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Visceral leushmaniosis (kala azar) — the natural and focal transmissible disease caused by different types of leyshmaniye, which is characterized by a chronic current, periodic fever, a splenohepatomegalia, anemia, a cachexia.
Lat. — leishmaniosis visceralis.
English — visceral leishmaniasis, kala-azar.
Some epidemiological features.
Transmissible way of transfer, certainly, the main. However in separate, though exceptional cases, also some nonconventional ways of infection are possible. So, it is possible to catch at transfusion of the infected blood, and also at sexual contact with a sick visceral leushmaniosis. Parasites were found in some patients in a nasal secret. Animals can catch, eating carcasses of the sick (infected) animals. In experiment the possibility of infection at rubbing in in leather of the pounded infected mosquitoes is proved.
In endemic regions the special risk group is represented by the persons receiving immunodepressive therapy: at them the leushmaniosis quite often arises as an opportunistic infection. Same treats HIV-positive people.
Taking into account features of a clinical current, geographical distribution, a carrier, type of the activator, a source in the nature the visceral leushmaniosis is divided on:
- Mediterranean visceral leushmaniosis (children's leushmaniosis, children's kala azar);
- Indian visceral leushmaniosis (Xing.: Indian kala azar, fever of thoughts thoughts, Sikari's illness, Sernariya's illness, tropical fever, cachectic fever, Assamese fever, etc.);
- the African kala azar (sometimes separately register a Sudanese kala azar);
- American kala azar.
At a krovososaniye promastigota which, turning into amastigota, are implemented into endothelial cells where there is their reproduction get to a wound on skin. The part of them breeds also in mononuclear cells which are brought then a blood flow in RES cells (a liver, a spleen, marrow, lymph nodes). In these bodies there is an active reproduction and accumulation amastigot, periodically coming to blood. Active reproduction of leyshmaniye in cells of RES leads to damage of bodies, disturbance of their function. With parasites the sharp hypertrophy of a spleen is caused by accumulation of a large number of mononuclear cells, in it the anemic centers, hemorrhagic heart attacks are formed. When progressing a disease Banti's pseudo-syndrome forms (a splenomegaly combination to hypoplastic anemia, disturbance of blood circulation in splenic and portal veins owing to their thrombosis).
In a liver reproduction of leyshmaniye happens mainly in kupferovsky cells, many of them are completely filled with parasites that is followed by their hyperplasia and proliferation, formation of zones of a necrosis; in the subsequent expansion of hepatic capillaries, increase in body is observed. Growth of fibrous fabric and an atrophy of hepatic beams can lead to forming of cirrhosis.
In marrow, lymph nodes a large number of the mononuklear filled with leyshmaniye is also found, necrotic and degenerative processes here too develop.
It are found a leushmania in a cardiac muscle, adrenal glands, a parotid gland, i.e. practically everywhere where macrophages get. In a duodenal and small bowel they can infiltrirovat a submucosal layer, and be in certain cases even the cause of superficial ulcerations. In some cases can be surprised (to ulcerate) a mucous membrane of an oral cavity, a nose, almonds.
More detailed idea of the disturbances happening in an organism at a visceral leushmaniosis gives tab. 1.
It is necessary to remember that surely the patient will have not all these symptoms, existence and their expressiveness depend on the period of an illness, its duration, features of the strain which caused a disease.
Essential change is undergone by immune system which influence both a leushmania, and products of their metabolism and disintegration. In blood the content of immunoglobulins increases, there are cell-bound immune complexes having the additional damaging effect (in particular, on kidneys).
The course of a disease and its outcomes considerably depend on function of T lymphocytes, on their ability to activate activity of macrophages software destruction of leyshmaniye.
If stimulation of a cellular host defense was sufficient, a leushmania are destroyed completely or the disease proceeds subclinically if weak — active reproduction of leyshmaniye continues and the illness develops.
Table 1. Pathogeny of separate symptoms and syndromes
Continuation of tab. 1
Hemopoiesis oppression (it are found a leushmania in marrow)
Hemolysis of Bleeding
Deposition of uniform elements in a spleen
Hemopoiesis oppression Deposition of uniform elements in a spleen (the expressed anemia and a leukopenia do not develop at the splenectomized patients)
Yellowness of skin
Intravascular hemolysis Damage of a liver
In experiment it is shown that introduction by an animal of T lymphocytes from an immune animal protected them from an infection whereas administration of immune serum even with high antiserum capacities — is not present. The same conclusions were drawn at supervision over the people who were ill a leushmaniosis. In spite of the fact that in experiment of in vitro serum with high antiserum capacities caused a komplementoposredovanny lysis of leyshmaniye, it did not protect the person from a course of a disease. But accurate correlation between a positive intracutaneous test and resistance to leyshmaniye is established. During the acute period of a visceral leushmaniosis test will be negative whereas after subsiding of the acute phenomena at recovered it becomes positive.
As for factors of humoral protection, as a result of proliferation of cells of RES there are products of polyclonal, not protective immunoglobulins.
The people having any chronic diseases, deficit of food as they have no good cellular protection are especially subject to a leushmaniosis. In turn, the leushmaniosis is followed by sharp reduction of number of leukocytes that promotes emergence on its background of various complications or a mikst-infection.
The disease has bent to a long and chronic current, but it can end with liberation from leyshmaniye and recovery. Whether any residual phenomena will be created (in particular, cirrhosis) — depends on duration of a current, its weight.
Approach of clinical recovery not always demonstrates liberation of an organism from leyshmaniye. Several years later the illness can sometimes enter new quality — postkalaazarny leishmanoids (the multiple small small knots on skin containing leyshmaniye) develop. Such small knots can remain years and even decades.
Immunity forms against a homologous strain, there is no cross immunity usually. Reinfection the same strain is possible in the presence of an immunodeficiency.