Key points about malaria
- Malaria is a parasitic disease transmitted by the bite of infected mosquitoes, found mainly in tropical regions.
- It can be serious, even fatal, particularly in young children, pregnant women and in the absence of prompt treatment.
- Any fever upon returning from a trip to a tropical area should raise suspicion of malaria.
- Effective treatments exist and the disease can be prevented by measures against mosquito bites and appropriate prevention before travel.
What is malaria?
Malaria is a potentially fatal parasitic infectious disease caused by protozoa of the genus PlasmodiumIt is prevalent in tropical areas, transmitted to humans by the bite of female mosquitoes of the genus Anopheles infected by the parasite. Five species of Plasmodium are responsible for human infections, including Plasmodium falciparum, which is responsible for the most severe forms and the majority of deaths, and P. vivax, P. ovale, P malariae et P. knowlesiAfter the infectious bite, the parasite first multiplies in the liver, then invades red blood cells, the phase responsible for clinical manifestations. Some species (P. vivax et P. ovale) can persist in a latent state in the liver and cause late relapses in the absence of radical treatment.
Malaria worldwide
Malaria remains a major global public health problem, despite the progress made in recent decades. According to international estimates, the disease is responsible for each year several hundred million cases and several hundred thousand deaths worldwide (282 million cases and 610,000 deaths in 2024, approximately 9 million more cases than the previous year). Transmission is mainly concentrated in tropical and subtropical regions. Sub-Saharan Africa supports the overwhelming majority of the global load, with approximately 95% of cases and deathsmainly related to Plasmodium falciparumChildren under five and pregnant women are the most vulnerable populations. Malaria is also present in South East Asia (Singapore, Indonesia, Malaysia, Thailand, Philippines, Brunei, Vietnam, Laos, Burma, Cambodia), South Asia, Latin America and in certain regions of Middle-East and PeacefulIn these areas, P. vivax is more frequent and responsible for generally less severe but often recurring forms. In non-endemic countries, malaria is observed in the form of imported cases, primarily among travelers, migrants, or people visiting family in endemic areas. It constitutes the leading cause of fever upon return from tropical travelThe fight against malaria is currently facing several major challenges, including the emergence of resistance to antimalarial drugs, the mosquito resistance to insecticides, political instability in certain endemic areas and the effects of climate change on vector distribution.
What are the symptoms of malaria?
Clinical manifestations of malaria generally appear after an incubation period of 7 to 30 days, but may be later depending on the species involved and whether chemoprophylaxis has been administered. Uncomplicated malaria most often manifests as high fever, sometimes preceded by chills and followed by sweating, associated with headache, muscle aches, a intense fatigue and Team digestive disorders such as nausea, vomiting, or diarrhea. Certain forms, particularly those due to Plasmodium falciparumcan quickly evolve into a severe malariaSevere malaria is characterized by neurological symptoms (altered consciousness, seizures, coma), severe anemia, respiratory distress, hypoglycemia, acute renal failure, or shock. It constitutes a life-threatening medical emergency.
Malaria diagnosis
The possibility of malaria should be considered. in the event of any fever occurring upon return from an endemic arearegardless of the time elapsed since return. It relies on detecting the parasite in the blood through parasitological examinations. tick drop, associated with blood smearThis constitutes the reference method, allowing both confirmation of the diagnosis and identification of the species of Plasmodium and to assess parasitemia. rapid diagnostic tests These tests can be used as a first-line approach, particularly in emergency situations, but they do not replace microscopic examination. Further laboratory tests are often necessary to assess the severity and guide treatment.
What are the treatments for malaria?
Malaria treatment depends on the identified species, the geographic area of contamination, the severity of the infection, and the patient's underlying health conditions. Uncomplicated cases are treated with artemisinin-based therapeutic combinations or by other effective antimalarial drugs depending on local resistance levels. Infections with P. vivax et P. ovale require, in addition, a radical treatment aiming to eliminate dormant hepatic forms, after verifying the absence of G6PD deficiency. Severe malaria requires emergency hospitalization and treatment by intravenous artesunatefollowed by oral administration, combined with close clinical and biological monitoring.
Malaria prevention
Malaria prevention relies on a combined approach. mosquito bite control constitutes a key pillar, including the use of insecticide-treated bed nets, skin repellents, protective clothing, and environmental vector control measures. For travelers going to endemic areas, a Malaria chemoprophylaxis adapted to the destination is recommended, starting before departure and continuing after return (as parasites can still appear in the liver during this period). Since this treatment does not provide 100% protection, adherence to barrier measures remains essential. At the community level, prevention strategies include improving access to early diagnosis and treatment, large-scale vector control, and, more recently, the deployment of malaria vaccines with partial effectiveness in some endemic countries, in addition to other control measures.
Malaria research at the Pasteur Institute of Lille
Two laboratories are working on malaria within the Lille Infection and Immunity Center (CNRS UMR9017, INSERM U1019, University of Lille, IPL). The team of Dr. Sylviane Pied work on cerebral malaria. The researchers' objective is to identify the mechanisms in the brain that lead to the development of the disease. Clinical data (field studies) and preclinical models help identify biomarkers and/or potential therapeutic avenues. Dr.'s team Jamal Khalife seeks to characterize new antimalarial drugs. Certain parasitic enzymes are targeted, notably phosphatases.
FAQ
It is a parasitic disease caused by the protozoan Plasmodium, transmitted by the bite of an infected Anopheles mosquito.
Irregular fever, digestive problems, headaches, muscle pain, then bouts of fever with chills and sweats.
Yes, especially with Plasmodium falciparum, which can lead to severe, sometimes fatal complications.
Through blood analysis which detects the parasite or its antigens.
Yes, there are several effective antimalarial treatments, which should be started quickly.
Limit mosquito bites (mosquito nets, repellents) and follow appropriate chemoprophylaxis.
No, but imported cases do occur among travelers returning from endemic areas.
