Dengue Fever
Dengue (pronounced Den-gee) fever is a potentially deadly viral infection transmitted by mosquitoes. The disease affects 400 million people worldwide annually, resulting in over 100 million deaths. Until recently, Dengue fever was mostly unknown in the continental United States, but with increasing international travel, the illness has shown up in this country. Some cases of dengue fever are relatively mild and resolve without consequence, but if complications develop, and the disease becomes hemorrhagic, it is life-threatening.
Most cases of dengue fever in the United States occur in travelers who acquired the disease in other countries, but there have been outbreaks in Texas near the Mexican border and in Key West, Florida. Dengue fever is endemic in Puerto Rico, Southeast Asia, parts of the Caribbean, the Pacific Islands and Africa. Presently there is no vaccine against the illness, but prompt diagnosis and supportive treatment can greatly lower the risk of death.
Transmission of Dengue Fever
When a mosquito becomes infected with the virus by biting someone with the disease, whether that individual is symptomatic or not, the insect transmits the illness by biting a healthy person. Dengue fever is not contagious from person to person, but once a person with the disease travels to a region with mosquitoes, transmission to the local residents becomes possible.
Symptoms of Dengue Fever
The onset of symptoms is 4 to 6 days after the disease is contracted. The viral symptoms typically last for a week to 10 days and may be mistaken for symptoms of a lesser viral infection. The symptoms of Dengue fever may include:
- Sudden, high fever
- Severe headache
- Pain behind the eyes
- Severe body aches and joint pain
- Nausea and vomiting
- Widespread rash
- Easy bleeding or bruising
Young children and others who have not had the infection before tend to have milder cases of the illness than older children and adults.
Diagnosis of Dengue Fever
There are a number of blood tests used to diagnose dengue fever. Several years ago, the FDA approved a blood test called DENV Detect IgM Capture ELISA to diagnose dengue fever, but this test may also give positive results when a patient has a related virus like West Nile.
Complications of Dengue Fever
The most serious complication of dengue fever is dengue hemorrhagic fever. Patients with weakened immune systems or those who are suffering a second bout of the infection are at greater risk of developing hemorrhagic fever. The symptoms of this complication include:
- High fever
- Lymph and blood vessel damage
- Bleeding from the nose and gums
- Liver enlargement
- Circulatory problems
- Respiratory difficulty
At worst, these symptoms may lead to massive internal bleeding and shock, a condition known as dengue shock syndrome (DSS) which can easily lead to death.
Treatment of Dengue Fever
Unfortunately, there is no specific treatment for either dengue fever or dengue hemorrhagic fever. For mild symptoms of dengue fever, patients are advised to rest, drink plenty of fluids and take acetaminophen for pain relief. All aspirin products and any medications that increase bleeding risks, such as Advil and Alleve, should be avoided.
If the patient's condition worsens after a few days, hospitalization is often required. In the hospital, the patient can be monitored closely for heart rate, bleeding, and respiratory problems. Lifesaving supportive therapies, like intravenous hydration, electrolyte balancing, and transfusions are also available.
With appropriate medical treatment even patients whose illness has progressed to dengue hemorrhagic fever can recover.
Prevention of Dengue Fever
The only way to prevent dengue fever is to avoid mosquito bites. Methods of protection include: using insect repellent containing DEET, wearing protective clothing outdoors, especially at dawn or dusk, keeping screens repaired, and emptying any standing water.