs in children (sometimes adults) experiencing their second dengue infection. It is sometimes fatal, especially in children and young adults.

Treatment

There is no specific treatment for classic dengue fever, and most people will recover completely within 2 weeks. To help with recovery, health care experts recommend

• Getting plenty of bed rest
• Drinking lots of fluids
• Taking medicine to reduce fever

The Centers for Disease Control and Prevention (CDC) advises people with dengue fever not to take aspirin. Acetaminophen or other over-the-counter pain-reducing medicines are safe for most people.

For severe dengue symptoms, including shock and coma, early and aggressive emergency treatment with fluid and electrolyte replacement can be lifesaving.

References:

Centers for Disease Control and Prevention, USA.
National Institute of Allergy and Infectious Diseases, USA.