Dengue Fever

Updated: April 28, 2008

• About Dengue
• Transmission
• Geographic Distribution
• Recommendations for travellers
• Monitor your health
• As a reminder...
• Additional information

 

The Public Health Agency of Canada (PHAC) reminds travellers to protect themselves from mosquito bites when traveling to areas where dengue disease may occur.  Dengue disease continues to spread with large outbreaks presently occurring in many countries. There is no vaccine or medication that protects against dengue.

About Dengue

Dengue disease is the most common mosquito-borne disease that is transmitted to humans. While people recover from most dengue infections, some cases can be more severe and potentially deadly.

The disease can present itself in two forms, although the distinction between the two forms is not always clear:

• Dengue fever (DF) begins with the sudden onset of fever, headache, joint pain and muscle aches, pain behind the eyes and a faint rash. The fever usually lasts from three to five days, and rarely more than seven days.
• Dengue haemorrhagic fever (DHF), a more severe and potentially-deadly form of the disease is characterized by fever, loss of appetite, vomiting, intense abdominal pain, shock and bleeding from the nose or under the skin.  

Transmission

The dengue virus is transmitted to humans by dengue-infected day-time biting (Aedes) mosquitoes. This mosquito species is most often found in or near homes in urban and surrounding areas. While outbreaks can occur at any time, the risk of dengue disease increases when mosquito populations increase (e.g. during and immediately following rainy seasons, flooding).

Geographic Distribution

Dengue disease occurs in tropical and subtropical areas and has been reported in over 100 countries in the Caribbean, South, Central and North America, Africa, the Pacific Islands, Hawaii, Asia and Australia. For a map outlining where there is a risk of dengue transmission, please see Figure 1 : Dengue Transmission Risk reproduced from the World Health Organization's: International and Travel Health Publication.

• For additional information on dengue please see PHAC's Disease Information Backgrounder on Dengue Fever

Figure 1:  Dengue Transmission Risk
Please note that the term “vector” in this map means the type of mosquito that can transmit the dengue virus.

Recommendations to travellers

PHAC recommends the following personal-protective measures to avoid mosquito bites:  

• Apply insect repellent to exposed skin. Use DEET-based products.  Remember to apply carefully:
  • Do not apply to cuts, abrasions or irritated skin;
  • Do not spray repellent directly on the face;
  • Wash hands after application, to avoid contact with lips and eyes; and,
  • Do not use DEET and sunscreen combination products.  If application of sunscreen and DEET is required, apply the sunscreen first and let it soak into the skin for about 20 minutes before applying DEET.
• Cover up. The less exposed skin you have, the less likely you are to be bitten. Wear light-coloured, long-sleeved shirts and long pants.
• Use mosquito netting treated with insecticide.  This should be considered especially in playpens, cribs or strollers to protect babies under six months;
• Consider your accommodations. When possible, remain in well-screened or completely enclosed, air-conditioned areas.

For more detailed information on protecting yourself and your family against mosquito bites, refer to PHAC's Statement on Personal Protective Measures to Prevent Arthropod Bites - Update.

Monitor your health

Upon your return to Canada, if you develop any fever that is associated with skin rash, bleeding or easy bruising, you should seek immediate medical attention and inform your personal health care provider, without being asked, that you have been traveling or living in an area where dengue disease may occur and what, if any, treatment you have received.

As a reminder…

PHAC strongly recommends that you consult a health care provider or visit a travel health clinic at least six weeks prior to international travel, regardless of your destination.  Meeting with a health care provider will help you understand your individual health needs and safety risks. The health care provider can suggest steps to take to prevent illness and injury while traveling and recommend appropriate vaccinations and preventative medications.

Travellers who get sick while traveling or become sick after returning to Canada should inform their health care provider.  Without being asked, travellers should tell their health care provider where they have been and what, if any, treatment or medical care they received while traveling (e.g., blood transfusions, injections, dental care, and surgery).

• Know before you go!
  General travel health advice

• Food and Water Precautions
  PHAC strongly recommends key principles regarding food and water precautions to minimize the risk of exposure to disease.

Additional information:

• Information Sheet on Dengue Fever for the Canadian Traveler by the Public Health Agency of Canada Disease Information Backgrounder on Dengue Fever

• Committee to Advise on Tropical Medicine and Travel's “Statement on Personal Protective Measures to Prevent Arthropod Bites - Update”

• World Health Organization: Dengue Page