Beginning >> Diseases >> Infectious >> Malaria


Table of contents
Clinic of malaria
Diagnosis of malaria
Treatment and prevention

Malaria — the acute infectious disease which is characterized by periodic attacks of fever (paroxysms), increase in the sizes of a liver and spleen, anemia.

Etiology. The causative agent of malaria are plasmodiums. The disease causes 4 look in the person a plasmodium: P. vivax, P. falciparum, P. malariae, P. ovale.

Life cycle of malarial parasites is carried out by asexual reproduction in a human body (schizogony) and sexual development in an organism of a mosquito (sporogony). At a sting of the infected mosquito sporozoita get to a human body. In the lympho-and hematogenous way they are brought in liver cells where as a result of reproduction fabric merozoites which get into blood erythrocytes are formed. Here they turn into schizonts which repeatedly are divided into merozoites. At destruction of erythrocytes merozoites get to blood and again are implemented into erythrocytes. The new cycle of asexual reproduction begins. After 2 — 3 cycles of a schizogony the part of merozoites is transformed to sex cells — gametes — female and man's which mosquitoes catch. Duration of an erythrocyte cycle of a schizogony depends on a type of a plasmodium — 48 and 72 h.

a) малярийный комар     b)  немалярийный комар

Landing of malarial and not malarial mosquitoes 

Sexual development occurs in an organism of a mosquito. With blood of the patient of a gamete come to a stomach of a mosquito. Man's sex cells connect to female and turn into zygotes, then ookinetes which are implemented into a stomach wall where the oocysts containing sporozoita are formed. Oocysts are broken off, and sporozoita get to a perigastrium, then to sialadens of a mosquito.

Epidemiology. An infection source — the patient and a parazitonositel, the infection mechanism — transmissible. The activator is transferred by females of a mosquito of a sort anofeles. Isolated cases of a disease of malaria in Russia mainly brought in (from the countries of Southeast Asia and especially Africa).

Pathogeny. Development of malarial parasites in fabrics is not shown by clinical symptoms. The disease is connected with an erythrocyte schizogony, destruction of erythrocytes and an exit in blood of a large number of merozoites, a foreign protein and decomposition products of cells. The first cycles of a schizogony cause a sensitization to a foreign protein, the subsequent — giperergichesky reaction like the acute anaphylaxis which is clinically shown paroxysms.

Destruction of the struck erythrocytes, their hemolysis as a result of formation of autoantibodies, and also lead increases of activity of reticuloendothelial system and oppression of a haemo cytopoiesis to development of anemia, a leukopenia, thrombocytopenia. Development of malignant forms is connected with disturbance of microcirculation in brain vessels.

"Loasis   Marseilles fever"