Dengue Fever

1 What is Dengue Fever?

Dengue fever is an infectious disease that mostly occurs in the tropical and subtropical regions.

It is caused by a virus that is transmitted to human beings by mosquitos. Over a million cases are reported worldwide each year with the majority of cases being from Southeast Asia,western Pacific islands, Latin America and the Caribbean.


The symptoms experienced by infected people depend on the severity of the disease. Symptoms of mild cases include;

These symptoms usually disappear within a week. Severe dengue fever or dengue hemorrhagic fever can lead to

  • severe bleeding,
  • shock (sudden drop in blood pressure)
  • death.

There is currently no vaccine for dengue fever and the best prevention is to reduce the number of mosquitos in areas where dengue fever is common.

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2 Symptoms

People with mild forms of dengue fever may not experience any symptoms. Symptoms usually appear within 4 to 10 days after a mosquito bite.

They may include:

  • A high fever (106 F or 41 C)
  • Headaches
  • Pain in the muscles, joints and even bones
  • Pain behind the eyes
  • Rash that covers the whole body
  • Nausea and vomiting
  • Minor bleeding from the gums or nose.

In severe cases symptoms may worsen and this can lead to damage of blood vessels.

This can lead to bleeding from

  • the mouth,
  • nose
  • under the skin which can appear like bruising.

Other symptoms of severe dengue fever include;

  • abdominal pain,
  • continuous vomiting
  • problems with the lungs, heart and liver.

3 Causes

Dengue fever is caused by one of the four types of dengue viruses. It is spread by mosquitos that live in or near human settlements.

Dengue fever occurs when a mosquito having the dengue fever virus bites a person. This virus then spends part of it's life cycle in the human body where it reproduces.

The new viruses are then transmitted to a mosquito when it bites an infected person. After recovery from dengue fever, a person becomes immune to the virus that caused the disease but not to the other three viruses.

Future infections with the dengue fever virus can increase the risk of developing a much more severe type of dengue fever, hemorrhagic dengue fever.

4 Making a Diagnosis

Making a diagnosis of dengue fever can be challenging since some of the symptoms are similar to those of other diseases like

Doctors use a medical and traveling history to make a diagnosis of dengue fever. Blood tests to identify the dengue virus can also be use.

However, this tests tend to take long and thus waiting for the results can be too late to help doctors make treatment decisions.

5 Treatment

There is no specific treatment for dengue fever.

Treatment is mostly symptomatic. This involves giving the patient pain medication like acetaminphen (Tylenol).

Painkillers that increase the risks of bleeding like aspirin and ibuprofen (Advil, Motrin IB) should be avoided as they can increase the bleeding.

Drinking plenty of fluids can also be helpful as it prevents a person from being dehydrated which can be caused by vomiting.

Patients in severe cases may require

  • supportive treatment,
  • intravenous replacement of fluids and electrolytes,
  • frequent monitoring of the blood pressure
  • blood transfusion in cases of severe bleeding.

6 Prevention

The best prevention of dengue fever is to reduce the number of mosquitos in areas where the disease is common.


Although six dengue vaccines have been developed, they are not yet available.

The furthest vaccine that has been developed is a three-dose vaccine for children. The results of a phase III trail which were published in 2014 showed that vaccine was safe and was able to prevent dengue fever infections slightly more than half the time.

Those who were vaccinated but still became infected had a milder course of the disease as compared to those who were not vaccinated. The company that makes this vaccine hasn't yet annunced any plans to seek approval to market the vaccine.

Avoiding being bitten by mosquitos especially for people living or travelling to tropical regions.

This can be achieved by:

  • Living in an air-conditioned or well-screened housing
  • Wearing protective clothing like long-sleeved shirts, long pants socks and shoes especilly when going into mosquito infested areas
  • Reducing the breeding habitat to lower mosquito populations                                                        

7 Risks and Complications

Factors that increase the risk of developing dengue fever include:

  • Living or travelling in tropical areas like Southeat Asia, the western Pacific Islands, Latin America and the Caribbean.
  • Having a previous infection with a dengue fever virus. This can also increase the risk of developing severe symptoms of dengue fever.

In severe cases, dengue fever can cause damage to the lungs, heart or liver.

Dengue fever can also cause a drastic drop in blood pressure. This can cause shock and even death in some cases.

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