Malaria symptoms and malaria treatment
Malaria is an acute febrile illness caused by parasites transmitted to humans by infected mosquito bites. Fever, headache and chills are some of the symptoms of malaria. The treatment is based on a combination therapy based on artemisinin.
What is it ?
Malaria is the most common parasitic infection observed in the world. It is an acute febrile illness due to parasites transmitted to humans. In 2015, this disease affected 212 million people and resulted in 429,000 deaths.
Transmission of malaria
The transmission of the parasite is by the bite of a mosquito, the female anopheles. Exceptionally, it can be done by blood transfusion.
The different species of parasite involved
The infectious agent responsible is a parasite of the genus Plasmodium. Several species of Plasmodium can infect humans:
Plasmodium falciparum: represents the most frequent species and especially the most dangerous;
Plasmodium ovale: found only in black Africa;
Plasmodium vivax: not found in black Africa;
Plasmodium malariae: rarer than previous species.
Risk factors for malaria
The parasite is present in all hot and humid intertropical regions, with the exception of the French West Indies, Tahiti, Reunion and New Caledonia. Anopheles are absent from urban agglomerations in South America and Southeast Asia, as well as areas crossed by tourist routes in the Far East.
Finally, it has been described cases of malaria known as “airports” (mosquito transported in the cargo hold of an aircraft from a tropical country, a case observed in countries with a temperate climate, particularly in France).
Serious clinical manifestations observed in some cases are related to the rapid multiplication of Plasmodium falciparum in the capillaries (small blood vessels) of the brain with anoxia (significant decrease in oxygen supply).
The symptoms of malaria
It occurs 8 to 20 days after the mosquito bite.
It is manifested by a high fever accompanied by diffuse pains (headaches, body aches) and digestive disorders (nausea, diarrhea).
Signs of severity may be present at this stage:
Disorders of consciousness;
Jaundice (yellow complexion of skin and mucous membranes) early and marked;
Impairment of renal function
RHYTHM ACCESS (RECIDIVANTS)
They correspond to the evolution of a primo-invasion access that has not been processed. They can occur several months or years after the first invasion.
They evolve in a characteristic way in 3 successive phases:
Brutal onset marked by intense chills;
Follow-up of febrile peaks (body temperature 40-41 °). The patient’s condition is alarming;
And lastly abundant sweats preceding the total disappearance of the fever.
Each access lasts about 6 to 8 hours. In the absence of specific treatment, access is repeated for 3 weeks before disappearing spontaneously leaving a very tired patient.
These accesses are repeated on a third rhythm (1 st, 3 rd, 5 th, 7 th days) for Plasmodium vivax, Plasmodium ovale and Plasmodium falciparum and on a quarter rhythm (1st, 4th, 7th day) for Plasmodium malariae .
PERNICIOUS OR NEURO-MALARIA ACCESS:
It is only confined to Plasmodium falciparum and makes all the seriousness of malaria.
It represents the evolution of untreated primo-invasion access or it can occur from the outset.
The clinical signs are:
A very high fever;
Neurological disorders (disorientation, violent headaches) preceding the onset of coma;
Disorders of the function of the liver or kidney.
First-invasion access: the clinical examination is usually normal except for any signs of seriousness that the doctor will seek by a complete clinical examination (increase in the volume of the liver on abdominal palpation, disturbances of consciousness …);
Rhythmic access: comprehensive overview. Clinical signs in an evocative context allow the doctor to evoke the diagnosis;
Pernicious access: the neurological examination must be complete (depth of coma) but will not delay the start of treatment.
Complementary examinations and analyzes
The certainty of the parasitic infection is provided by the parasitology laboratory: the patient’s blood (banal blood) is spread on a slide which is then stained and examined under a microscope. The Plasmodium species is shown in the patient’s red blood cells. This is a rapid diagnosis that also determines the parasitaemia (percentage of red blood cells where the parasite is found).
Other laboratory tests show anemia (decreased hemoglobin) and thrombocytopenia (decreased platelet count in the blood).
The laboratory also provides evidence for severe access related to Plasmodium falciparum:
Hypoglycemia (decrease of glucose in the blood);
Disorders of kidney function;
Lymphopenia (decrease in number of lymphocytes in blood);
Thrombocytopenia (decrease in number of platelets in blood).
Evolution of the disease
Apart from the pernicious access, the evolution is favorable when the treatment is well conducted. In the absence of treatment, the different accesses can heal after several days of evolution.
The prognosis of pernicious access depends on the speed and quality of the treatment. Its evolution is fatal when not treated.
Artemisinin: the latter is a substance extracted from the Chinese sagebrush plant, considered by the WHO as being very effective used in combination with another antimalarial.
Resistance to antimalarial drugs
Over the years there has been resistance to antimalarial drugs (the drug is less effective due to genetic changes in the parasite).
Only Plasmodium falciparum can be resistant to chloroquine (the most common chloroquine resistance), proguanil, pyrimethamine and sulfadoxine.
Resistance to antimalarial drugs varies by geographical area.
(See also: The three zones, Conseil Supérieur d’Hygiène Publique de France).
P. vivax, P. ovale or P. malariae infection: the reference medicine is chloroquine;
P. falciparum infection:
In the absence of signs of pernicious access seriousness: if no suspicion of resistance, chloroquine. If resistance is suspected, mefloquine or halofantrine or combination pyrimethamine-sulfadoxine.
In case of pernicious access: the treatment must be undertaken urgently, at best by the hour