What is Dengue Fever?

Dengue Fever is an illness caused by infection with one of four serotypes of a virus belonging to the genus Flavivirus. Infection with one of these serotypes does not provide cross-protective immunity, so a person living in an area where Dengue Fever transmission occurs can have four dengue fever infections during his or her lifetime.

Who gets Dengue Fever?

Dengue Fever occurs primarily in tropical areas, including the Caribbean and Mexico in North America. Anyone living in or visiting tropical areas may become ill with Dengue Fever.

How is Dengue Fever spread?

Dengue Fever is spread through the bite of certain species of mosquitoes, but only if they are infected with the Dengue Fever virus. Capable species of mosquitoes pick up the Dengue Fever infection by biting a human who is ill with Dengue Fever. Two capable mosquito vectors are present in the Americas, including the United States, Aedes aegypti, and Aedes albopictus. Nearly all cases of Dengue Fever which are diagnosed in the United States are a direct result of recent travel to tropical areas outside the United States.

What are the symptoms of Dengue Fever?

The classic symptoms of Dengue Fever include a high fever that may last from 5 to 7 days; intense headache; eye, joint and muscle pain; and a rash. The rash typically begins on the arms or legs three to four days after the beginning of the fever. Symptoms can range widely in severity. Some individuals have very slight symptoms while others may have a life-threatening illness (Dengue Hemorrhagic Fever). Symptoms usually resolve within 1 to 2 weeks.

Dengue Hemorrhagic Fever is the most serious form of this illness. Individuals with Dengue Hemorrhagic Fever experience blood clotting problems which result in bleeding and shock (extremely low blood pressure). Hospitalization is usually required.

How soon do symptoms occur?

Symptoms usually occur within 5 to 6 days after the bite of an infected mosquito, but they may be delayed for up to 2 weeks.

How is Dengue Fever diagnosed?

Dengue Fever is diagnosed by clinical symptoms and by specific blood tests.

Can Dengue Fever be treated?

There is no curative treatment for Dengue Fever. If there are no complications, recovery will occur within 1 to 2 weeks. Hospital care with intravenous fluids is usually necessary for individuals with Dengue Hemorrhagic Fever.

How long is an infected person infectious to others?

An individual infected with Dengue Fever is not directly infectious to other individuals except through sharing of blood contaminated needles. Untreated individuals, if bitten by Dengue Fever-capable mosquitoes, could infect a small number of mosquitoes. These could transmit Dengue Fever if they subsequently bite another human at least 1 to 2 weeks later, depending upon environmental conditions.

I'm traveling to a tropical area where Dengue Fever is present. What should I do?

Try to avoid being bitten by mosquitoes. This includes sleeping in areas screened from mosquitoes, wearing long sleeves and pants, and using mosquito repellents and insecticides.

Is there a vaccine to prevent Dengue Fever?

There is no vaccine which can prevent Dengue Fever, however such vaccines are in development.