It is widespread in warm and humid regions with an average annual temperature of 16 ° C and above, also found in more temperate climate zones, and entirely absent in the polar regions. The disease causes serious economic damage to countries with tropical and subtropical climates, leading to all diseases as the main cause of disability and mortality.
What it is?
Malaria (Italian Middle Ages. mala aria - «bad air," formerly known as "ague") - a group of vector-borne infectious disease transmitted by mosquitoes to man bites genus females Anopheles ( «Anopheles mosquitoes") and accompanied by fever, chills, splenomegaly (enlargement of spleen size), hepatomegaly (liver enlargement sizes) anemia. Characterized by a chronic relapsing course. Called parasitic protists genus Plasmodium (80-90% of cases - Plasmodium falciparum).
At the beginning of the XXI century disease was 350-500 million cases per year, of which 1,3-3 million fatal. It was expected that mortality will double over the next 20 years. According to the latest WHO estimates, in the year takes place from 124 to 283 million cases of infection with malaria parasites and from 367 to 755 000 deaths from the disease. From 2000 to 2013, global indicators on malaria mortality declined by 47% in the WHO African Region - 54%.
85-90% of the infections occur in sub-Saharan Africa, the vast majority of infected children under the age of 5 years.
How do you get?
Malaria is caused by Plasmodium falciparum. It belongs to a class of protozoa. Causal agents may be 5 species of plasmodia (although naturally there are more than 60 species):
- Plasmodium vivax - Pathogen three-day malaria. About 20% of the world's cases. The disease is named so because fever, typically occurs every 48 hours (e.g., number 1 had a fever, 2 - outlet 3 - symptoms again). It is caused by plasmodium vivax in terms of reproduction of red blood cells. At the beginning of the disease the temperature is kept constant, and there are also attacks a day, and two per day. seizure duration is about 1-2 hours. Medium-heavy appearance plazmodioza. Relapse is possible after 3-5 years;
- Plasmodium ovale - Same as plasmodium vivax, is a three-day malaria. Rare view;
- Plasmodium falciparum - the most common parasite that causes about 80-85% of cases of disease. This species of Plasmodium cause the most severe form of the disease - falciparum malaria. The disease develops rapidly, frequent cases of death, at the wrong diagnosis and delayed treatment. Often it proceeds with complications. High mortality rates, almost all malaria deaths occur in this infection Plasmodium. The temperature usually is constant, rarely gallops. Big set of symptoms characterized by the fact that P. falciparum develops in the capillaries of the internal organs, delaying their blood supply, which leads to their pathology, and the manifestation of the symptoms associated with them. Relapse is possible after 1-2 years of healing;
- Plasmodium malariae - Pathogen four-day malaria. Seizures occur every 72 hours (1 - fever, 2.3 - Output, 4 - again fever) on the fourth day. seizure duration 8-10 hours. The weakest and rare species of malaria. Relapse is possible after 10 or more years;
- Plasmodium knowlesi - A new species of malaria. Preferentially infects macaque monkeys only found in Southeast Asia, but they can also be infected persons. In some parts of Southeast Asia, about 70% of cases of infection. Disease-free form of malaria. Mortality was low (2%).
In endemic countries, there is often mixed infection. It is characterized by the simultaneous infection of several species of parasites. When parasitological study they detected in the blood.
The life cycle of malaria parasites involves a succession of several steps. Thus there is a change of owners. In step schizogony pathogens are in humans. This asexual stage of development, it is replaced by step sporogonic. It is characterized by sexual development and takes place in the body of the female mosquito, which is a vector of infection. Causal mosquitoes are Anopheles genus.
Penetration of malaria parasites in the human body can occur at different stages in different ways:
- When the mosquito bites infection occurs on sporozontnoy step. Penetrated Plasmodium 15-45 minutes are in the liver, where their intensive reproduction begins.
- Penetration plasmodia erythrocytic cycle shizontnoy step occurs directly into the bloodstream, bypassing the liver. This path is realized with the introduction of blood or the use of unsterile syringes that can be infected plasmodia. At this stage he gets from mother to child in utero (vertical way of infection). This is a risk for pregnant malaria.
In typical cases plasmodia division caught in the body by the bite of the mosquito, in the liver. Their numbers multiplied. At this time there are no clinical symptoms (incubation period). The duration of this step varies depending on the type of agent. Minimum it in P. Falciparum (6 to 8 days) and a maximum at R.malariae (14-16 days).
Malaria on the lips
Malaria appears on the lips in the form of small bubble size, located close to each other and filled with a transparent liquid. The cause of these lesions on the skin is a herpes simplex virus of the first type. Therefore, the use of "malaria" term for this phenomenon is not correct.
Also among the vulgar signs of herpes virus on the lips of such terms as "cold" or "fever on the lips." The disease is manifested by local symptoms, which develop according to a certain scheme. In addition to local symptoms of patients can be confusing and some of the common symptoms of this disease.
Symptoms of malaria in humans
The characteristic symptoms of malaria include fever, chills, joint pain, vomiting, decrease in hemoglobin in the blood, detection of hemoglobin in the urine, seizures. In some cases, patients report a tingling of the skin, the symptom is particularly common in malaria caused by P. Falciparum. On examination, the doctor notes the enlargement of the spleen, the patient is very worried about a severe headache, impaired cerebral blood supply. Malaria can end with a lethal outcome from it most strongly affects children and pregnant women.
Accurate diagnosis is made after a blood test for the presence of pathogens, which are taken two stroke - "thick drop" and a thin smear. The drop is possible to analyze a greater volume of blood, and therefore this analysis is considered to be more sensitive, but it only allows you to detect the presence of plasmodium. To determine the type of pathogen requires a thin smear, wherein the parasite is best seen. Accurate diagnosis microscopic examination of blood is not always possible to determine, as in a smear immature forms of different species of the pathogen is difficult to distinguish from each other. In the analysis, it is recommended to learn a few parasites that are different maturation stages.
By modern methods of study include special diagnostic tests, which are based on immunochemical reactions. This study is among the most rapid (5-15 minutes), accurate and at the same time the most expensive method.
complications
In frail or untreated patients as well as the following complications can develop in the treatment of errors:
- malarial coma;
- edema syndrome;
- extensive bleeding (haemorrhage);
- different versions of psychosis;
- renal and hepatic insufficiency;
- infectious complications;
- splenic rupture.
Separate complication of malaria should be noted hemoglobinuric fever. It develops on the background of a massive reproduction of plasmodia, in the treatment of medical preparations, due to the destruction of erythrocytes (hemolysis). In severe cases, this complication to common symptoms and complaints of malaria attack is added to the progressive reduction in the formation of urine. Developing fulminant renal failure, often with early death.
Diagnostics
With periodic attacks of chills and fever for no apparent reason can always be suspect malaria, especially in cases when the patient visited over the past year or two foci of malaria years. A typical in diagnostics is the detection of malaria parasites in blood smears and large drop. It is necessary to identify the type of pathogen, because depend on this treatment and prognosis. Blood smears repeated after 4-6 hours, if the first swab was negative.
Thick drop preparing stretching great drops of blood by 15 mm on the glass so that the blood cells are laminated to each other. Smear can be dried. Carried by Giemsa stain or Rayt- Giemsa. After staining the smear can be washed with a buffer solution and dried in air. Since red blood cells are hemolyzed water unfixed thick drop, parasites appear as extracellular organisms against a background of red blood cell stroma. Using a thin brush strokes, which are fixed with methanol before painting - less sensitive method than the fat drop, but easy to interpret.
For the diagnosis of R. falciparum can be used at the bedside of the test strip with monoclonal antibodies to the rich histidine protein-2, which has an accuracy comparable to the blood drop, and requires less effort than microscopy. Informative PCR and other tests, but they are not widely used. Serological tests may reflect previous infection, but does not diagnose an acute process.
How to treat malaria?
All patients hospitalized with malaria in hospital infection.
Causative treatment of malaria:
- "Quinine" - fast-acting antimalarial drug that affects all strains of Plasmodium. The drug is administered intravenously. It is necessary to create a high concentration of drug in the blood serum. The duration of treatment "quinine" is 7-10 days. If intravenous drug becomes impossible, it is administered orally or intramuscularly. Treatment of one "quinine" is often insufficient. In such cases it is combined with the reception of the reception of the tetracycline group of antibiotics or other anti-malarial drugs.
- "Hloridin" is a drug, have a damaging effect on the various forms of plasmodia. This drug is quite effective, but is slower 'hingamin ". In severe cases, they are recommended to be taken together.
- "Hingamin" - widely used antimalarial drug, causing the death of parasites. Tablets prescribed to patients with malaria and is used to prevent infection. They should take after meals for 5 days. In severe cases, the drug is administered intravenously. Babies "Hingamin" administered by intramuscular injection twice with an interval of 6 hours. To accelerate and augment the therapeutic effect of the drug, it is administered together with anti-inflammatory and hormonal agents.
Besides causal treatment, symptomatic and pathogenetic treatment, including detoxification measures, restoration of microcirculation, anti-treatment, the fight against hypoxia.
Intravenously administered colloid, crystalloid, slozhnosolevye solutions "Reopoligljukin", isotonic saline, "Hemodez". Patients prescribed "Furosemide" "Mannitol", "Eufillin" conduct oxygen therapy, hemosorption, hemodialysis.
For the treatment of malaria complications using steroids - IV "prednisolone", "Dexamethasone". According to the testimony transfused plasma and packed red blood cells.
prevention
Malaria prevention requires a special reception tablets. Start their reception should be 2 weeks before the expected departure in the risk zone. Prescribe them can infectious disease physician. Continue to receive the designated tablets worth and after arrival (for 1-2 weeks).
In addition, to prevent the spread of infection in countries where the disease is not uncommon, measures are being taken to destroy the malaria mosquito. Windows of buildings are protected by special nets. If you are going to go to such a dangerous area, is to acquire a special protective clothing and do not forget about the reception of preventive pills.
Such preventive measures are almost completely eliminate the infection of this dangerous disease. In the event that there is at least a few of the above symptoms, you should immediately contact the infectious diseases. Timely treatment will allow almost completely get rid of the disease and prevent complications.
Development of malaria vaccines
Are under development and clinical trials of vaccines against malaria.
In July 2015 the European Medicines Agency issued a positive opinion on the vaccine "Moskiriks" (Mosquirix) from Plasmodium falciparum, are also widely known as «RTS, S / AS01», developed by British pharmaceutical by GlaxoSmithKline and proven by more than 15 thousand children. Vaccine showed an efficiency of about 30-40% when administered four times (0, 1, 2 and 20 months).
Publication of the European agency will facilitate obtaining permits for use in African countries. The World Health Organization will examine how safe use of the vaccine children who are most susceptible to this disease., The use of vaccines in some countries expected in 2017. The vaccine may be able to become an addition to the set of measures taken to combat malaria.