Malaria (malaria)

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What is it about ?

Malaria is an infectious disease caused by the Plasmodium parasite. This parasite is transmitted to humans through the bite of a very specific mosquito: the anopheles.

Malaria is only present in places where this mosquito is also present, especially in the tropics and subtropics. Sometimes cases do occur in our area, when these mosquitoes arrive here by plane or by boat. The risk of being bitten is greatest in rural areas of Africa. The mosquito spreads in stagnant water, ponds, hollow logs, lakes, etc. The risk of infection is much lower in large cities and at altitudes above 1,500 meters.

There are four species of Plasmodium parasites: P. falciparum, P. vivax, P. ovale and P. malariae. P. falciparum is the most dangerous. The infection progresses into a serious illness. In addition, many of these parasites are already resistant to commonly used drugs.

What is its frequency?

  • Malaria is one of the most common infections on the planet. There are more than 200 million cases of malaria each year, and it is estimated that the disease kills more than 400,000 per year, mostly among children in Africa.
  • Most malaria cases and deaths are in tropical Africa.
  • Malaria has been much less common in recent years.
  • The most common form of the disease, caused by P. falciparum, is responsible for around 90% of malaria deaths worldwide.

How to recognize it?

The incubation period, i.e. the interval between the mosquito bite and the appearance of the first symptoms, varies from 10 days to 1 month. So you may have been home for a while before you got sick.

The characteristic symptoms are flare-ups of fever, with alternating high peaks and days without fever. The fever is often accompanied by chills. There may also be headaches and stomach aches and aches in the muscles.

The parasite multiplies in red blood cells and destroys them. This causes increasing anemia accompanied by fatigue, pallor, diarrhea, and sometimes jaundice and confusion.

Brain damage (cerebral malaria), characterized by rapid loss of consciousness or even coma, is a serious complication that mainly affects children. Although reversible after treatment, remaining lesions, such as epilepsy, are common. Other possible complications are respiratory distress, kidney failure, and shock.

There are forms of malaria in which the parasites are present, but asleep, in the liver. They can reactivate after months or even years and trigger a malaria attack.

How is the diagnosis made?

Anyone who has traveled to an area affected by malaria and has a fever is suspected of being infected with malaria.

Since the parasite is found in the blood, the diagnosis is made on the basis of a blood test. Just prick the tip of your finger to collect two small drops of blood. One drop is used for a blood smear, the other for a thick drop. Both are stained in the laboratory and examined under a microscope. This method allows you to see the parasite directly. The blood sample should preferably be taken during an outbreak of fever. If necessary, the examination will be repeated up to three or four times, because the fact of not seeing a parasite in the blood (negative result) does not allow to exclude malaria with certainty.

What can you do ?

The main thing you can do is prevent mosquitoes from biting you. It is after dark that they are most rampant. Wear light-colored clothing that covers your arms and legs (long sleeves, long pants or long skirts).

On the areas of your skin that are uncovered, apply a DEET-based repellent (20 to 50%). The dosage should ideally be limited to 20-30% in children and pregnant women. DEET (20-30%) only offers 4-6 hours of protection and should therefore be reapplied regularly. At the higher dosage, DEET (40-50%) protects for 8 hours, but that is not enough to last overnight.

To sleep, therefore, use a mosquito net impregnated with permethrin. Make sure that the bottom of the canvas is well wedged under the mattress. This measure alone reduces the risk of being bitten by a mosquito by 80 to 90%.

What can your doctor do?

If you are going to an area affected by malaria, your doctor will prescribe medicine for prevention. They will decide which medicine is best for you. It is therefore entirely possible that you will not take the same treatment as your traveling companions. From 40 kg, the adult dose should be administered. For a weight less than 40 kg, the dose should be calculated based on weight.

There are three types of drugs on the market:

  • The combination of atovaquone and proguanil; take 1 tablet per day from the day before departure until one week after return.
  • Doxyxycline; 1 tablet per day from the day before departure until one month after return. This drug increases sensitivity to sunlight, so be careful in tropical countries, protect yourself from the sun properly.
  • Mefloquine; 1 tablet per week, from 2 to 4 weeks before departure until one month after return. People with mental health problems or who have had convulsions in the past cannot take this product. It is especially important to start treatment on time, in order to quickly detect possible side effects (psychic).

There is no perfect protection against malaria. So if you have a fever after you return, always see your doctor.
If you have contracted malaria despite all precautions, your doctor will start treatment. If your blood test shows that more than 5% of your red blood cells are infected, if you are vomiting or if you are seriously ill, you will be treated in hospital. Otherwise, home treatment will suffice.

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