Kala-azar

Introduction to black fever Kala-azar is a chronic endemic infection caused by Leishmania donovani (black fever protozoa), which was popular in the north of the Yangtze River. The source of infection is the patient and the sick dog (skin dog), which is transmitted through the daytime, and is the season of white pheasant from May to August every year. When the white sputum sucks the blood of the patient, the protozoa enters the ferrets and develops into a flagellate. After 7 days, the white is white. When you bite the human body again, inject the flagella body to cause infection. Protozoa mainly live in the blood, liver, spleen, bone marrow and lymph nodes of patients. basic knowledge The proportion of illness: 0.0055% Susceptible people: no specific population Mode of transmission: insect vector transmission Complications: Bacterial dysentery Agranulocytosis Swelling Amyloidosis Hematuria

Cause of kala-azar

Black fever protozoal infection (80%)

Leishmaniasis is a zoonotic disease. In addition to being transmitted from person to person, it can also be transmitted between animals and people, animals and animals. The source of infection is the patient and the sick dog (the fur dog), which is transmitted through the day. Every year from May to August is the activity season of white pheasant. When the white sputum sucks the blood of the patient, the protozoa enters the ferrets and develops into a flagellate. After 7 days, when the cockroach licks the human body again, the flagella is injected. infection.

Black fever prevention

The main preventive measures are treating patients and killing dogs. At the same time, DDV, trichlorfon and other drugs are sprayed during the white season to kill white mites and prevent their growth.

(1) Before the arrival of the epidemic season, all patients are census and all patients are regularly followed for one year to seek radical cure.

(2) In areas where both black fever and canine visceral leishmaniasis are present, especially in hilly areas, it is difficult to treat patients with black fever by treating patients. It is necessary to regularly check the dogs and find that the dogs should be culled.

(3) In the epidemic area, from May to September every year, during the day of activity, it is necessary to take measures to eliminate cockroaches in the living room, cloakroom, etc.

(4) Improve the hygiene of the living room during the popular season, keep the ventilation and light and dry on the ground, prevent adulthood and young adolescents, and expose the exposed part of the field workers to remove the repellent. At night, you can use the silkworm nets to prevent white bites. Do personal protection.

Black fever complications Complications Bacterial dysentery Agranulocytosis Swelling amyloidosis Hematuria

(A) secondary bacterial infection is easy to be complicated by pulmonary inflammation, bacterial dysentery, gum ulceration, walking horses and so on.

(B) acute agranulocytosis manifested as high fever, extreme exhaustion, oropharyngeal ulcer, necrosis, local lymph node swelling and peripheral blood picture of granulocytes significantly reduced or even disappeared.

(C) due to thrombocytopenia, patients often have symptoms such as epistaxis and bleeding gums.

(4) Proteinuria and hematuria may also occur due to glomerular amyloidosis and deposition of immune complexes in the glomeruli.

Symptoms of kala-azar common symptoms splenomegaly papules eosinophilia

Cell hyperplasia is the basic cause of spleen, liver and lymph node enlargement. The most common splenomegaly, the incidence rate is above 95%. In the later stage, it is hardened by the proliferation of reticular fibrous connective tissue. The amount increases, the albumin appears, the globulin ratio is inverted, the IgG titer in the globulin is increased, and the red blood cells, white blood cells and platelets in the blood are reduced. This is due to the hyperfunction of the spleen and the massive destruction of blood cells in the spleen. Immune hemolysis is also an important cause of anemia. Skin type kala-azar: skin lesions and visceral concomitant concurrently, accounting for 58.0%; some patients (32.3%) have disappeared after many years of visceral disease; a few (9.7%) have no viscera Infected, no primary disease patients with a history of black fever, except for a few fading types of skin damage, most of them are nodular, nodules with granuloma of varying sizes, or dark papules, common in the face and neck, in No-flagellate can be found in the nodules, lymph node type kala-azar: this type of patient is characterized by no history of kala-azar, local lymph nodes, varying sizes, superficial, no pressure , No swelling, increased eosinophils, lymph node biopsy can be investigated, see amastigotes in epithelioid cells.

Black fever check

Common methods for pathogen examination are:

(1) Puncture examination

1) Smear method: using bone marrow puncture for smear, staining, microscopic examination, this method is most commonly used, the protozoan detection rate is 80% to 90%, lymph node puncture should be superficial, swollen, detection rate 46% ~ 87%, can also do lymph node biopsy, spleen puncture detection rate is high, up to 90.6% ~ 99.3%, but not safe, less use.

2) Culture method: the above-mentioned puncture is inoculated into NNN medium and placed in a thermostat at 22 to 25 ° C. After one week, if the active pro-flagellate is found in the culture, it is judged as a positive result, operation and culture process. Sterility should be strictly observed.

3) Animal inoculation method: the puncture is inoculated into susceptible animals (such as hamster, BALB/c mice, etc.), the liver is taken after 1 to 2 months, the spleen is printed or smeared, and the stain is stained with Wright's dye solution. Check.

(2) skin biopsy

Use a sterile needle to puncture the skin at the skin nodules, take a little tissue fluid, or use a scalpel to pick up a little tissue for smear, stain, and microscopic examination.

Black fever diagnosis and identification

diagnosis

Immunodiagnosis:

(1) Detection of serum antibodies: such as enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination test (IHA), convective immunoelectrophoresis (CIE), indirect fluorescence test (IF), direct agglutination test, etc., high positive rate, false positive rate Higher, in recent years, the use of molecular biology methods to obtain pure antigen, reducing the false positive rate.

(2) Detection of circulating antigen: monoclonal antibody antigen spot test (McAb-AST) is used to diagnose kala-azar, with high positive rate, sensitivity, specificity and reproducibility. It can be used only for trace serum and can be used for therapeutic evaluation. .

Molecular biological methods: In recent years, the use of polymerase chain reaction (PCR) and DNA probe technology to detect kala-azar has achieved good results, sensitivity, specificity, but the operation is more complicated, and has not been widely promoted.

Differential diagnosis

The disease is identified by tuberculosis, typhoid fever, malaria, brucellosis, leukoemia, malignant histiocytosis, Hodgkin's disease, chronic schistosomiasis and other causes of cirrhosis, and acute bacterial periostitis. .

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