Epidemiology
Malaria, also known as paludism, is caused by a parasite of red blood cells, called Plasmodium. 4 varieties are responsible for the disease:
Le Paludisme ou Malaria est du à un parasite des globules rouges : le Plasmodium. 4 variétés sont responsables de la maladie :
Malaria is transmitted to humans during the bite of a female mosquito of the genus Anopheles that is infected with the parasite. It bites at night: between sunset and dawn, and it is at this time that protection must be maximised.
Approximately one hundred countries are infected with malaria, especially the poor tropical zones of Africa, Asia and Latin America. Africa is by far the worst affected. Every year, malaria kills between 1 and 3 million people, and approximately 40% of the world's population is exposed to it.
Malaria cases reported in Europe are cases of importation. Over 4,000 cases of malaria due to importation of Plasmodium falciparum are counted every year in metropolitan France.
Epidemiology
- P.falciparum :
- is the most pathogenic species, and is responsible for deadly cases. It is present in the tropical zones of Africa, Latin America and Asia, and is dominant in Africa.
- P.vivax :
- coexists with P.falciparum in many parts of the world and is present in certain temperate regions.
- P.ovale :
- the rarest species, it is mainly found in Western Africa and does not kill, but can cause relapses 4 to 5 years after the initial infection.
- P.malariae :
- has worldwide but very uneven distribution. It does not kill, but can cause relapses up to 20 years after the initial infection.
Symptoms
The symptoms are highly varied and not very characteristic. 8 to 30 days after infection, malaria begins with a fever (continuous or sporadic) with or without headaches, muscle pain, fatigue, digestive disorders, nausea, vomiting, etc.
Then, immediately after the 1st symptoms or several years afterward, depending on the species, the malarial attack occurs, characterized by typical cycles involving 3 phases :
- intense shivering, trembling and sensation of cold,
- followed by high fever > 40° (lasting approximately 3 to 4 hours),
- disappearance of the fever, cold sweat.
This malarial attack coincides with the multiplication of the parasite in the body and the rupture of red blood cells, in which the parasite has developed.
In the event of fever occurring upon returning from a country in which malaria is present, it is therefore necessary to consult a doctor immediately and tell him/her about your trip.
Complications may be observed with P.falciparum, which can sometimes be deadly. The infected red blood cells can block the blood vessels that feed the brain: this is called cerebral malaria.
Humans have no natural immunity to malaria (so you can contract the disease many times). However, in regions where the disease is highly endemic, persons who are infected very often eventually develop immunity (acquired immunity).
They can then tolerate the parasite, and are asymptomatic carriers of the disease. However, after a period without contact with the parasite, immunity disappears.
Treatment
Use of anti-malarial drugs to prevent the multiplication of the parasite in the body. Unfortunately, over the years, resistances to anti-malarials have arisen, making certain treatments ineffective.
Fortunately, new compounds have been discovered and developed by researchers and the pharmaceutical industry. The choice of treatment is based on the frequency of resistance in the area in question, and on the extent of potential side effects induced by certain compounds.
Prevention
No vaccine currently exists to prevent malaria. Protection is based on 2 mutually complementary strategies:
1. Chemoprophylaxis
As is the case with treatment, several compounds exist to prevent malaria. Unfortunately, some parasites have become resistant to them.
The choice of substance will be made based on the trip: location, season, duration, resistance, etc., as well as on the traveller: contraindications, medicinal interactions, pregnancy, children, etc.
No single preventive method provides total protection by itself, and even if appropriate treatment has been taken, it is possible to suffer an attack of malaria, sometimes with delayed onset. Therefore, in the event of even a mild fever, nausea, headache, stiffness or fatigue during the trip or in the months following the return, a doctor must be consulted immediately.
2. Prevention of mosquito bites
Prevention is mainly based on wearing ample clothing that covers the body, use of repellent products for the body and insecticide product for clothing (Moustifluid High Protection Tropical Zones and Moustifluid Lotion For Fabrics and Clothing Tropical Zones) and repellent-sprayed mosquito nets at night (Moustifluid Lotion For Fabrics and Clothing Tropical Zones).
To fight Anopheles, protection must be maximised at night, from sunset to sunrise.
Malaria and pregnancy
Malaria is a dangerous disease for pregnant women because their defence system is compromised. It can provoke severe anaemia, miscarriage, stillbirth, low birth weight, premature birth or death of the mother.
In addition, interhuman contamination is possible via the placenta, when the infection passes from the mother to the unborn child.
The most serious form of malaria is more common in pregnant women, and requires the most difficult form of treatment. Consequently, travel to areas where malaria is endemic should be completely avoided by pregnant women.
In the event of absolute necessity, measures to avoid insect bites should be maximised:
- wearing ample clothing that covers the body,
- use of appropriate repellent products (Moustifluid High Protection Tropical Zones, only the substance IR35/35 is recommended for pregnant women),
- mosquito nets,
- repellent-sprayed clothing, etc (Moustifluid Lotion For Fabrics and Clothing Tropical Zones).