Close

      This website requires cookies. Please accept or refuse these cookies first.
      For more info about our cookies, please read our cookies policy.

      Wanda, homepage
      Make an appointment
      Wanda for travellers

      Dengue

      Latest update: - Authors: Nele Alders, Ula Maniewski

      Dengue, also known as “break-bone fever”, is the most prevalent arbovirus. Arboviruses are viruses that are transmitted by arthropods, such as mosquitoes. 

      Dengue virus serotypes

      There are four dengue virus serotypes: DENV-1, DENV-2, DENV-3 and DENV-4. It is possible to get infected by each serotype. Recovery from an infection by one serotype is believed to provide lifelong immunity against that specific serotype. However cross-immunity to other serotypes is only partial and temporary. Subsequent infections (secondary infection) by other serotypes increases the risk of developing severe dengue.
      DENV serotypes that cause outbreaks and endemic disease vary by region and over time. Epidemiological data from India, Latin America and South-East Asia indicate that all 4 serotypes circulate in these regions, with different serotypes predominating during different periods. Co-circulation of serotypes has also been reported, usually with one serotype predominating.

      Transmission

      Dengue is transmitted to humans through the bite of an infectious female Aedes mosquito. Mosquitos become infected when they bite a person infected with the virus, once infectious the mosquito is capable of transmitting the virus during subsequent blood meals during the rest of its life. Febrile patients should avoid mosquito bites to reduce the risk of further transmission. 

      Vector

      The primary vectors are Aedes aegypti, and to a lesser extent Aedes albopictus. These mosquito species can also transmit chikungunya, yellow fever and Zika viruses. 

      Aedes aegypti is a day-time feeder, the peak biting periods are early in the morning and in the afternoon until the evening before sunset.

      They lay eggs in natural containers such as tree holes. Nowadays they are well adapted to urban environments and larval habitats are often man-made containers like buckets, discarded containers, used tyres, storm water drains etc., thus making dengue an insidious disease in densely populated urban areas. 

      Incubation period

      Dengue begins after an incubation period of four to ten days (with a range of 3 to 14 days) after the bite from an infectious mosquito.

      Symptoms

      Most dengue infections are asymptomatic. It is estimated that one in four will develop symptoms. The most common presentations is a mild to moderate flu-like illness.

      Dengue begins abruptly with symptoms like:

      • fever
      • severe headache
      • pain behind the eyes
      • muscle and joint pains
      • nausea
      • vomiting
      • swollen glands
      • rash

      It usually last two to seven days. Often, but not exclusively, a biphasic pattern is present with an initial three to four days of fever followed by improvement with a recrudescent of the fever on day five to six. Frequently a red rash, macular exanthem comparable with measles, is seen.

      There is no specific treatment available. Supportive care such as fever reducers and pain killers can be taken to control the symptoms, the best option is paracetamol. It’s advised to avoid non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin (acetylsalicylic acid) because of their anticoagulant properties.

      Severe dengue

      Approximately one in twenty patients with dengue virus disease progress to develop a severe-life threatening diseases called ‘severe dengue’. It is a potentially deadly complication due to plasma leaking, severe bleeding, and/or organ impairment.

      Severe dengue has a high risk of death when not managed appropriately, early recognition and promptly initiating intensive support therapy can reduce the risk of death.

      Severe dengue is very rare in travellers and expatriates. It can occur during infection with any of the four dengue serotypes. It is more common among infants and individuals who are infected for the second time with a different serotype (secondary dengue virus infections).

      The most widely cited hypothesis for this occurrence is antibody-dependent enhancement of disease. It occurs when non-neutralizing anti-dengue virus antibodies bind to but do not neutralize an infecting dengue virus. This virus-antibody complex allows for enhanced viral entry into host cells, specifically dendritic cells and macrophages. Once inside the cell, the virus replicates and generates higher virus titers in the blood than when anti-dengue virus antibody is not present, which results in a ‘cytokine storm’ and ultimately leading to more severe disease.

      Risk areas

      Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. There is usually no risk above an altitude of 2000 metres.

      Dengue outbreaks are occurring in many countries of the world in the Americas, Africa, the Middle East, Asia, and the Pacific Islands. Asia represents around seventy percent of the global burden of disease.

      View the map

      Prevention

      Dengue is common in Belgian travellers, but severe dengue, hospitalisation or death because of dengue is rare. Travellers at risk for dengue should be advised on:

      Additional information

      Back to top
      Give your opinion!