Malaria
Malaria is a transmissible human disease characterized by a predominant lesion of the reticulohistiocytic system and erythrocytes, febrile attacks, anemia, enlargement of the liver and spleen.
Etiology
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- The causative agents are protozoans of the genus Plasmodium.
- Plasmodium vivax – the causative agent of three-day malaria
- Plasmodium malarias is the causative agent of four-day malaria.
- Plasmodium falciparum is the causative agent of tropical malaria.
- Plasmodium ovale – the causative agent of malaria oval (three-day type)
- Transfusion of infected blood.
Risk factors. Traveling or living in endemic regions. Epidemiology
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- Malaria is detected everywhere from 45 ° north to 40 “south latitude (but more often in the tropics and subtropics) at an altitude of 0 to 1800 m above sea level
- In states with a temperate climate, Plasmodium vivax is more often isolated, less often Plasmodium malariae
- In the tropics, Plasmodium falciparum is the main causative agent, and Plasmodium ovale is isolated only sporadically in African countries.
- Every year, in 104 endemic states, about 250 million people fall ill
- Deaths are most commonly seen in infants but have also been reported in non-immunized adults (1–2 million annually)
- The carriers are mosquitoes of the genus Anopheles. The incidence directly depends on the size of the mosquito population and the number of cases that serve as a reservoir of infection.
- In connection with the development of the tourism industry, the disease is detected in states that lie outside the natural range.
- The transmission of an infectious agent in the bulk of cases is horizontal (spread during the epidemic season is likely only through mosquitoes). Genetic Aspects
- Persons whose erythrocytes do not carry Duffy group Ag have a natural resistance to malaria pathogens (many representatives of the black race)
- Persons with a congenital deficiency of glucose-so-6-dehydrogenase have natural resistance, because parasites are unable to use the glucose monophosphate shunt as an energy source and under such conditions cannot develop in erythrocytes
- Individuals with hemoglobinopathies are also resistant to infection, because parasites are unable to multiply in erythrocytes with altered morphology, for example, in patients with sickle cell anemia
- In tropical malaria caused by Plasmodium falciparum, black-water (hemoglobinuric) fever develops, a complication of malaria that occurs after taking quinine and primaquine. It is more often observed in individuals with increased fragility of erythrocytes as a result of a hereditary defect in glucose-6-phosphate dehydrogenase, similar to Marchiafava-Micheli anemia, and also as a delayed-type hypersusceptibility reaction to quinine.
Clinical picture
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- The incubation period for malaria, depending on the type of pathogen, varies from 8 to 25 days (with a three-day period it can reach 8-14 months).
- Symptoms – fever, anemia and circulatory disorders (for all forms). Tropical malaria is the most severe.
- Fever is observed at the moment of release of parasites from destroyed erythrocytes; the intervals between manifestations of seizures depend on the biological cycle of the parasite. The onset is acute, the body temperature can reach 40-41.7 ° C (traditionally, the temperature rise is observed in the daytime), after a few hours it lytically drops to 35-36 ° C.
- Anemia is a consequence of massive lysis of red blood cells and phagocytosis of affected cells by phagocytes. Black-water fever in tropical malaria is characterized by acute massive hemolysis, hemolytic jaundice, back pain, hemoglobinuria. Much less often, and only in tropical malaria, intravascular hemolysis is observed.
- Circulatory disorders are caused by an increase in body temperature. Vasodilation leads to a decrease in BCC and blood pressure. Subsequent vasospasm, high vis-
blood bone, blockage of capillaries by erythrocyte residues lead to ischemia of organs and tissues.
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- Acute glomerulonephritis sometimes accompanies tropical (falciparum) malaria; with chronic disease caused by Plasmodium malariae, progressive renal failure may develop. Nephropathology in malaria is due to autoimmune mechanisms.
- Enlargement of the spleen and thrombocytopenia (often).
- Lesions of the digestive tract (for example, gangrenous and ulcerative changes in the intestinal mucosa, liver enlargement, fibrous pancreatitis).
Laboratory research
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- Blood test – anemia, leukopenia, thrombocytopenia, an increase in the concentrations of ALT and AST, an increase in the content of direct and indirect bilirubin, a decrease in the concentration of albumin
- Microscopy of smears for the presence of parasites. For the preparation of smears, capillary and venous blood is used. Smears are stained according to Wright or Romanovsky-Giemsa. Plasmodium species are differentiated by morphological differences. Differential Diagnosis
- Acute hepatitis
- Acute hemolytic anemia
- Acute diarrhea
- Stroke
- Pneumonia
- Acute viral infection
- Other causes of tropical splenomegaly.
Treatment:
Tactics of conducting
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- Hospitalization is recommended for patients in the acute stage and patients with tropical malaria
- In severe cases, control the likely development of complications, for example, severe anemia and kidney failure. Drug therapy – the impact on the erythrocyte forms of plasmodium (treatment of malaria).
- For malaria caused by Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium falciparum sensitive to chloroquine (chingamine), chloroquine phosphate (chloroquine, chingamine) orally.
- Adults – at the first dose of 1 g (600 mg of base), then after 6 hours – 500 mg (300 mg of base), on days 2 and 3 – 500 mg 1 r / day.
- Children – at the first dose of 10 mg / kg (not more than 500 mg), then 5 mg / kg after 6 hours, on days 2 and 3, 5 mg / kg 1 r / day.
- In uncomplicated malaria caused by Plasmodium falciparum resistant to chloroquine.
- Oral combination of quinine sulfate and tetracycline or clindamycin or sulfadoxine-pyrimethamine (Fansidar)
- Adults – quinine sulfate 650 mg 3 times a day for 3-7 days, tetracycline 250 mg 4 times a day for 7 days, clindamycin 450 mg 3 times a day for 3 days, sulfadoxine-pyrimethamine 3 tablets in one dose
- Children – quinine sulfate 3 r / day for 3-7 days, sulfadoxine pyrimethamine 1/2 tablet (up to 4 years), 1 tablet (4-8 years), 2 tablets (8-12 years) and Pregnant women – quinine sulfate 650 mg 3 r / day for 3-7 days, clindamycin 450 mg orally every 8 hours for 3 days or.
- Mefloquine or halofantrine. Adults – mefloquine 15 mg / kg orally as a single dose (no more than 1,250 mg), halofantrine 6 tablets (250 mg salt), 2 tablets every 6 hours up to 3 doses.
- In the complicated (malignant) course of malaria (parasitemia> 5%, neurological disorders or inability to take the product orally) – quinine dihydrochloride 10 mg / kg IV drip for 1-2 hours, then, or