Dengue in Portugal - CDC Travel Outbreak Notice

Updated: February 20, 2013

What Is the Current Situation?

As of February 3, 2013, 2,164 cases of dengue fever have been reported from the Portuguese island of Madeira since October 2012. There have been 78 cases of dengue reported in European travelers returning from Madeira.

At this time, CDC does not advise against travel to Madeira. However, travelers should protect themselves from mosquito bites.

What Is Dengue?

Dengue is an illness caused by a virus that is spread through mosquito bites. Symptoms include fever, headache, nausea, vomiting, rash, and pain in the eyes, joints, and muscles. Symptoms can take up to 2 weeks to develop after you are bitten by an infected mosquito but usually last one week. In severe cases, symptoms may include intense stomach pain, repeated vomiting, and bleeding from the nose or gums. See a doctor right away if you have these symptoms.

Travelers who go to tropical and subtropical regions are at risk of getting dengue. These areas include parts of the Caribbean, Central and South America , Western Pacific Islands, Australia (Queensland), Southeast Asia, and Africa . Dengue is more common in urban areas and is not usually seen at altitudes above 5,000 feet (1,500 meters). The mosquito that carries the dengue virus bites both day and night and is commonly found indoors as well as outdoors.

How Can Travelers Protect Themselves?

There is currently no vaccine or medicine to prevent dengue. Travelers can protect themselves from dengue by preventing mosquito bites.

• Prevent mosquito bites
  • Cover exposed skin by wearing long-sleeved shirts, long pants, and hats.
  • Use an appropriate insect repellent as directed
  • Use products with the following active ingredients. Higher percentages of active ingredient provide longer protection.
    • DEET
    • Picaridin (also known as KBR 3023, Bayrepel, and icaridin)
    • Oil of lemon eucalyptus (OLE) or PMD
    • IR3535 (Avon Skin So Soft Bug Guard Plus)
  • Always use insect repellent as directed.
    • If you are also using sunscreen, apply sunscreen first and insect repellent second.
    • Reapply as directed.
  • Follow package directions for using repellent on children
  • Use permethrin products on clothing and gear. Do not use permethrin directly on skin.
  • Stay and sleep in screened or air-conditioned rooms
  • Use a bed net if the area where you are sleeping is exposed to the outdoors.
• If you are bitten by mosquitoes:
  • Avoid scratching mosquito bites
  • Apply hydrocortisone cream or calamine lotion to reduce itching.
• If you feel sick and think you may have dengue:
  • Talk to your doctor or nurse as soon as possible if you develop a fever during or in the 2 weeks after travel.
  • Get lots of rest and drink plenty of liquids.
  • Take medicine to control your fever and reduce your pain. Use acetaminophen (Tylenol). Do not take medicine that contains aspirin, ibuprofen (Advil®), or naproxen (Aleve).
  • Avoid spreading the disease by preventing more mosquito bites. 
  • See a doctor right away if you have intense stomach pain, repeated vomiting, or bleeding from the nose and gums.

Clinician Information:

Early and proper diagnosis of dengue is important, as many other diseases may mimic dengue. Health care providers should consider dengue, malaria, chikungunya, and leptospirosis, depending on the itinerary and exposure, in the differential diagnosis of patients who have fever and a history of travel to tropical areas during the 2 weeks before symptom onset.

See the Clinical & Laboratory Guidance on the CDC dengue website for information about reporting dengue cases and guidance regarding dengue diagnostic testing. A serum sample should be obtained as early after the onset of fever as possible for dengue diagnostic testing. Molecular testing for DENV and immunodiagnostic testing for IgM anti-DENV should be ordered and can be obtained from commercial reference laboratories and a number of state or territorial health department laboratories. Consultation regarding management of suspect dengue cases or diagnostic testing can be obtained from:

CDC Dengue Branch
Division of Vector-Borne Diseases
National Center for Emerging and Zoonotic Infectious Diseases
1324 Calle Cañada
San Juan, Puerto Rico 00920-3860
Telephone: 787-706-2399; fax: 787-706-2496