Symptoms

Many people, especially children and teens, may experience no signs or symptoms during a mild case of dengue fever. When symptoms do occur, they usually begin four to seven days after you are bitten by an infected mosquito.

Dengue fever causes a high fever — 104 F degrees — and at least two of the following symptoms:

• Headache
• Muscle, bone and joint pain
• Nausea
• Vomiting
• Pain behind the eyes
• Swollen glands
• Rash
• Bleeding from your gums or nose
• Blood in your urine, stools or vomit
• Bleeding under the skin, which might look like bruising
• Difficult or rapid breathing
• Cold or clammy skin (shock)
• Fatigue
• Irritability or restlessness

Diagnosis

Diagnosing dengue fever can be difficult because its signs and symptoms can be easily confused with those of other diseases such as malaria, leptospirosis, and typhoid fever.

Your doctor will likely ask about your medical and travel history. Be sure to describe international trips in details, including the countries you visited and the dates, as well as any contact you may have had with mosquitoes.

Certain laboratory tests can detect evidence of the dengue viruses, but test results usually come back too late to help direct treatment decisions

Causes

The vector-borne dengue virus infection spreads via the bite of a striped Aedes aegypti and Aedes albopictus mosquito that has previously bitten an infected person. The mosquito flourishes during rainy seasons but can breed in water-filled flowerpots, plastic bags, and cans year-round. One mosquito bite can cause the disease.

The virus is not contagious and cannot spread directly from person to person. It is mosquito-borne, so there must be a person-to-mosquito-to-another-person pathway. A mosquito bites a dengue-infected person and becomes infected with dengue. That mosquito then bites another person and passes the dengue virus infection to that person. The full life cycle of the virus involves the Aedes mosquito as the vector (transmitter) and the human as the source of infection.

Prevention

There is no vaccine to prevent dengue fever. The best method of protection is to avoid mosquito bites and to reduce the mosquito population. When in a high-risk area, you should:

• avoid heavily populated residential areas
• use mosquito repellent indoors and outdoors
• wear long-sleeved shirts and pants tucked into socks
• use air conditioning instead of opening windows
• ensure that windows and door screens are secure and any holes are repaired
• use mosquito nets if sleeping areas are not screened

There is no cure or specific treatment for dengue. You can only relieve the symptoms until the infection has gone.

You can usually look after yourself at home.

The following may help:

• Take Paracetamol to relieve pain and fever. Do not take aspirin or ibuprofen, as these can cause bleeding problems in people with dengue
• Drink plenty of fluids to prevent dehydration – if you are currently abroad, only drink bottled water from a bottle that was properly sealed
• Get plenty of rest
• You should start to feel better after about one week, although it may be a few weeks before you feel your normal self again. 

Dengue fever is a disease spread by the Aedes aegypti mosquito and is caused by one of four dengue viruses. Once you are infected with one of the dengue viruses, you will develop immunity to that virus for the rest of your life. However, you can still be infected with the other three viruses. It is possible to get all four dengue viruses in your lifetime. The viruses that cause dengue fever are related to those that cause yellow fever and West Nile virus infection.

The Center for Disease Control and Prevention estimates that at least 400 million cases of dengue fever occur across the globe every year. Tropical regions are heavily affected.