What is dengue fever?
The dengue virus causes dengue fever (DF), also known as breakbone fever, dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). DHF and DSS are two severe variants of dengue fever. The virus is transmitted by mosquitoes that bite during the day.
Dengue fever symptoms
The incubation period for the dengue virus is between three and 14 days (generally between four and seven days) following a bite by an infected mosquito. Most people who are infected with the dengue virus do not develop any symptoms. Non-severe dengue virus infections are characterised by the following symptoms:
- Acute fever (up to 41°C) with chills
- Headache, particularly behind the eyes
- Muscle and joint ache
- Sore throat
People with non-severe dengue virus infections generally recover within a few days or a week. Dengue fever is a disease you can contract more than once. In a small percentage of cases, infection with the dengue virus will develop into severe dengue fever with complications, such as dengue haemorrhagic fever (DHF) or dengue shock syndrome (DSS). If left untreated, such complications may be fatal.
How to prevent being infected
The dengue virus is spread through the bite of infected Aedes mosquitoes, particularly yellow fever mosquitoes (Aedes aegypti) and Asian tiger mosquitoes (Aedes albopictus). These mosquitoes are also known to transmit other viruses, such as the chikungunya and Zika viruses.
Vaccines against the dengue virus are not yet available in the Netherlands. Dengue fever prevention should focus first and foremost on preventing getting bitten by mosquitoes, particularly in the early morning and late afternoon, when Aedes mosquitoes are active. You can minimise your chances of getting infected by wearing clothes that cover your entire body and by applying a mosquito repellent containing diethyltoluamide (DEET). Travellers are also advised to sleep under a mosquito net impregnated with a mosquito repellent.
How common is dengue fever?
Dengue fever is particularly common in tropical and subtropical regions, including Africa, South East Asia, Central and South America and the Caribbean. The number of people infected with the dengue virus has risen very quickly in recent decades. Each year, some 90 million people across the globe are infected with the dengue virus and develop symptoms. Some 500,000 of them (mostly children) suffer severe dengue fever. . Several dozens of dengue virus infections are reported each year in the Caribbean Netherlands.
In the European (or continental) Netherlands, dengue fever only occurs when it is imported from other countries. Since dengue fever is becoming more and more common across the globe, overseas travellers are increasingly likely to return home with a dengue virus infection. According to the weekly counts of virological notifications, there are approximately 150 dengue virus infections annually (Figure 1).
[Number of positive tests] Figure 1 Number of positive dengue virus tests by week of laboratory diagnosis, according to the weekly counts of virological notifications from the European Netherlands; Week 1, 2010, to Week 45, 2016.
1. WHO World Health Organization. Dengue and Severe Dengue: Fact Sheet. Updated July 2016.