Malaria

Malaria is an acute protozoal disease characterized by febrile attacks, anemia, enlargement of the liver and spleen. Relapses are possible. The source of infection is only a person who has malaria, or a gamete carrier. Infection is transmitted by various types of mosquitoes.

Etiology, pathogenesis. Malaria of a person is caused by 4 types of pathogens; Plasmodium falciparum is the causative agent of tropical malaria, R. vivax is the causative agent of the three-day malaria (vivax malaria), P. ovale is the causative agent of oval malaria and R. malariae is the causative agent of the four-day malaria. Plasmodium malaria perform a complex cycle of development in the body of the vertebrate host (tissue and erythrocytic schizogony) and in the body of a mosquito-carrier (sporogony). When infecting during a mosquito bite, sporozoites penetrate the body, which turn into liver cells into tissue schizonts. They repeatedly divide and form a large number (up to 50,000 from each schizon) of tissue merozoites. The duration of the pre-erythrocyte cycle is 6-9 days. Then the parasites penetrate into the red blood cells, and the spectrocytic schizogony begins. The duration of schizogonia in pathogens of four-day malaria is 72 hours, the rest - 48 hours. Of great importance is the drug resistance of the causative agent of tropical malaria. In some countries of Southeast Asia, more than half of strains of tropical malaria pathogens are resistant to hingamine (chloroquine, delagil), as well as to chloridine, acrichin, quinine.

Diseases caused by drug-resistant strains often take a long (more than 50%) and malignant (3-5%) course. Drug resistance of the causative agents of tropical malaria is also observed in other regions. The pre-erythrocyte cycle of parasite development is not accompanied by clinical manifestations. The onset of the attack coincides with the moment of mass destruction of the affected erythrocytes and the release of the parasite into the blood. The attack is a kind of reaction to the foreign protein entering the blood. The destruction of erythrocytes leads to anemia. Immunity with malaria develops only with respect to the homologous form of plasmodia.

Symptoms, course. The incubation period for tropical malaria lasts 10-14 days, with a three-day period with a short incubation of -10-14 days, with a length of 8-14 months, with a four-day incubation period of 20-25 days. At the onset of the disease, fever may be of the wrong type (initial fever), and only after a few days the correct alternation of seizures is established. During the attack, there are periods of chills, heat and sweat. Attacks occur usually in the morning with maximum temperature in the first half of the day (with oval-malaria attacks begin in the evening after 18-20 hours). Chills come suddenly and happen to be "terrific." Its duration is 1.5-2 hours. The duration of the entire attack with a three-day malaria and oval malaria is 6-8 hours, four-day 12-24 hours, with tropical malaria the attack is prolonged, and the period of apyrexia is so short that it can be detected only with thermometry through Every 3 hours. The period of chills is replaced by heat, and with the onset of a drop in temperature, the patient begins to sweat profusely. His health is improving rapidly, he calms down and often falls asleep. During the period of apyrexia, the patient's well-being remains good, often he keeps working. With a three-day, tropical and oval-malaria attacks are repeated every other day, and with a four-day - after 2 days. Fever during attacks usually reaches 40 ° C and above, after the first 2-3 attacks there is a pronounced enlargement of the liver and especially of the spleen, it is painful on palpation, often a herpetic rash, as a result of the eradication of the erythrocytes there is pallor and icteric staining of the skin. Antiparasitic treatment duration of three-day malaria (with the exception of reinfection) reaches 2-3 years, tropical - up to a year and four days - up to 20 years or more.

Complications: malarial coma, rupture of the spleen, hemoglobinuria fever. For the diagnosis, blood change is important - hypochromic anemia, poikilocytosis, anisocytosis, an increase in the number of reticulocytes, leukopenia, an increase in ESR. It is necessary to differentiate from those diseases in which a paroxysmal increase in body temperature (sepsis, leptospirosis, brucellosis, visceral leishmaniasis) is possible. Evidence is the detection of malarial plasmodia in the blood. Smears and a thick drop are taken before the antimalarial treatment begins.

Treatment. With tropical malaria, appoint hingamin (delagil, chloroquine): on day 1 of 1 g and after 6 hours, another 0.5 g of the drug, then within 4 days of 0.5 g / day. In the treatment of three- and four-day malaria, a three-day course of treatment with hingamine is first conducted: on day 1, 0.5 g is given twice a day, on the 2 nd and 3 rd day - 0.5 g at one time. This course stops the attacks of malaria, but does not affect the tissue forms of the parasite. For radical treatment immediately after the end of hingamin treatment, a 10-day course of treatment with primaquine (0.027 g / day) or quinocide (0.03 g / day) is carried out. For the treatment of tropical malaria caused by drug-resistant plasmodium, quinine sulfate can be used at 0.65 g 3 times daily for 10 days in combination with sulfapyridazine: on day 1, 1 g, in the following 4 days, 0.5 g The combination of hingamine is effective (on the 1st day, 0.5 g 2 times a day, for the next 3-4 days, 0.5 g / day) with sulfapiridazine (day 1 1 g, the next 4 days 0.5 G / day). Use and other drugs. Treatment of a malarial coma is better to start with IV droplet (60 drops per 1 minute) administration of quinine dihydrochloride at a dose of 0.65 g in 250-500 ml of isotonic sodium chloride solution. Infusion can be repeated after 8 hours. The daily dose should not exceed 2 g. Also use 5% solution of deligil (available in ampoules of 5 ml) 10 ml every 6-8 hours, but not more than 30 ml / day. In severe forms, pathogenetic treatment is also carried out. Assign glucocorticoids (prednisolone 30 mg 3 times a day), antihistamines, infusion therapy, etc.

The prognosis for uncomplicated forms of malaria is favorable. With rupture of the spleen and malarial coma, lethal outcomes are not uncommon.

Prevention. Destruction of mosquito vectors, protection of people from mosquito bites (use of repellents, nets). Persons leaving for malaria endemic areas undergo chemoprophylaxis (hingamine 0.25 g 2 times and a week). The drug is prescribed 3 days before arrival in the hearth and continue to take within 4-6 weeks after leaving. After malaria it is carried out dispensary observation in accordance with the instructions.