Dengue fever
O'nyong-nyong fever; Dengue-like disease; Breakbone fever; Dengue hemorrhagic fever
Dengue fever is a virus-caused disease that is spread by mosquitoes. Dengue in its mild form causes fever and a rash and lasts about a week. Severe dengue can cause shock, internal bleeding, and death. About 1 out of 20 people with dengue will develop severe dengue within a few hours after symptoms start. The main risk factor for severe dengue is a prior infection with dengue.
There are many different species of mosquito, which can carry some of the world's most common and significant infectious diseases, including West Nile, Malaria, yellow fever, viral encephalitis, and dengue fever. (Image courtesy of the Centers for Disease Control and Prevention.)
Dengue fever, or West Nile fever, is a mild viral illness transmitted by mosquitoes which causes fever, rashes and muscle and joint aches. Treatment includes rehydration and recovery is expected. A second exposure to the virus can result in Dengue hemorrhagic fever, a life-threatening illness.
This illustration shows an adult southern house mosquito. This mosquito feeds on blood and is the carrier of many diseases, such as encephalitis, West Nile, dengue fever, yellow fever, and others. (Image courtesy of the Centers for Disease Control and Prevention.)
Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito lays the eggs one at a time sticking them together in the shape of a raft. An egg raft can contain from 100 to 400 eggs. The eggs go through larval and pupal stages and feed on micro-organisms before developing into flying mosquitoes. (Image courtesy of the Centers for Disease Control and Prevention.)
This picture shows mosquito larvae, an early stage of the mosquito life cycle. (Image courtesy of the Centers for Disease Control and Prevention.)
These are mosquito pupa. This is another stage in the development of the mosquito. (Image courtesy of the Centers for Disease Control and Prevention.)
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.
Causes
Dengue fever is caused by 1 of 4 different but related viruses. It is spread by the bite of mosquitoes, most commonly the mosquito Aedes aegypti, which is found in tropic and subtropic regions. This area includes parts of:
- The Indonesian archipelago into northeastern Australia
- South and Central America
- Southeast Asia
- Sub-Saharan Africa
- The Caribbean (including Puerto Rico and US Virgin Islands)
Dengue fever is rare in the US mainland, but has been found in Hawaii, Florida, and Texas. Since 2022, dengue has also been reported in California and Arizona.
Many cases in the United States occur when someone travels to an area where dengue is present and returns home with the illness. Dengue cannot spread from human to human.
Symptoms
Dengue fever begins with a sudden high fever, often as high as 105°F (40.5°C), 4 to 7 days after the infection.
A flat, red rash may appear over most of the body 2 to 5 days after the fever starts. A second rash, which looks like the measles, appears later in the disease. Infected people may have increased skin sensitivity and are very uncomfortable.
Other symptoms include:
- Fatigue
- Headache (especially behind the eyes)
- Joint aches (often severe)
- Muscle aches (often severe)
- Nausea and vomiting
- Swollen lymph nodes
- Cough
- Sore throat
- Nasal stuffiness
Symptoms of severe dengue can occur 24 to 48 hours after fever has gone away. Severe symptoms include:
- Severe stomach pain and tenderness
- Vomiting often (at least 3 times in 24 hours)
- Bleeding from the nose or gums
- Vomiting blood or passing blood in the stools or urine
- Bleeding under the skin (looks like bruises)
- Difficulty breathing, rapid breathing
- Feeling tired, restless, or irritable
If you or anyone you know has symptoms of severe dengue, call 911 or the local emergency number right away.
Exams and Tests
Tests that may be done to diagnose this condition include:
- Antibody titer for dengue virus types
- Complete blood count (CBC)
- Polymerase chain reaction (PCR) test for dengue virus types
- Liver function tests
Treatment
There is no specific treatment for dengue fever. Fluids are given if there are signs of dehydration. Acetaminophen (Tylenol) is used to treat a high fever.
Avoid taking aspirin, ibuprofen (Advil, Motrin), and naproxen (Aleve). They may increase bleeding problems.
Severe dengue is a medical emergency. It must be treated immediately at a hospital. Treatment for severe dengue is supportive and may include:
- Fluids given through a vein (IV)
- Oxygen
- Blood pressure management
- Blood transfusions
Outlook (Prognosis)
Mild cases of dengue generally last a week or more. Although uncomfortable, mild dengue fever is not deadly. People with the condition should fully recover. In some Latin American and Asian countries, severe dengue is a leading cause of death and severe illness. Early detection and treatment of severe dengue can greatly reduce the risk of death.
Possible Complications
Untreated, dengue fever may cause the following health problems:
- Febrile convulsions
- Severe dehydration
- Death
When to Contact a Medical Professional
Contact your health care provider if you have traveled in an area where dengue fever is known to occur and you have symptoms of the disease.
Prevention
To prevent dengue, take steps to prevent mosquito bites:
- Use insect repellent daily and reapply as needed.
- Wear loose-fitting, long-sleeved shirts and pants.
- Spray clothing and hats with permethrin (an insecticide that repels mosquitos), but do not apply to skin.
- Sleep under mosquito netting if sleeping outside or if there are no screens on windows.
- Limit outdoor activity during mosquito season, especially when they are most active, at dawn and dusk.
When traveling, check to see if dengue is present in the area you will be traveling. Bring protective clothing, mosquito repellent, and netting if needed.
References
Centers for Disease Control and Prevention website. About dengue.
Endy TP. Viral febrile illnesses and emerging pathogens. In: Ryan ET, Hill DR, Solomon T, Aronson NE, Endy TP, eds. Hunter's Tropical Medicine and Infectious Disease. 10th ed. Philadelphia, PA: Elsevier; 2020:chap 36.
Thomas SJ, Endy TP, Rothman AL, Barrett AD. Flaviviruses (dengue, yellow fever, Japanese encephalitis, West Nile encephalitis, Usutu encephalitis, St. Louis encephalitis, tick-borne encephalitis, Kyasanur forest disease, Alkhurma hemorrhagic fever, Zika). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 153.
World Health Organization website. Dengue and severe dengue.
Version Info
Last reviewed on: 12/4/2022
Reviewed by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 08/22/2024.
