Last summer, I received a phone call from a travelling family who had been in Laos at the time. Their five-year-old son was suffering from high fever, with headaches and joints pain, and they suspected he was infected with Dengue Fever.


Most travellers in developing countries are afraid of malaria – a disease everyone knows. Many of the travellers even take prophylaxis for malaria.

Dengue Fever is a less known disease, although it is much more common in travellers than malaria.


So what is Dengue Fever?

Dengue Fever is a febrile illness, caused by one of the four Dengue viruses. The viruses are transmitted to humans by the bite of an infected mosquito.

With more than one-third of the world’s population living in areas at risk for infection (more than 100 countries worldwide) Dengue virus is the leading cause of illness and death in the tropics and subtropics. As many as 400 million people are infected every year…

Although the geographic distribution of Dengue Fever is similar to that of malaria, Dengue is more

of a risk in urban and residential areas that is malaria.

Dengue Map ( shows up-to-date information on areas of

ongoing infection.


How to prevent Dengue FevDengue Fever Symptoms and what to do if you suspect you might be infected?

The principal symptoms of Dengue fever are a high fever that lasts 2 to 7 days, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (i.e nose or gums bleeding or easy bruising).

Generally, younger children and those with their first Dengue infection have a milder illness than older children and adults. An estimated 75% of infections are asymptomatic.

When the fever declines, most of the patients will get better, but some will develop more symptoms, including persistent vomiting, severe abdominal pain, and difficulty breathing. These can be signs of DHF (Dengue hemorrhagic fever) – a more severe form of dengue infection.

It can be fatal if unrecognized and not properly treated in a timely manner. With good medical management, mortality due to DHF can be less than 1%.


Go IMMEDIATELY to an emergency room or the closest health care provider if any of the following warning signs appear after the fever declines:


  • Severe abdominal pain or persistent vomiting
  • Red spots or patches on the skin
  • Bleeding from nose or gums
  • Vomiting blood
  • Black, tarry stools (faeces, excrement)
  • Drowsiness or irritability
  • Pale, cold, or clammy skin
  • Difficulty breathing



There is no specific treatment. Patients should rest, drink a lot, and avoid aspirin and ibuprofen (because of their anticoagulant properties). Fever should be controlled with acetaminophen and tepid sponge baths. Febrile patients should avoid mosquito bites to reduce the risk of further transmission. If a patient feels worse in the first 24 hours after declines the fever  (i.e develop vomiting and severe abdominal pain), they should go immediately to the hospital for evaluation.



No prophylaxis is available to prevent dengue.

No vaccine is available in the United States, (one has been licensed for use in Mexico, the Philippines, Brazil, and Thailand). Risk increases with duration of travel and disease incidence in the travel destination (such as during the rainy season and during epidemics). Travellers going to the tropics for any length of time should avoid mosquito bites by taking the following preventive measures:

  • Dengue transmitting mosquitoes typically live indoors and are often found in dark, cool places, such as in closets, under beds, behind curtains, in bathrooms, and on porches. Travellers should be advised to use insecticides to get rid of mosquitoes in these areas.
  • Wear clothing that covers the arms and legs, especially during the early morning and late afternoon, when the risk of being bitten is the highest.



for more information, visit the CDC website: