Dengue
A mosquito-borne viral infection that is often mild or asymptomatic but can progress to life-threatening severe dengue.
What causes Dengue?
Dengue is caused by any of four related viruses, DENV-1 through DENV-4. It spreads mainly through bites from infected Aedes mosquitoes, especially Aedes aegypti. Rare transmission can occur during pregnancy or through blood, organs, or occupational exposure.
Symptoms and what to notice
Fever, severe headache, pain behind the eyes, muscle or joint pain, nausea, vomiting, rash, fatigue, or minor bleeding. Severe abdominal pain, repeated vomiting, bleeding, marked drowsiness or restlessness, breathing difficulty, or signs of shock require urgent care.
How long can it last?
Symptoms usually begin about 5 to 7 days after infection. Fever commonly lasts 2 to 7 days, and many people recover in 1 to 2 weeks, although fatigue may continue. A 24- to 48-hour critical phase can begin as the fever resolves.
How serious is Dengue?
Approximately 1 in 20 patients with dengue develops severe disease. Plasma leakage can cause shock or respiratory distress, and severe bleeding or organ injury can occur. Warning signs often appear after the fever falls.
Treatment and management
There is no dengue-specific antiviral. Care includes rest, oral fluids, acetaminophen when appropriate, follow-up, and urgent hospital management for warning signs or severe disease. Avoid aspirin, ibuprofen, naproxen, and other NSAIDs because they can increase bleeding risk.
Vaccine: who and when?
No dengue vaccine is currently available in the United States. Dengvaxia has an FDA-approved indication for certain previously infected children living in endemic areas, but its manufacturer discontinued it and CDC says it is no longer available in the U.S. Qdenga is authorized in several other countries but is not approved, available, or recommended in the United States.
Cost note: No current U.S. vaccine price applies because no dengue vaccine is available in the country. Evaluation, testing, treatment, and travel-prevention costs vary by provider, location, and insurance.
Trusted source
Patient cost varies by insurance, provider, location, and eligibility. Coverage and public-health access differ, so listed prices are examples rather than guaranteed patient prices. This page is for general education and does not replace individualized medical advice, diagnosis, vaccination assessment, or treatment.
Dengue: Causes, Symptoms, Warning Signs, Treatment, Prevention, and Vaccine Information
Dengue is a mosquito-borne viral illness that can range from an infection with no symptoms to severe, life-threatening disease. It is common in many tropical and subtropical regions and can affect residents as well as travelers. The viruses that cause dengue are spread mainly by infected Aedes mosquitoes, especially Aedes aegypti. These mosquitoes often live near people and can breed in small collections of standing water around homes.
Most people who become ill recover, but dengue deserves careful attention because a person can worsen quickly around the time a fever goes away. Severe abdominal pain, repeated vomiting, bleeding, marked drowsiness or restlessness, breathing difficulty, or signs of dehydration require urgent medical care. There is no specific antiviral medicine for dengue, but timely monitoring, hydration, and well-managed supportive care can substantially improve outcomes.
In the United States, no dengue vaccine is currently available. Dengvaxia has an FDA-approved indication for a narrowly defined group, but its manufacturer discontinued it and CDC states that it is no longer available in the country. Qdenga is used in some other countries but is not approved, available, or recommended in the United States.
Quick Facts
- Cause: Any of four closely related dengue viruses, called DENV-1, DENV-2, DENV-3, and DENV-4.
- Main route of spread: The bite of an infected Aedes mosquito.
- Typical incubation period: About 5 to 7 days, although illness can begin roughly 4 to 10 days after infection.
- Common symptoms: Fever, severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, rash, and minor bleeding.
- Typical duration: Fever commonly lasts 2 to 7 days. Many people recover in 1 to 2 weeks, although fatigue can last longer.
- Critical period: Warning signs often appear as the fever falls. The critical phase usually lasts 24 to 48 hours.
- Treatment: Supportive care, fluids, clinical monitoring, and acetaminophen when appropriate. Aspirin, ibuprofen, and other nonsteroidal anti-inflammatory drugs should be avoided unless a clinician says otherwise.
- U.S. vaccine availability: No dengue vaccine is currently available in the United States.
What Causes Dengue?
Dengue is caused by four related viruses in the flavivirus family. They are referred to as dengue virus types 1 through 4. Infection with one type usually produces long-lasting protection against that same type, but it does not provide permanent protection against the other three. A person can therefore develop dengue more than once during a lifetime.
The relationship between repeat infection and severe disease is one reason dengue vaccine policy is unusually complex. Immune responses can differ depending on whether a person has been infected before and which virus type causes a later infection. Vaccine recommendations and eligibility cannot be determined by age alone; prior infection, country, local transmission, regulatory approval, and product-specific evidence also matter.
Dengue is not caused by dirty food, ordinary person-to-person contact, or cold weather. It is closely connected to the ecology of mosquitoes that thrive in warm climates and urban environments. Rainfall, temperature, water storage practices, travel, population density, and mosquito-control capacity can all influence transmission.
How Dengue Spreads
The usual cycle begins when a mosquito bites a person who has dengue virus in their blood. After the virus develops inside the mosquito, the mosquito can pass it to other people through later bites. The mosquitoes most strongly associated with dengue tend to bite during the day, although bites can occur from morning through evening.
Aedes aegypti commonly lives in and around homes. It lays eggs in water-filled containers such as buckets, flowerpot saucers, tires, toys, rain barrels, uncovered storage tanks, and other objects. Its eggs can survive dry conditions for extended periods, which is why emptying, scrubbing, covering, or discarding water-holding containers is important.
Dengue is not normally spread by coughing, sneezing, touching, or sharing meals. Less common routes have been documented, including transmission during pregnancy, through blood products or organ transplantation, and through laboratory or healthcare exposure. These routes account for a very small share of cases compared with mosquito-borne transmission.
An infected person can help reduce onward spread by avoiding mosquito bites during the period when virus may be present in the blood. Using repellent, sleeping under a bed net, wearing protective clothing, and keeping mosquitoes out of the home protect both the patient and the community.
Where Dengue Occurs
Dengue occurs in many tropical and subtropical areas, including parts of the Caribbean, Latin America, the Pacific Islands, Asia, Africa, and the Middle East. Risk changes over time and may vary within a country. Outbreaks can expand rapidly when susceptible populations, favorable weather, and high mosquito density occur together.
Most dengue cases reported in the continental United States are associated with travel, but local transmission can occur where competent mosquitoes are present. Dengue is endemic in some U.S. territories and freely associated states. Travelers should review destination-specific notices and mosquito precautions shortly before departure because conditions can change.
Returning travelers should tell a clinician exactly where and when they traveled, when symptoms began, and whether they had mosquito exposure. This history helps distinguish dengue from malaria, chikungunya, Zika, influenza, COVID-19, and other illnesses with overlapping symptoms.
Incubation Period and Three Clinical Phases
Symptoms usually begin after an incubation period of about 5 to 7 days. CDC describes dengue as progressing through three possible phases: febrile, critical, and recovery. Not every patient experiences severe disease or a clearly recognizable critical phase.
Febrile Phase
The febrile phase commonly lasts 2 to 7 days. Fever may begin suddenly and can be accompanied by headache, pain behind the eyes, marked muscle and joint pain, nausea, vomiting, rash, and minor bleeding. Because these symptoms are not unique to dengue, testing and clinical context may be needed.
Critical Phase
The critical phase begins near defervescence, which is when the fever falls. It generally lasts 24 to 48 hours. Most patients improve, but a small proportion develop increased permeability of small blood vessels, allowing plasma to leak from the circulation. Severe leakage can cause shock or fluid accumulation that interferes with breathing.
A falling temperature does not always mean the danger has passed. Warning signs may appear at this point, sometimes after a person initially seems better. Close observation and timely care are essential.
Recovery Phase
As leakage stops, the body begins to reabsorb fluid and circulation stabilizes. Appetite, urine output, and general well-being improve. A recovery rash or itching may occur. Medical teams continue to monitor fluid balance because too much intravenous fluid can become harmful as leaked fluid returns to the bloodstream.
Symptoms of Dengue
CDC estimates that about one in four dengue virus infections causes symptoms. Possible symptoms include:
- Fever
- Severe headache
- Pain behind the eyes
- Muscle, bone, or joint pain
- Nausea or vomiting
- Rash
- Fatigue or weakness
- Small red or purple spots caused by bleeding under the skin
- Easy bruising
- Nose or gum bleeding
Symptoms overlap with many other infections. A person cannot reliably diagnose dengue from a rash, fever pattern, or travel history alone. Anyone who is sick after travel to a dengue-risk area should seek medical advice and mention the trip.
Children may have less specific symptoms than adults. Infants, older adults, pregnant people, people with chronic illnesses, and those who cannot maintain fluids may need closer assessment even before classic warning signs develop.
Warning Signs of Severe Dengue
Severe dengue is a medical emergency. Warning signs often begin during the 24 to 48 hours after the fever resolves. Seek urgent care immediately for:
- Severe abdominal pain or tenderness
- Persistent or repeated vomiting
- Bleeding from the nose or gums
- Vomiting blood or passing blood in stool
- Unusual vaginal bleeding
- Marked tiredness, irritability, restlessness, confusion, or difficulty waking
- Rapid breathing, shortness of breath, or fluid around the lungs
- Pale, cold, clammy skin
- Very little urine, dizziness, fainting, or other signs of shock or dehydration
- A rapid rise in hematocrit with a falling platelet count, when identified through medical testing
Severe dengue can involve plasma leakage, shock, major bleeding, liver injury, inflammation of the heart or brain, and failure of other organs. CDC estimates that approximately one in 20 patients with dengue develops severe disease. Prompt recognition and experienced supportive care can lower the risk of death substantially.
Who Is More Likely to Develop Severe Illness?
Anyone with dengue can worsen, but risk assessment is especially important for:
- People with a previous dengue infection
- Infants and adults older than 65
- Pregnant people
- People with diabetes, obesity, asthma, kidney disease, liver disease, bleeding disorders, or other significant conditions
- People taking anticoagulant medicines
- Patients unable to drink enough fluid
- People who live alone or have difficulty reaching medical care quickly
A second dengue infection is associated with a greater risk of severe dengue, but severe illness can also occur during a first recognized infection. Prior infection should not be assumed based only on a past fever in a dengue-risk area.
Dengue During Pregnancy
Dengue during pregnancy requires prompt clinical evaluation. Pregnancy can complicate decisions about hydration, testing, monitoring, and delivery. Dengue virus can rarely pass from a pregnant person to the baby, and infection around delivery may cause illness in the newborn.
Pregnant travelers should use careful mosquito-bite prevention and review destination risk with a healthcare professional. If fever or compatible symptoms develop during or after travel, they should tell their obstetric team immediately. Medicines that increase bleeding risk should not be used without clinical guidance.
Diagnosis and Testing
A clinician considers symptoms, travel or residence, local dengue activity, timing, physical findings, and laboratory results. Blood tests may detect the virus or parts of it early in illness, while antibody tests can be more useful later. The appropriate test depends on the day symptoms began.
During the first week, nucleic acid amplification testing such as RT-PCR or an NS1 antigen test may detect active infection. An IgM antibody test may be added and becomes more useful as the immune response develops. Results must be interpreted carefully because related flaviviruses and previous vaccination or infection can sometimes complicate antibody findings.
Common laboratory changes include low white blood cell counts, falling platelet counts, and elevated liver enzymes. Hematocrit trends can help clinicians assess plasma leakage and guide fluid therapy. Treatment and monitoring should not be delayed when severe dengue is suspected while waiting for confirmation.
Treatment and Home Care
There is no specific antiviral treatment for dengue. Care focuses on supporting circulation, preventing dehydration, controlling fever safely, and identifying warning signs early.
A clinician may recommend home management when a patient has no warning signs, is medically stable, can drink fluids, has normal urine output, and can return quickly if symptoms worsen. Typical advice may include:
- Rest
- Frequent fluids, including oral rehydration solutions when appropriate
- Acetaminophen for fever or pain when safe for the individual
- Monitoring urine output, alertness, breathing, bleeding, and abdominal symptoms
- Follow-up and blood counts when clinically indicated
- Immediate reassessment if any warning sign appears
Avoid aspirin, ibuprofen, naproxen, and other nonsteroidal anti-inflammatory drugs unless a treating clinician specifically directs their use. These medicines can increase bleeding risk. Acetaminophen also requires correct dosing and may not be appropriate for everyone, particularly some people with liver disease.
The critical period often occurs 3 to 8 days after fever begins. Patients and caregivers should not be reassured solely because the temperature returns to normal.
Hospital Treatment for Severe Dengue
Patients with warning signs, severe dengue, or certain coexisting conditions may need hospital care. Treatment can include frequent assessment of blood pressure, pulse pressure, breathing, urine output, mental status, hematocrit, and other laboratory markers.
Intravenous fluids are used carefully when oral hydration is inadequate, warning signs are present, or shock is developing. Both too little and too much fluid can be dangerous. Rates and volumes are adjusted according to the patient’s clinical response and phase of illness.
Clinically significant bleeding may require blood transfusion. Prophylactic platelet transfusion is not routinely recommended simply because the platelet count is low. Routine corticosteroids are also not recommended for dengue unless another condition provides a separate indication.
Severe cases require a facility able to provide close monitoring, rapid fluid management, respiratory support, blood products, and intensive care when needed.
Medicines and Practices to Avoid
Common mistakes can increase risk:
- Do not take aspirin or NSAIDs such as ibuprofen for suspected dengue unless specifically directed by a clinician.
- Do not assume that antibiotics will treat dengue; antibiotics do not work against viruses.
- Do not rely on supplements, herbal products, or so-called platelet boosters in place of clinical care.
- Do not delay urgent assessment because the fever has stopped.
- Do not force excessive plain water without considering electrolytes and clinical guidance.
- Do not request preventive platelet transfusions solely for a laboratory number; transfusion decisions require clinical judgment.
Recovery and Possible Lasting Effects
Many people recover in one to two weeks. Weakness and fatigue can continue after fever and other symptoms resolve. Appetite and normal activity should return gradually, and medical advice should guide return to work, school, travel, or strenuous exercise after significant illness.
People recovering at home should continue preventing mosquito bites for the period recommended by public-health guidance. This reduces the chance that mosquitoes acquire the virus from the patient and transmit it to others.
Persistent or recurrent symptoms should be evaluated rather than automatically attributed to dengue. Other infections or complications can occur at the same time.
Preventing Mosquito Bites
With no dengue vaccine currently available in the United States, mosquito protection is the main preventive tool. Measures include:
- Use an EPA-registered insect repellent and follow label directions.
- Wear long-sleeved shirts and long pants when practical.
- Stay in places with intact window and door screens or air conditioning.
- Use a mosquito net when sleeping in an inadequately screened room or outdoors.
- Treat clothing and gear with permethrin or buy pretreated items; do not apply permethrin directly to skin.
- Protect babies with clothing and mosquito netting, following age-specific repellent guidance.
- Reapply repellent as instructed, especially after sweating or swimming.
Products containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol, or 2-undecanone may be appropriate when used according to the label. Product suitability varies by age and circumstance.
Controlling Mosquitoes Around the Home
Mosquito control is a repeated process, not a one-time cleanup. At least weekly:
- Empty and scrub containers that hold water.
- Turn over, cover, or discard buckets, toys, planters, tires, and other containers.
- Cover water-storage containers tightly.
- Clear roof gutters and drains.
- Repair screens and close gaps around doors and windows.
- Use larvicides for water that cannot be dumped or covered when the product is intended for that purpose.
- Use outdoor insecticides according to label directions when needed.
During illness, the patient should use a bed net and repellent even during daytime. Other household members should also prevent bites.
Dengue Vaccines in the United States
As of September 2026, CDC states that there are currently no dengue vaccines available in the United States.
Dengvaxia
Dengvaxia is the trade name for Dengue Tetravalent Vaccine, Live, manufactured by Sanofi Pasteur. FDA’s product page lists an approved indication for people ages 6 through 16 who have laboratory-confirmed previous dengue infection and live in endemic areas.
Availability is different from regulatory approval. CDC states that Dengvaxia was a three-dose live vaccine formerly recommended for children ages 9 through 16 with laboratory-confirmed previous dengue infection who lived in U.S. endemic areas. Sanofi announced in 2024 that it would discontinue the vaccine because of low global demand, and Dengvaxia is no longer available in the United States.
Dengvaxia was not a routine travel vaccine and was not intended for people without evidence of prior dengue infection. Giving this product to a person who had never been infected could increase the risk of severe disease after a later natural infection. That is why previous-infection testing and the narrow eligibility criteria were essential.
Qdenga
Qdenga, also called TAK-003, is a live attenuated vaccine made by Takeda and used in a number of countries. It is given as two doses three months apart in programs that authorize it. The manufacturer withdrew its U.S. application in 2023. CDC states that Qdenga is not approved, available, or recommended for use in the United States.
Travelers should not assume they can receive Qdenga or Dengvaxia through an ordinary U.S. travel clinic. Advice about a vaccine offered abroad should come from a clinician who understands the country’s authorization, the traveler’s age and dengue history, and current WHO and national recommendations.
Other Vaccine Candidates
Other dengue vaccines are being studied. TV003 is a single-dose candidate developed by the U.S. National Institutes of Health and licensed to several manufacturers. A related product, Butantan-DV, received approval in Brazil in December 2025 for ages 12 through 59; CDC reports that Brazil’s health ministry temporarily suspended its use in June 2026 while adverse-event reports were investigated. This product is not a U.S.-available dengue vaccine.
Vaccine development is challenging because a product should protect safely against all four dengue viruses in people with and without previous infection. Recommendations can change as regulators and public-health agencies review new evidence.
Vaccine Cost and Access
There is no current U.S. retail price to list because no dengue vaccine is available in the United States. Historical prices or prices in other countries do not represent current U.S. access and should not be used to plan care.
Travelers should budget for consultation, mosquito repellent, protective clothing, nets where appropriate, and possible medical care. Insurance coverage for testing or treatment varies. Public-health departments can advise about local testing and outbreak guidance.
Planning Travel to a Dengue-Risk Area
Before travel:
- Check current destination notices and seasonal conditions.
- Pack enough EPA-registered repellent for the entire trip.
- Choose lodging with screens or air conditioning when possible.
- Bring loose long-sleeved clothing and consider permethrin-treated gear.
- Know where to obtain medical care at the destination.
- Review pregnancy, chronic conditions, and medication safety with a clinician.
After travel, monitor for fever or compatible symptoms and seek care promptly. Tell the clinician the destination, dates, and any known mosquito exposure. If dengue is possible, avoid aspirin and NSAIDs until a clinician has evaluated the illness.
Frequently Asked Questions
Is dengue contagious from person to person?
Ordinary contact does not spread dengue. The usual route is through infected mosquitoes. Rare non-mosquito transmission can occur during pregnancy or through blood, organs, or occupational exposure.
Can I get dengue more than once?
Yes. There are four dengue virus types. Infection generally protects against that same type, but a person can later be infected by another type. Repeat infection can increase the risk of severe dengue.
Does a falling fever mean I am recovering?
Not always. Warning signs often begin as the fever resolves, and the critical phase can develop quickly. Severe abdominal pain, persistent vomiting, bleeding, drowsiness, restlessness, breathing difficulty, or reduced urination needs urgent assessment.
Is there a cure for dengue?
There is no dengue-specific antiviral cure. Most patients recover with supportive care, but timely monitoring and carefully managed fluids are lifesaving in severe illness.
What pain medicine can be used?
CDC advises acetaminophen for fever when appropriate and advises avoiding aspirin and NSAIDs such as ibuprofen because they can increase bleeding risk. Individual medical conditions and dosing still require professional guidance.
Is Dengvaxia available in the United States?
No. FDA continues to list an approved indication, but CDC states that the manufacturer discontinued Dengvaxia and it is no longer available in the United States.
Is Qdenga available in the United States?
No. Qdenga is authorized in a number of other countries, but it is not approved, available, or recommended in the United States.
Is there a dengue vaccine for U.S. travelers?
No dengue vaccine is currently available in the United States for travelers or any other group. Travelers should focus on preventing mosquito bites.
When to Seek Medical Care
Contact a healthcare professional promptly for fever or compatible symptoms after living in or traveling to a dengue-risk area. Call ahead and provide the location and travel dates.
Seek emergency care for severe abdominal pain, repeated vomiting, bleeding, fainting, cold or clammy skin, confusion, marked drowsiness or restlessness, breathing difficulty, little urine, or rapid worsening—especially as the fever falls.
This article is for general education. It does not replace diagnosis, individualized treatment, or travel advice from a qualified healthcare professional.
Medical and vaccine information reviewed September 2026.