Dengue fever symptoms, risks and prevention as cases rise in Europe

Europe is currently battling a rise in dengue fever cases, as an invasive mosquito species has been discovered in 13 EU countries. Dengue fever can be fatal in severe cases, although it often presents mild or no symptoms.

The World Health Organisation (WHO) has issued a warning that about half of the world's population is now at risk of dengue, with an estimated 100400 million infections each year. The European Centre for Disease Prevention and Control (ECDC) suggests that climate change is creating favourable conditions for the tiger mosquito, which is believed to be spreading the disease.

Even in Paris, authorities are actively monitoring and trapping these insects. The ECDC has warned that international travel could increase the risk of more outbreaks across Europe, reports the Mirror.

READ MORE - Primary school downgraded to ‘requires improvement’ after seven years

READ MORE - Community rocked after two men injured in knife attack in Easton

But what exactly is dengue fever, how can you identify if you have it, what does it do - and how do you contract it?

Dengue fever, also known as break-bone fever, is a viral infection transmitted to humans via the bite of infected mosquitoes. It is prevalent in tropical and sub-tropical climates worldwide, primarily in urban and semi-urban areas.

Prevention and control of dengue hinge on vector control. There is no specific treatment for dengue/severe dengue, but early detection and access to appropriate medical care can significantly reduce fatality rates from severe dengue.

While most people who contract it will not show symptoms, those who do may experience high fever, headache, body aches, nausea, and rash. Most patients recover within one to two weeks.

However, in some cases, individuals develop severe dengue requiring hospital care - in extreme cases, it can be fatal. To reduce your risk of contracting dengue, avoid mosquito bites, especially during daylight hours.

What are the symptoms?

According to the World Health Organisation (WHO), most people with dengue experience mild or no symptoms and recover within one to two weeks. In rare cases, dengue can become severe and result in death.

Symptoms, if they occur, typically begin 410 days after infection and last for 27 days. Symptoms may include:

• High fever (40°C/104°F);

• Severe headache;

• Pain behind the eyes;

• Muscle and joint pains;

• Nausea;

• Vomiting;

• Swollen glands;

• Rash.

Those infected for the second time are at a higher risk of developing severe dengue.

Severe dengue symptoms often appear after the fever has subsided:

• Severe abdominal pain;

• Persistent vomiting;

• Rapid breathing;

• Bleeding gums or nose;

• Fatigue;

• Restlessness;

• Blood in vomit or stool;

• Being very thirsty;

• Pale and cold skin;

• Feeling weak.

Individuals exhibiting these severe symptoms should seek immediate medical attention. After recovery, people who have had dengue may feel fatigued for several weeks.

How can you treat it?

There is no specific treatment for dengue. The focus is on managing pain symptoms.

Most cases of dengue fever can be treated at home with pain medication. For people with severe dengue, hospitalisation is often necessary.

Acetaminophen (paracetamol) is commonly used to manage pain. Non-steroidal anti-inflammatory drugs like ibuprofen and aspirin are avoided as they can increase the risk of bleeding.

If you contract dengue, it's important to:

• Rest;

• Drink plenty of liquids;

• Use acetaminophen (paracetamol) for pain;

• Avoid non-steroidal anti-inflammatory drugs, like ibuprofen and aspirin; and

• Watch for severe symptoms and contact your doctor as soon as possible if you notice any.

So far, only one vaccine (QDenga) has been approved and licensed in certain countries. However, it's only recommended for those aged between 6 to 16 years in high transmission areas.

Several other vaccines are currently under review.

But how can you contract it?

It's transmitted through mosquito bites.

The dengue virus is passed on to humans via the bites of infected female mosquitoes, primarily the Aedes aegypti species. Other species within the Aedes genus can also act as carriers, but their contribution is usually secondary to Aedes aegypti.

However, in 2023, there was a spike in local transmission of dengue by Aedes albopictus (tiger mosquito) in Europe.

After feeding on an infected person, the virus multiplies in the mosquito's midgut before spreading to secondary tissues, including the salivary glands. Once infectious, the mosquito can transmit the virus for the rest of its life.

Human-to-mosquito transmission

Mosquitoes can become infected from people who have the dengue virus. This could be someone who has a symptomatic dengue infection, someone who is yet to show symptoms (they are pre-symptomatic), or even someone who shows no signs of illness (they are asymptomatic).

Human-to-mosquito transmission can occur up to two days before someone shows symptoms of the illness, and up to two days after the fever has subsided. Most people are viremic for about four to five days, but viremia can last as long as 12 days.

Maternal transmission

The main way the dengue virus spreads between humans is through mosquito bites. However, there's also evidence that it can be passed from a pregnant mother to her baby.

However, the chances of this happening seem to be quite low, and it seems to depend on when during the pregnancy the mother gets infected with dengue. If a mother does get dengue while she's pregnant, it could lead to her baby being born prematurely, having a low birth weight, or suffering from foetal distress.

There have also been rare cases where the virus has been transmitted through blood products, organ donations, and transfusions. It's also been found that the virus can be passed from one generation of mosquitoes to the next.