Dengue

What is dengue?

Dengue is a viral disease spread to people through mosquito bites. It is caused by any one of four closely related dengue viruses. The viruses are transmitted to people when they are bitten by an infected Aedes species mosquitoes (Aedes aegypti or Aedes albopictus).

Who gets dengue and how is it spread?

People who are bitten by an Aedes mosquito infected with dengue virus can become ill. About one in four people infected with dengue virus will get sick. Of those who become ill, about one in 20 people will become severely ill. Pregnant women can transmit dengue virus to the fetus during pregnancy or around time of birth. Rarely, dengue can be spread to people through laboratory or healthcare setting exposures, such as blood transfusions, organ transplants, or needlestick injuries.

Are mosquitoes in Virginia able to spread dengue?

Aedes albopictus mosquitoes are commonly found throughout Virginia. While Aedes aegypti mosquitoes have been identified in Virginia, they are only found sporadically. Aedes mosquitoes commonly bite people. They typically lay eggs in containers that are near people and hold water, like buckets, bowls, animal dishes, flowerpots, and vases.

What are the symptoms of dengue?

The major symptom of dengue is fever. Other symptoms include headache, pain behind the eyes, joint pain, nausea, vomiting, and muscle and/or bone pain. About 1 in 20 patients with dengue progress to develop a severe, life-threatening disease called severe dengue.  Severe dengue can start 1-2 days after the fever goes away. Severe dengue symptoms can include stomach pain or tenderness, persistent vomiting (which can contain blood), bleeding from the nose or gums, and blood in the stool.

How soon after exposure do symptoms appear?

Symptoms of dengue usually begin 5–7 days after a person is bitten by an infected mosquito. Illness usually lasts for 2–7 days.

How is dengue diagnosed?

Dengue can be diagnosed in the early stages of illness by testing serum samples for the dengue virus. This test is reliable and can detect the virus during the first seven days after illness onset. After seven days of illness, serologic tests can be used to assess a person's antibody response to see if they might have been exposed to a dengue virus.

What is the treatment for dengue?

Persons suffering from dengue should consult a physician for care. There is no specific medication for treatment of  dengue, other than supportive care. Persons who think they might have dengue should only use pain relievers (analgesics) with acetaminophen. Due to the potential for bleeding during dengue virus infection, aspirin, aspirin-containing drugs, or aspirin-like products, such as ibuprofen or naproxen, should be avoided. Additionally, one should also rest, drink plenty of fluids to prevent dehydration, and avoid mosquito bites while febrile.

Do people who have been in contact with someone with dengue need to be tested and treated?

Contacts of people with dengue should be tested if they exhibit symptoms of dengue virus infection and have a history of travel or mosquito exposure. Dengue is not transmitted directly from person to person, but an infected person can pass the virus to mosquitoes, potentially exposing others.

How can dengue be prevented?

Prevention of mosquito bites is the best protection against dengue:

• Use insect repellent containing DEET, picaridin, IR3535, or oil of lemon eucalyptus on exposed skin and/or clothing. The repellent/insecticide permethrin can be used on clothing to protect through several washes. Always follow the directions on the package.
• Wear long sleeves and pants when outside.
• Have secure, intact screens on windows and doors to help keep mosquitoes out.
• Eliminate mosquito breeding sites around the home by emptying standing water from flowerpots, buckets, barrels, and other containers. Drill holes in tire swings so that water drains out. Empty children’s wading pools and store on their side after use.

How can I get more information about dengue?

• If you have concerns about dengue, contact your healthcare provider.
• Call your local health department. You can find your local health department at vdh.virginia.gov/health-department-locator/
• Visit the CDC’s Dengue Fever page at cdc.gov/dengue/ for more information.