Fever after travel

• Take a working thermometer and paracetamol (for example Dafalgan® or Panadol®).
• Take your malaria prevention medicine or your standby emergency treatment for malaria, if it has been prescribed for you.
• Write down your travel dates and the regions you visit.
• Protect yourself from mosquitoes day and night (see our leaflet on mosquitoes).

In a malaria area, see a doctor or go to a clinic immediately. Ask for a malaria test, if possible within 24 hours, at the latest within 48 hours.

Have you been given a standby emergency treatment for malaria? Take it only if no test is possible and the fever lasts more than 24 hours, following the instructions you were given. Then see a doctor as soon as possible.

If you are taking preventive treatment, finish the full course, even after you return.

For 1 year after you return, any fever above 37.5 °C is an emergency. See a doctor the same day: your own doctor, a travel medicine centre or the emergency department. Do not wait until the next day.

Malaria appears at the earliest 7 days after arriving in the area. It most often occurs in the first 3 months, rarely after more than a year. Preventive treatment protects well, but not 100%.

Pregnant women, young children, older people and people with chronic illnesses have a higher risk of complications. In an older person, malaria can show up as confusion.

Malaria is caused by a microscopic parasite spread by certain mosquitoes, in the evening and at night. It first multiplies in the liver, without any signs: hence the delay of at least 7 days. Then it enters the red blood cells and destroys them: the fever begins. The most dangerous form can reach the brain in a short time.

At the start, the blood test may not yet find the parasite: this is why it is sometimes repeated over the following days.

Other diseases cause fever, such as dengue, which is also found outside malaria areas. It is caused by a virus spread by mosquitoes that bite mainly during the day. Signs start 4 to 10 days after the bite. Most cases get better on their own, but severe forms often occur when the fever goes down. Do you have a fever within 3 months of your return? See a doctor and mention your trip.

Say from the start that you have travelled, with:

• the countries and regions visited, and your departure and return dates;
• your malaria preventive treatment: which one, and whether you took it to the end or not;
• your travel vaccines;
• swimming in fresh water, a tick bite or contact with an animal;
• unprotected sex;
• the medicines you took while travelling, including any standby emergency treatment for malaria.

Paracetamol (Dafalgan®, Panadol®) brings the fever down, but does not treat the cause: still see a doctor.

Avoid aspirin and anti-inflammatories such as ibuprofen until dengue has been ruled out: dengue can cause bleeding, and aspirin increases this risk. Do you take aspirin every day for another condition? Do not stop it without medical advice.

No antibiotics without medical advice: they do not replace the malaria test.

Call 144 if the fever comes with any of these signs:

• confusion, unusual drowsiness or seizures;
• difficulty breathing;
• bleeding from the nose or gums, blood in vomit or stools;
• repeated vomiting, or being unable to drink or keep your medicines down;
• severe stomach pain;
• yellow skin or yellow whites of the eyes;
• red or purple spots on the skin.

Without these signs, see a doctor the same day. Stay alert for 2 days after the fever ends: with dengue, serious signs often appear 1 to 2 days after the fever goes down.