Definition: what is dengue fever?
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Previously known as “tropical flu”, dengue fever is a viral infection that is spread to humans by mosquito bites.
Each year, according to the World Health Organisation (WHO), around 50 million people are contaminated, mainly in tropical and subtropical areas where it kills thousands. But it has also been raging through Europe since 2010.
The virus responsible for this infection is an arbovirus (a micro-organism passed on by insects) which is a part of the Flavivirus II genus. Nowadays it is one of the most common viruses throughout the world but there are also 4 different strains which create a high variability.
Therefore, the most difficult thing about overcoming dengue fever is the way it is sadly so effectively spread: by mosquitos. This is because these insects are the main carriers of the fever. Infected by the virus, the specimens from the Aedes genus contaminate humans by biting them and drinking their blood.
Symptoms of dengue fever
Dengue fever can appear in many different ways and can interchangeably affect babies, children and adults. Symptoms normally start to appear after 2 to 7 days of incubation, which are undoubtedly flu-like:
- high fever
- headaches
- nausea
- vomiting
- joint and muscle pains
In some cases, a skin rash can also appear similar to that of measles.
After 3 to 4 days, a brief remission is observed, but this generally comes before symptoms become more intense and the fever reappears. After about a week, the fever spontaneously changes and the patient makes a full recovery. However, it is often followed by a long resting period (about a fortnight) due to persistent fatigue. If the dengue fever is particularly crippling, it is not considered severe, unlike haemorrhagic fever.
Complications of dengue fever: haemorrhagic fever
In some cases, the classic form evolves with serious complications and becomes haemorrhagic fever. This occurs in 1% of cases in the world but is very serious and can lead to death.
Then, the first symptoms start to appear which include a persistent high fever as well as multiple haemorrhages, especially in the intestines, under the skin and in the brain. It is often necessary to go into hospital but can quickly evolve and the patient makes a full recovery.
Nevertheless, for some patients (often children under the age of 15), the infection can worsen and cause circulatory deficiencies. This is then referred to as dengue shock syndrome. This complication without an IV drip, can often lead to death.
Treating dengue fever
Currently, there is no curative treatment for dengue fever, mostly due to the huge variability of the virus and also because in most cases, the fever heals spontaneously on its own. Caring for these patients therefore essentially involves easing their symptoms. They should rest, keep hydrated and taking paracetamol based medication to ease the fever pains.
In the most severe cases, a trip to the emergency room is necessary to rehydrate patients through an IV drip or even to carry out a transfusion if necessary. However nowadays, there is no preventative treatment or vaccine against dengue fever. To avoid this infection, prevention essentially relies on fighting against mosquitos. The aim is to avoid their bites by using mosquito nets and repellents.
On a larger scale, the objective is to reduce the population of insects by eliminating their breeding grounds and possible areas where they spread this infection such as stagnant water reserves. Over these last years, another strategy has also been put into place, especially in Brazil, to create genetically modified male mosquitos whose offspring will not reach adulthood.
