Kala-azar-visceral leishmaniasis

Kala-azar-About Kala-azar:

Kala-azar, also known as visceral leishmaniasis, kala-azar caused by Leishmania donovani, transmitted by sandflies of chronic endemic infectious diseases clinical long-term irregular fever, splenic swelling, weight loss, anemia, leukopenia and plasmaglobulin characteristics.

Kala-azar - Disease description:
Kala-azar virus diseases caused by Leishmania infection, known as leishmaniasis. Leishmaniasis is widely distributed in many countries of Asia, Europe, Africa, Latin America and other continents. Serious harm to human body zoonotic parasitic diseases. The global prevalence of TDR (1989) more than 12 million each year to 4 million new infections; 4.2 million died from the disease in 1998. Clinical damage Organization,

Leishmaniasis can be divided into three different types:
① visceral leishmaniasis (VL) in India, often dark pigment of the skin of patients calm and have a fever, so called the kala-azar, against Leishmania donovani visceral organs (such as the spleen, liver, bone marrow, etc.) Erzhi diseases. Failure to receive timely treatment, can often fatal.

② mucocutaneous leishmaniasis, caused by the Brazilian Leishmania. Protozoan parasitic cause skin lesions on the skin, via lymph or blood to invade the nasopharyngeal mucosa, can cause mucous membrane lesions. In severe cases, the nasal septum, and even the cartilage of the larynx and other organs are also injury. Distributed in Central and South America, Africa, Ethiopia and Sudan have a case report.

③ cutaneous leishmaniasis. Popular in Africa, Latin America, Southwest Asia, the Mediterranean basin and the former Soviet Union in some areas. Caused by the tropical Leishmania and Mexico Leishmania. Tropical Leishmania can be divided into two separate subspecies of Leishmania tropical Leishmania. The two subspecies have different features in morphology: clinical manifestations and epidemiology. Chinese kala-azar caused by Leishmania donovani.

Kala-azar is widely distributed in the world. Occurs mainly in India, China and Bangladesh, and Nepal in Asia. Mediterranean coastal regions and countries in East Africa, North Africa, Europe, former Soviet Central Asia, some countries in Central and South America the disease epidemic.

Kala-azar - signs and symptoms:

Suffering from kala-azar, kala-azar make immunocompromised immunocompromised patients not only have specific cellular immune suppression, but also up pathogenic organisms ability to generate cellular and humoral immune response to reduce, that is, non-specific inhibition of this patient's body protozoa breed fast, too much to produce antigens, and the collective in the immune response is related. Human innate immunity of Leishmania donovani, leishmaniasis is more common in infants and children. The prognosis for kala-azar, however acquired immunity can be a solid product that can resist re-infection with Leishmania. Kala-azar patients cured Houlishiman prime intradermal test (LDT) positive was a curve of 20 - 29 years reached a peak, after a downward trend, the positive reaction can be maintained as long as 50 years, the response intensity does not diminish. Seen patients cured, the availability of life-long immunity. Skin kala-azar (PkDL) part of kala-azar patients in the course of treatment with antimonials or cured after a few years or even ten years after the occurrence of skin kala-azar. Patients in other parts of the face, neck, limbs or trunk of many with Leishmania skin nodules, nodules were of varying sizes granuloma. Or was dark papules common in the face and neck, some resembles lepromatous leprosy. Type skin kala-azar in China first in the prime was found three cases of the 1950s, has been reported that more than 100 cases. In 1988, 55.0% of simultaneous damage to the skin and internal organs, 35% of patients with visceral lesions disappeared after many years, and 10% of patients had neither check to see visceral infection, nor kala-azar history.

The the lymph kala-azar (LGVL) kala-azar history, lesions were confined to the lymph nodes visceral leishmaniasis, also known as lymph node-type kala-azar.

Kala-azar/visceral leishmaniasis - disease etiologyDogs kala-azar bacteria, depending on the source of infection, kala-azar epidemiology can be broadly divided into three different types, namely, the human type, the type of dog sources and natural foci of type; analysis of India, the Mediterranean basin and the Central Asian desert of kala-azar are typical examples.
(1) people Source: also known as the plain type, more common in the plains, located in the Huang-Huai region of northern Jiangsu, Anhui, Lunan, Yudong and southern Hebei, northern Hubei, Shaanxi, Guanzhong and within the Xinjiang Kashi ground. Mainly in the population distribution of kala-azar patients with youth-oriented, baby, dogs rarely infected patients as the main source of infection. Media home habitat type sandflies and Xinjiang long tube sandflies. Such areas, kala-azar has been controlled, no further new cases have been in years, but even can be found in the skin type of kala-azar.
(2) dogs Source: also known as hill-type, more common in the mountainous area, located in the outskirts of counties in Gansu, Qinghai, Ningxia, northern Sichuan, northern Shaanxi, Hebei, Northeast, Liaoning and Beijing, human infections from dogs . Patients scattered, the vast majority of patients are children, the baby's infection rate is high, the adults rarely get sick. Media for wild habitat type sandflies. Such areas as Chinese kala-azar endemic areas.
(3) natural foci: also known as the desert type, distributed in some desert areas of Xinjiang and Inner Mongolia. The patients were mainly seen in infants and young children under 2 years of age more than 90% of patients. Adult access to such areas often suffer from the lymph node type kala-azar cases of dissemination. Media of wild habitat Chrysopa, Wu sandfly followed Alexander sandfly. Animal host has not yet been found. Desertification affected areas and the hills affected areas Leishmania kDNa the homology, while the smaller and plain-affected areas of the kDNA homology. Therefore, the three popular types of pathogens like Leishmania loved ones can be summarized gondii strains (ie, the type of human worm strains) and pro-animal strains of insects (including the dog source type natural foci gondii strains).
It can be speculated that kala-azar was originally some wild animal diseases in the process of biological evolution, the Leishmania passed from wildlife to dogs, and then transmitted to humans by dogs. In this process, the Leishmania genes mutate, and been preserved in the new host and the environment, the gradual formation of different types of kala-azar pathogens.

Kala-azar - diagnostic testsKala-azar microscope, the pathogen checkDetection of pathogens can be confirmed. Should be noted that disseminated histoplasmosis identification of fungal disease, the disease is spread through the respiratory tract, fungi prevalent in tropical and subtropical. Patients with prolonged fever, hepatosplenomegaly, pancytopenia, and other symptoms. Sporozoite diameter 2-4μm, oval mostly involved the monocyte-macrophage cell system, bone marrow smears of findings pathogens and Leishmania, but no kinetoplast.
(1) biopsy 1) smear: a bone marrow aspiration smear is most common. Iliac bone puncture is simple, safe, and protozoa detection rate of 80% -90%. Multiple choice enlarged lymph node biopsy, lymph nodes, such as the groin, humeral trochlea, neck lymph nodes. The detection rate of about 46% -87%. Can also be used as a lymph node biopsy. Spleen puncture a higher detection rate of 90.6% -99.3%. However, unsafe, generally less or not. 2) culture: these puncture inoculated in NNN medium with sterile method, the temperature inside the set of 20 ℃ -25 ℃. After about one week in culture to check to see movement and lively before flagella, sentenced to a positive result. This method is more sensitive smear. But takes a long time, with the Schneider's medium, the better. 3 days to appear before the flagellar body. Strict aseptic culture. 3) animal inoculation method: biopsy material inoculated into susceptible animals (such as the golden hamster, in BALB / c mice, etc.) 1 - 2 months after the liver, spleen for imprint smear, Wright's dye staining .(2) Skin biopsy: skin nodules with a sterile needle punctured the skin, take a little tissue fluid with a scalpel to scrape a little organization smear, staining,
2, immune diagnosis method
The research focus of the immune diagnosis of parasitic diseases in order to transfer from the detection of antibodies to the detection of circulating antigen. From kala-azar immune Diagnostic Research Center, the superiority of the latter.(A) serum levels of circulating antigen: monoclonal antibody - antigen spot test (McAB-AST), For the diagnosis of kala-azar, the positive rate of 97.03%. False positive 0.2%. The sensitivity, specificity, reproducibility was good, and has a simple and feasible, only micro serum, etc., if necessary, to do the quantitative determination. The law also has to reflect the current infection, to determine whether the "cure" or "relapse" unique advantages.(2) detection of serum antibodies: such as enzyme-linked immunosorbent assay (ELISA). Indirect hemagglutination test (IHA), counter immuno electrophoresis (CIE), an indirect assay (IF), direct agglutination test (DA) and so can be used. The dot-ELISA-positive rate was also higher, but check antibodies are often associated with cross reaction to other diseases, has its limitations in the diagnosis of leishmaniasis, and the antibody easily disappear in the short term, is not easy for efficacy assessment.(3) the Leishmania prime intradermal test: The method is simple, so the earlier and more widely used in kala-azar epidemiology. Of the Act must be in the patient healed, only positive reactions, and to maintain a very long time, or even a lifetime to keep positive, it can not be used as diagnostic tools of the present patients. Used to determine the affected areas and non-infected areas, to determine the prevalence and assessment of control effect, has a certain value.
3, molecular biological methods
(1) polymerase chain reaction (PCR): better detection of kala-azar, sensitivity and specificity are high. Chinese scholars L, was amplified by PCR. d species-specific kDNA fragments used for diagnosis of kala-azar, the positive rate of 95.5% (21/22), and bone marrow smears from 91% (20/22), all controls were negative. Reverse transcription - polymerase chain reaction (RT-PCR), the diagnosis of kala-azar, the method is compared with rDNA as the template RCR method is sensitive to 100 times higher.
(2) kDNA probe method: This method is sensitive, specific, easily obtained. Assay Sichuan kala-azar endemic area 71 dogs marginal ear skin tissue, the positive rate of 40.8% (29/71). The coincidence rate of 85.9% (61/71) and bone marrow smears.

Kala-azar - treatment program

Kala-azar China to take the check treatment in the majority of kala-azar endemic areas, kill dogs and comprehensive measures in the eradication of media sandflies, 1958, China announced that the basic elimination of kala-azar. The number of patients has been dropped by 53 million in the 1950s the annual number of patients 100 cases. Kala-azar occurred pandemic required for natural and social factors still exist, should be active in the prevention and control of kala-azar.
The liberation of the early treatment of kala-azar, pentavalent antimonials sodium stibogluconate, domestic agents better for Adams antimony black g.

Suffering from kala-azar in immunocompromised patients not only have specific cellular immune suppression, and reduced ability of the cellular and humoral immune response, that is, non-specific inhibition up pathogenic organisms, which is fast with the patient's body protozoa breeding, resulting in antigen too and more collective in the immune reaction is related.

Kala-azar - prevention
Face kala-azar patients with the control of the media: the elimination of media Sandfly is a fundamental measure of the control of kala-azar, the need for a fundamental sandfly ecological habits, to take the measures appropriate countermeasures. Bromine cyanide Ju fat residual spraying, long tube of the family dwelling or the home habitat of sandfly kill better. Personal protection should be strengthened, to reduce and avoid sand flies sting.

Recurrent preventive measures:
(1) in the affected areas sandfly season before the advent of mass screening and cure all patients, and patients regularly pursued for one year, and strive to cure.
(2) In all areas of kala-azar and canine visceral leishmaniasis, especially in the hilly areas, only the treatment of patients is difficult to guarantee eradication of kala-azar, regular registration check on the dogs and found dogs should be culled buried.
(3) The affected areas from May to September each year sandfly activity season in the living room, circle toilet attached to measures to take off lacewing.
(4) popular season to do a good job in the health of the living room, keep the air and light and the ground was dry, to prevent mature hiding and young of breeding, field staff exposed part rubbed repellent, sleep at night can be used spinning mosquito nets to prevent sandfly bites. good personal protection.