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Dengue fever is a mosquito-borne illness that occurs worldwide in tropical and subtropical regions. Mild dengue fever is characterized by a high fever and flu-like symptoms. Dengue hemorrhagic fever, also known as severe dengue fever, can result in severe bleeding, a sudden drop in blood pressure (shock), and death.
Every year, millions of people become infected with dengue. Southeast Asia, the western Pacific islands, Latin America, and Africa are the most affected by dengue fever. However, the disease has spread to new areas, including local outbreaks in Europe and the southern United States.
Dengue fever vaccines are being developed by researchers. For the time being, in areas where dengue fever is common, the best ways to avoid infection are to avoid mosquito bites and to take steps to reduce the mosquito population.
WHAT ARE THE SYMPTOMS OF DENGUE FEVER?
Many people show no signs or symptoms of a dengue infection.
When symptoms do appear, they may be misdiagnosed as other illnesses, such as the flu, and usually appear four to ten days after being bitten by an infected mosquito.
Dengue fever causes a high fever of 104 degrees Fahrenheit (40 degrees Celsius) as well as any of the following signs and symptoms:
- Headache
- Pain in the muscles, bones, or joints
- Nausea
- Vomiting
- Pain behind the eyes
- Swollen glands
- Rash
Most people recover in about a week. Symptoms can worsen and become life-threatening in some cases. This condition is known as severe dengue, dengue hemorrhagic fever, or dengue shock syndrome.
When your blood vessels become damaged and leaky, you develop severe dengue. In addition, the number of clot-forming cells (platelets) in your blood decreases. Shock, internal bleeding, organ failure, and even death can result from this.
Severe dengue fever, which is a life-threatening emergency, can manifest quickly. The warning signs usually appear within the first day or two after your fever has subsided, and they may include:
- Extreme stomach ache
- Vomiting that persists
- Bleeding from the gums or the nose
- Urine, stools, or vomit containing blood
- Bleeding beneath the skin, which may appear as bruising
- Breathing that is difficult or rapid
- Fatigue
- Irritability or agitation
WHAT ARE THE CAUSES OF DENGUE FEVER?
Dengue fever can be caused by any of four different types of dengue viruses. You cannot contract dengue fever by being in the presence of an infected person. Dengue fever is instead spread by mosquito bites.
The two types of mosquitos that most commonly transmit dengue viruses are found in and around human dwellings. When a mosquito bites a dengue virus-infected person, the virus enters the mosquito. The virus then enters the bloodstream of the person who is bitten by the infected mosquito and causes an infection.
After recovering from dengue fever, you have long-term immunity to the virus that infected you, but not to the other three types of dengue fever viruses. This means you could be infected again by one of the other three virus types in the future. If you get dengue fever for the second, third, or fourth time, your chances of developing severe dengue fever increase.
WHAT ARE THE RISK FACTORS OF DENGUE FEVER?
You are more likely to get dengue fever or a more severe form of the disease if you:
- You live in or visit tropical areas: Being in tropical and subtropical areas increases your chances of contracting the dengue fever virus. Southeast Asia, the western Pacific islands, Latin America, and Africa are particularly high-risk areas.
- You've had dengue fever before: If you have previously been infected with a dengue fever virus, you are more likely to develop severe symptoms if you get dengue fever again.
WHAT ARE THE COMPLICATIONS OF DENGUE FEVER?
Internal bleeding and organ damage can result from severe dengue fever. Blood pressure can fall to dangerously low levels, resulting in shock. Severe dengue fever can be fatal in some cases.
Women who contract dengue fever while pregnant may be able to pass the virus to their babies during childbirth. Furthermore, babies born to mothers who contract dengue fever during pregnancy are at a higher risk of preterm birth, low birth weight, or fetal distress.
HOW IS DENGUE FEVER DIAGNOSED?
Dengue fever can be difficult to diagnose because its signs and symptoms are similar to those of other diseases such as chikungunya, Zika virus, malaria, and typhoid fever.
Your doctor will almost certainly inquire about your medical and travel history. Make sure to describe your international trips in detail, including the countries you visited and the dates, as well as any mosquito contact you may have had.
Your doctor may also draw a blood sample to be tested in a lab for evidence of dengue virus infection.
WHAT ARE THE TREATMENTS FOR DENGUE FEVER?
There is no specific treatment for dengue fever.
Drink plenty of fluids while recovering from dengue fever. If you have any of the following signs and symptoms of dehydration, contact your doctor right away:
- Reduced urination
- There are few or no tears.
- Lips or mouth that are dry
- Lethargy or perplexity
- Cold or clammy extremities
Acetaminophen (Tylenol, and others) is an over-the-counter (OTC) medication that can help relieve muscle pain and fever. However, if you have dengue fever, you should avoid other over-the-counter pain relievers such as aspirin, ibuprofen (Advil, Motrin IB, and others), and naproxen sodium (Aleve). These pain relievers have been linked to an increase in the risk of dengue fever bleeding complications.
If you have severe dengue fever, you may require the following:
- Supportive care in a hospital
- Intravenous (IV) fluid and electrolyte replacement
- Monitoring of blood pressure
- Transfusion to compensate for blood loss
HOW IS DENGUE FEVER PREVENTED?
Vaccine
In areas where dengue fever is common, one dengue fever vaccine (Dengvaxia) is approved for people aged 9 to 45 who have previously had dengue fever. The vaccine is administered in three doses over the course of a year.
The vaccine is only approved for people who have a documented history of dengue fever or who have a blood test that shows previous infection with one of the dengue viruses — a condition known as seropositivity. Receiving the vaccine appears to increase the risk of severe dengue fever and hospitalization due to dengue fever in people who have never had dengue fever before (seronegative).
Dengvaxia is not available to travelers or residents of the continental United States. However, in 2019, the US Food and Drug Administration approved the vaccine for people aged 9 to 16 who have previously had dengue fever and live in the US territories of American Samoa, Guam, Puerto Rico, and the US Virgin Islands — where dengue fever is common.
Avoid mosquito bites
The World Health Organization emphasizes that the vaccine is not an effective tool in reducing dengue fever in areas where the illness is common on its own. The main methods for preventing the spread of dengue fever are still avoiding mosquito bites and controlling the mosquito population.
If you live in or travel to a dengue-infested area, the following tips may help reduce your risk of mosquito bites:
- Stay in air-conditioned or well-screened housing: The mosquitoes that transmit dengue viruses are most active from dawn to dusk, but they can bite at any time of day or night.
- Put on protective clothing: Wear a long-sleeved shirt, long pants, socks, and shoes when going into mosquito-infested areas.
- Use a mosquito repellent: Permethrin can be used to treat your clothing, shoes, camping equipment, and bed netting. You can also buy clothing that already contains permethrin. Use a repellent with at least a 10% concentration of DEET on your skin.
- Reduce mosquito breeding grounds: Mosquitoes that carry the dengue virus typically live in and around houses, breeding in standing water that can accumulate in items such as used automobile tires. You can help reduce mosquito populations by removing places where they lay their eggs. Empty and clean containers that hold standing water, such as planting containers, animal dishes, and flower vases, at least once a week. Between cleanings, keep standing water containers covered.