Dengue Fever

What is dengue fever?

Dengue (pronounced den gee) is a viral disease transmitted by Aedes mosquitoes mainly in tropical and subtropical areas of the world, with the greatest risks occurring in:

  • South Pacific

  • South Central Asia 

  • Caribbean

  • Central and South America 

  • Africa

Dengue fever occurs most often in urban areas, but may be found in rural areas. Transmission of the virus, via Aedes mosquitoes, usually occurs during and shortly after the rainy season. These mosquitoes are most active during the day and are found near human dwellings, often indoors. According to the World Health Organization, the global incidence of dengue fever has grown dramatically in recent decades with about half of the world's population now at risk.  

What are the symptoms of dengue fever?

Dengue fever causes a severe flu-like illness and may be confused with other infectious diseases such as influenza or malaria. Symptoms may include:

  • Sudden onset, high fever

  • Severe headaches

  • Pain behind the eyes

  • Joint and muscle pain

  • Nausea

  • Vomiting

  • Swollen glands

  • Rash that appears three to four days after the onset of fever

The illness usually lasts three to seven days.

About 1 percent of people with dengue fever develop severe dengue, or dengue hemorrhagic fever. Symptoms appear as the fever begins to ease and may include persistent vomiting, rapid breathing, blood in vomit, and bleeding gums. A person with severe dengue may develop respiratory distress, severe bleeding, and damage to organs. The illness can progress to dengue shock syndrome, with very low blood pressure or shock. Immediate medical care should be sought to avoid complications, including death.

How can dengue fever be prevented?

Because there is not a vaccine for dengue fever, travelers should:

  • Avoid mosquito bites by using insect repellents on skin and clothing.

  • Stay in well screened or air conditioned areas.

When sleeping areas are not air conditioned or screened, the use of aerosol insecticides indoors and bednets are recommended.

How is dengue fever diagnosed?

Dengue fever infection is diagnosed by a special blood test to determine the presence of the virus or antibodies. See your doctor if you become sick within a month of returning from travel in a tropical area, and be prepared to give your complete travel itinerary, so that the doctor can evaluate the possibility that your symptoms were caused by a dengue infection.

Treatment for dengue fever

Specific treatment will be determined by your doctor based on:

  • Your overall health and medical history

  • Extent of the disease

  • Your tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the disease

  • Your opinion or preference

The symptoms of dengue fever are generally treated with bed rest and fluids. Medications may be used to reduce fever, such as acetaminophen, but aspirin should be avoided.

In severe dengue cases, immediate medical attention by doctors familiar with the disease significantly reduces the risk of death.