Public health advice on mosquito-borne diseases

Mosquito-borne diseases spread to people through the bites of infected mosquitoes. In the WHO European Region, these diseases include dengue, West Nile fever, chikungunya, Zika virus disease and malaria. These diseases and their symptoms range from mild and short-term to more severe conditions, and in some cases they may cause disability or death.

Mosquito-borne diseases typically thrive in warm, wet climates. However, in recent years, they have increasingly been reported in temperate regions outside the tropical zones, including across the WHO European Region.

The mosquito species that carry diseases include Anopheles, Aedes and Culex, each with hundreds of subspecies. While their geographical distribution and the risk of infection vary, all 3 can be found in many countries across the WHO European Region.

• The Anopheles mosquitoes can transmit malaria.
• The Aedes mosquitoes (some subspecies are also known as tiger mosquitoes) can transmit infections like dengue, chikungunya and Zika virus disease.
• The Culex mosquitoes can transmit the West Nile virus. 

The best way to lower your risk of mosquito-borne diseases is to protect yourself from mosquito bites by following the measures below.

• Wear light, breathable clothing that covers most of your body (such as long sleeves and pants).
• Use insect repellent on both your clothes and skin, choosing products approved by relevant authorities and following the manufacturer’s instructions.
• For children, especially very young, follow the product’s age recommendations. Adults should apply repellent on children.  
• If using sunscreen, apply it first, then wait before applying insect repellent.
• Use window and door screens to keep mosquitoes out of your house.
• Sleep in an air-conditioned room or use fans. Use mosquito nets for baby cots and carriers.

Before travelling to areas where mosquito-borne diseases are common, it’s wise to consult your local travel clinic for advice.

Mosquitoes can breed in both urban and rural settings, in clean or polluted water. Common breeding sites include pools, flowerpots, pit latrines, discarded tires collecting water and water containers with loose-fitting lids or without lids.

You can prevent mosquito breeding by:

• removing or managing sites with stagnant water, such as flowerpots, uncovered barrels, buckets, used tires and trash that collects rainwater;
• keeping water containers covered or emptying, cleaning and disinfecting them often; and

• applying safe insecticides on outdoor water containers.

Symptoms of mosquito-borne diseases may vary depending on the disease and can change throughout its progression, but common symptoms include:

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

Other symptoms can include extreme tiredness, loss of appetite, confusion and abdominal pain.

If any of these symptoms are severe or if you develop jaundice (yellowing of the eyes or skin), dark urine, bleeding from the nose or gums, blood in the stool or vomit, stiff neck, muscle weakness, tremors or seizures, seek immediate medical care and mention any recent travel history.

There is no specific treatment for mosquito-borne diseases, except for malaria. If diagnosed with malaria, follow the advice and course of treatment recommended by your health-care provider.

For the other diseases, treatment focuses on relieving the symptoms. If you experience severe symptoms, seek immediate medical care. It is also important to:

• get adequate rest;
• drink plenty of liquids;
• watch for severe symptoms;
• use paracetamol to manage pain until your health-care provider rules out dengue; and
• avoid using aspirin or ibuprofen, as they can increase the risk of bleeding in people with dengue.