Dengue Fever



Dengue (DENG-gay) fever is a serious illness commonly occurring in tropical and subtropical regions of the world. It is caused by a virus that passes from person to person through the bite of mosquitoes, and causes high fever and pain in the muscles, joints, and bones.

KEYWORDS

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Aedes mosquito

Arbovirus

Flavivirus

Hemorrhagic fever

What Is Dengue Fever?

Dengue fever is characterized by a sudden high fever and severe pain in the muscles, joints, and bones. (It originally was named "break-bone fever.") The disease is more likely to cause serious illness in children, and some cases are fatal. Dengue fever is caused by four varieties of flaviviruses * , which are part of the arbovirus * family of viruses. Each virus can cause illness, but being infected by one type does not make a person immune * to the other three.

Who Gets Dengue Fever and How?

Dengue fever is widespread in Asia, Africa, South America, and Central America. About 20 million cases develop annually worldwide, and the number of cases is on the rise. It occurs most frequently in highly populated areas, often in cities. Although the number of places where dengue fever is found continues to grow, the disease remains rare in the United States, with most cases appearing in travelers arriving from other countries.

The virus does not spread directly from person to person. Instead, the bite of a mosquito, usually the female Aedes mosquito, transmits the disease. The insect takes in the virus with its meal of blood when it bites an infected person. Because the virus remains in the mosquito for the rest of its life, the mosquito can pass the infection to many people. In areas with large populations of mosquitoes, dengue fever epidemics * can occur.

* flaviviruses (FLAY-vih-vy-ruh-sez) are a group of viruses that includes those that cause dengue fever and yellow fever.

* arbovirus (ar-buh-VY-rus) is a member of a family of viruses that multiply in blood-sucking organisms, such as mosquitoes and ticks, and spread through their bites.

* immune (ih-MYOON) means resistant to or not susceptible to a disease.

* epidemics (eh-pih-DEH-miks) are outbreaks of diseases, especially infectious diseases, in which the number of cases suddenly becomes far greater than usual. Usually, epidemics that involve worldwide outbreaks are called pandemics.

* hemorrhages (HEH-muh-rih-jes) are areas of uncontrolled or abnormal bleeding.

What Are the Symptoms of Dengue Fever?

A sudden high fever, sometimes reaching 104 or 105 degrees Fahrenheit, often is the first symptom. The affected person also may have a flushed (reddish) face. As other symptoms develop, a person might experience muscle, joint, or bone pain; a severe headache; a rash; pain behind the eyes; and signs of small hemorrhages * , such as bleeding gums,

This map shows the occurrence of Dengue fever and its relationship to the regions where the Aedes mosquito lives. The disease is widespread close to the equator, in the tropical areas of Asia, Africa, South America, and Central America, the mosquito's preferred habitat.
This map shows the occurrence of Dengue fever and its relationship to the regions where the Aedes mosquito lives. The disease is widespread close to the equator, in the tropical areas of Asia, Africa, South America, and Central America, the mosquito's preferred habitat.
petechiae * , or a nosebleed. Fever typically lasts 2 to 7 days. Once the fever goes away, the other signs and symptoms usually fade as well. Some symptoms may linger for a few weeks.

How Is Dengue Fever Diagnosed and Treated?

Doctors typically diagnose dengue fever from a patient's history of symptoms and risk factors, including whether that person has been anywhere where dengue fever is found. The doctor looks for three signs: high fever, pain, and rash. These symptoms are known as the dengue triad. To help confirm the diagnosis, doctors may order blood tests or tests on spinal fluid to look for antibodies * to the virus.

No specific treatment exists for dengue fever, but the disease usually clears up on its own. In serious cases, supportive care in a hospital can make recovery easier or even save a person's life. It is important to drink plenty of fluids to avoid dehydration * . Over-the-counter medicine, such as acetaminophen (uh-see-teh-MIH-noh-fen), can relieve pain and fever while the disease runs its course.

* petechiae (puh-TEE-kee-eye) are tiny dots of blood beneath the skin that indicate bleeding from small vessels.

* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually caused by excessive and unreplaced loss of body fluids, such as through sweating, vomiting, or diarrhea.

What Are the Complications of Dengue Fever?

The most serious form of the disease is called dengue hemorrhagic (heh-muh-RAH-jik) fever, which is characterized by high fever, serious hemorrhage, pneumonia, and sometimes failure of the circulatory system * (heart failure) or shock * . People who develop dengue hemorrhagic fever usually require hospitalization, where they receive fluids. It is possible to die from this form of the disease, though most people recover.

What's in a Name?

The history of medicine is replete with fanciful names derived from the symptoms or causes of various medical conditions, like "break-bone fever." Here are just a few:

  • Alice in Wonderland syndrome
    a condition in which a person has delusions or hallucinations
  • cri-du-chat, or cat-cry, syndrome
    a genetic disease with many symptoms, including mental retardation and a high-pitched, catlike mewing cry
  • cauliflower ear
    thickening of the ear with distortion of the contours, also known as boxer's ear
  • happy puppet syndrome
    a genetic disorder marked by a jutting out of the jaw, seizures, and prolonged spasms of laughter
  • jumping disease
    an exaggerated response to being startled, causing a person to jump, fling the arms around, and yell; sometimes called jumping Frenchmen of Maine disease after the French loggers it was first found to affect
  • kissing disease
    infectious mononucleosis, an acute illness that can spread through saliva
  • mitten hand
    a birth defect involving the fusion of several fingers, with a single fingernail
  • vagabond's disease
    discoloration of the skin in people who are exposed to lice bites over a long period of time.

* circulatory (SIR-kyoo-luh-tor-e) system is the system composed of the heart and blood vessels that moves blood throughout the body.

* shock is a serious condition in which blood pressure is very low and not enough blood flows to the body's organs and tissues. Untreated, shock may result in death.

* larvae (LAR-vee) are the immature forms of an insect or worm that hatches from an egg.

How Is Dengue Fever Prevented?

Scientists are working on a vaccine for dengue fever, but one is not yet available. The only way to control the spread of the disease is to reduce mosquito populations. Using pesticides, stocking lakes and ponds with special fish that eat mosquito larvae * , and covering or eliminating small pools of standing water in which the insects breed can help keep mosquito levels in check. People can protect themselves from bites by using insect repellent and wearing clothing that covers much of the body.

See also
Ebola Virus Infection
Travel-related Infections
Yellow Fever

Resources

Organizations

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC offers information about dengue fever at its website.
Telephone 800-311-3435
http://www.cdc.gov

World Health Organization (WHO), Avenue Appia 20, 1211 Geneva 27, Switzerland. WHO posts fact sheets on dengue fever and information about outbreaks in different regions of the world on its website.
Telephone 011-41-22-791-2111
http://www.who.int

Also read article about Dengue Fever from Wikipedia

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