Dengue fever is a disease spread by the Aedes aegypti mosquito and caused by one of four dengue viruses that are closely related. The viruses that cause dengue fever are related to those that cause yellow fever and West Nile virus infection.
Every year, it is estimated that at least 100 million cases of dengue fever occur across the globe. Tropical regions remain heavily affected. Areas that have the greatest risk of infection include:
- Sub-Saharan Africa
- Central America
- The Caribbean (except the Cayman Islands and Cuba)
- Pacific Islands
- South America (except Argentina, Chile, and Paraguay)
- Southeast Asia
- Southern China
- Northern parts of Australia
Very few cases occur in the United States. Most of the cases that are diagnosed occur in individuals who contracted the disease while traveling abroad. However, risk of infection is increasing for residents of Texas that live in areas that share a border with Mexico. Additionally, cases have been on the rise in the Southern United States. As recently as 2009, an outbreak of dengue fever was identified in Key West, Florida.
Dengue fever is transmitted via the bite of a mosquito harboring the dengue virus. Person-to-person transmission does not occur.
If you contract dengue fever, symptoms usually begin about four to seven days after the initial infection. In many cases, symptoms will be mild. They may be mistaken for symptoms of the flu or another infection. Young children and people who have never experienced infection may have a milder illness than older children and adults. Symptoms generally last for about 10 days and can include:
- sudden, high fever
- severe headache
- swollen lymph glands
- severe joint pain and muscle pain
- skin rash (appearing between two and five days after the initial fever)
- mild to severe nausea
- mild to severe vomiting
- mild bleeding from the nose or gums
- mild bruising on the skin
- febrile convulsions
A small percentage of individuals who have dengue fever can develop a more serious form of disease, dengue hemorrhagic fever.
Dengue Hemorrhagic Fever
The risk factors for developing dengue hemorrhagic fever include:
- having antibodies to dengue virus from a previous infection
- being under the age of 12
- being female
- Caucasian race
- weakened immune system
This rare form of the disease is characterized by:
- high fever
- damage to the lymphatic system
- damage to blood vessels
- bleeding from the nose
- bleeding from the gums
- liver enlargement
- circulatory system failure
The symptoms of dengue hemorrhagic fever can trigger dengue shock syndrome. Dengue shock syndrome is severe, and can lead to massive bleeding and even death.
Doctors use blood tests to check for viral antibodies or the presence of infection. If you experience dengue symptoms after traveling outside the country, you should see a healthcare provider to check if you are infected.
There is no medication or treatment specifically for dengue infection. If you believe you may be infected with dengue, you should use over-the-counter pain relievers to reduce your fever, headache, and joint pain. However, aspirin and ibuprofen can cause more bleeding and should be avoided.
Your doctor should perform a medical exam, and you should rest and drink plenty of fluids. If you feel worse after the first 24 hours of illness — once your fever has gone down — you should be taken to the hospital as soon as possible to check for complications.
There is no vaccine to prevent dengue fever. The best method of protection is to avoid mosquito bites and to reduce the mosquito population. When in a high-risk area, you should:
- avoid heavily populated residential areas.
- use mosquito repellent indoors and outdoors.
- wear long-sleeved shirts and pants tucked into socks.
- use air conditioning instead of opening windows.
- ensure that window and door screens are secure, and any holes repaired.
- use mosquito nets if sleeping areas are not screened.
Reducing the mosquito population involves getting rid of mosquito breeding areas. These areas include any place that still water can collect, such as birdbaths, pet dishes, empty planters/flower pots/cans or any empty vessel. These areas should be checked, emptied, or changed regularly.
If a family member is already ill, it is important to protect yourself and other family members from mosquito bites. To help prevent the disease from spreading, consult a physician anytime you experience symptoms of dengue fever.