Dengue Fever Causes, Symptoms, Treatment, Prevention and Complication

Early diagnosis and treatment of dengue is critical as epidemics of the disease become larger and more frequent. An estimated 50 to 100 million people contact dengue each year in over 100 countries. Recent explosive outbreaks of the disease have occurred in Brazil with 120,570 cases so far in 2008 and Venezuela with more than 80,000 cases in 2007. Left untreated, patients may experience hemorrhage and shock, leading to death.

Overview

Dengue fever is an infectious disease carried by mosquitoes and caused by any of four related dengue viruses. This disease used to be called "break-bone" fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking, hence the name. Health experts have known about dengue fever for more than 200 years.

Dengue fever is found mostly during and shortly after the rainy season in tropical and subtropical areas of

• Africa
• Southeast Asia and China
• India
• Middle East
• Caribbean and Central and South America
• Australia and the South and the Central Pacific

An epidemic in Hawaii in 2001 is a reminder that many locations in the United States are susceptible to dengue epidemics because they harbor the particular types of mosquitoes that transmit dengue virus.

Worldwide, 50 to 100 million cases of dengue infection occur each year. This includes 100 to 200 cases in the United States, mostly in people who have recently traveled abroad. Many more cases likely go unreported because some healthcare providers do not recognize the disease.

During the last part of the 20th century, many tropical regions of the world saw an increase in dengue cases. Epidemics also occurred more frequently and with more severity. In addition to typical dengue, dengue hemorrhagic fever (DHF) and dengue shock syndrome also have increased in many parts of the world. Globally, there are an estimated several hundred thousand cases of DHF per year.

Cause

Dengue fever can be caused by any one of four types of dengue virus: DEN-1, DEN-2, DEN-3, and DEN-4. You can be infected by at least two if not all four types at different times during your lifetime, but only once by the same type.

Transmission

You can get dengue virus infections from the bite of an infected Aedes mosquito. Mosquitoes become infected when they bite infected humans, and later transmit infection to other people they bite. Two main species of mosquito, Aedes aegypti and Aedes albopictus, have been responsible for all cases of dengue transmitted in this country. Dengue is not contagious from person to person.

Symptoms

The principal symptoms of dengue are (CDC 2009):

High fever and at least two of the following:

• Severe headache
• Severe eye pain (behind eyes)
• Joint pain
• Muscle and/or bone pain
• Rash
• Mild bleeding manifestation (e.g., nose or gum bleed, petechiae, or easy bruising)
• Low white cell count

Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.

Watch for warning signs as temperature declines 3 to 7 days after symptoms began.
Go IMMEDIATELY to an emergency room or the closest health care provider if any of the following warning signs appear:

• Severe abdominal pain or persistent vomiting
• Red spots or patches on the skin
• Bleeding from nose or gums
• Vomiting blood
• Black, tarry stools (feces, excrement)
• Drowsiness or irritability
• Pale, cold, or clammy skin
• Difficulty breathing

Diagnosis

Your healthcare provider can diagnose dengue fever by doing two blood tests, 2 to 3 weeks apart. The tests can show whether a sample of your blood contains antibodies to the virus. In epidemics, a healthcare provider often can diagnose dengue by typical signs and symptoms.

Treatment

There is no specific treatment for classic dengue fever, and most people recover within 2 weeks. To help with recovery, healthcare experts recommend

• Getting plenty of bed rest
• Drinking lots of fluids
• Taking medicine to reduce fever

The Centers for Disease Control and Prevention advises people with dengue fever not to take aspirin. Acetaminophen or other over-the-counter pain-reducing medicines are safe for most people.

For severe dengue symptoms, including shock and coma, early and aggressive emergency treatment with fluid and electrolyte replacement can be lifesaving.

Dengue Fever Prevention

The best way to prevent dengue virus infection is to take special precautions to avoid being bitten by mosquitoes. Several dengue vaccines are being developed, but none is likely to be licensed by the Food and Drug Administration in the next few years.

When outdoors in an area where dengue fever has been found

• Use a mosquito repellent containing DEET, picaridin, or oil of lemon eucalyptus
• Dress in protective clothing—long-sleeved shirts, long pants, socks, and shoes

Because Aedes mosquitoes usually bite during the day, be sure to take precautions, especially during early morning hours before daybreak and in the late afternoon before dark.

Other precautions include:

• Keeping unscreened windows and doors closed
• Keeping window and door screens repaired
• Getting rid of areas where mosquitoes breed, such as standing water in flower pots, containers, birdbaths, discarded tires, etc.

Complications of Dengue Fever

Most people who develop dengue fever recover completely within 2 weeks. Some, especially adults, may be tired and/or depressed for several weeks to months after being infected with the virus.

The more clinically severe dengue hemorrhagic fever and dengue shock syndromes can result in vascular (blood vessel) and liver damage, and can be life-threatening.

Related Topics:
Natural Cure for Dengue, Tawa-tawa?
Dengue Fever Cases in the Philippines
Philippines' Dengue Cases at 77,000, Feared to Further Increase by Year's End

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Source:
The above health article is reprinted from material provided by the National Institute of Allergy and Infectious Diseases (NIAID).

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