Brucellosis

Introduction to Brucellosis Brucellosis (brucellosis), also known as wavy fever, is an acute or chronic infectious disease caused by Brucella. It is a natural epidemic disease. It is clinically characterized by fever and sweating. Joint pain and so on. After the bacteria enter the blood circulation, new infections are formed in the reticuloendothelial system such as liver, spleen, bone marrow and lymph nodes. After the disease, the pathogens can enter the blood circulation several times and cause recurrence. The fever is wavy. basic knowledge The proportion of sickness: 0.004% - 0.005% Susceptible people: no specific people Mode of infection: contact spread Complications: meningitis bronchopneumonia

Cause of brucellosis

Bacterial infection (95%)

After the Brucella enters the human body from the skin or mucous membrane, the neutral polynuclear cells appear first, and the phagocytized bovine bacteria can be partially killed, but the sheep type bacteria are not easily killed, and the surviving Brucella goes to the local with the lymph fluid. Lymph nodes, according to the body's disease resistance and the number and virulence of the invading bacteria, the bacteria are either eliminated locally or grow in the lymph nodes to form a infection. When the bacteria proliferate to a considerable extent, they break through the lymph node barrier and invade the blood circulation. At this time, a series of symptoms such as bacteremia and toxemia may occur. After the bacteria enter the blood circulation, new infections are formed in the reticuloendothelial system such as liver, spleen, bone marrow and lymph nodes. After the disease, the pathogens can enter the blood circulation several times and cause recurrence. The fever is wavy (so the disease is also called Wavy heat). Brucella is mainly parasitic in macrophages. Like the chronic infectious diseases caused by bacteria in other parasitic cells, the pathogenesis is mainly delayed type allergic reaction.

Brucellosis prevention

1. Diseased animals must be isolated or slaughtered. Contaminated areas should be carefully disinfected. Milk and dairy products must be pasteurized.

2. Workers in popular areas should be vaccinated against vaccines. Attenuated live vaccine or 19-B vaccine can be inoculated in the herd.

3. Regular quarantine of livestock, and found that sick animals are isolated and treated, and sick animal products and dead animals must be buried deeply.

4. Disinfect the polluted environment with 20% bleaching powder or 10% lime milk. The fur can be fumigated with peroxyethane and placed in the infected area for more than 3 months. The pastures used by sick animals need to be naturally purified after 3 months.

Brucellosis complications Complications meningitis bronchopneumonia

Endocarditis, pericarditis, meningeal brain, meningitis, myelitis, bronchial pneumonia, pleurisy, endometritis, etc., individual patients may have aphasia, paralysis, hearing loss, deafness, keratitis, optic neuritis, retinitis , nephritis, pyelonephritis, etc., about 1% of pregnant patients with abortion,

Systemic brucellosis, also known as wave heat, has an incubation period of 5 to 30 days or longer. The initial patient has headache, back pain, general malaise and intermittent fever. Other symptoms such as gastrointestinal and nervous system can also occur. Half of the cases had lymph nodes and splenomegaly; 1/4 of cases had hepatomegaly; 10% of cases had non-specific rashes, more common were measles-like, scarlet fever and rash-like rash, and a few could develop papules, blisters or hemorrhagic The rash, as well as the report of ulcerative nodules in the calf, the disease has been indefinite, usually 3 to 4 months, with acute fulminant and extremely chronic type, the latter may have persistent bone, bladder or other organ infection, contact Brucellosis, also known as Brucella dermatitis, is more common in veterinarians and people who are often in contact with infected animals. Patients are highly allergic to Brucella antigens. Within a few hours of exposure to infected animal secretions, in contact with In the upper limbs, sometimes itchy red spots, papules or wheals can be resolved in the face and neck. After a few days, most of the scattered follicular papules appear in the face and become vesicles and pustules. After the blisters or pustules are scarred, the tissue underneath the tendon is necrotic. After 10 to 14 days, it is cured, leaving tiny scars, and sometimes a secondary erythematous erythematous rash occurs in the non-contact area. If the pathogen invades the skin and bruises the wound It can cause painless ulcers, and the patient has no systemic symptoms such as fever.

Brucellosis symptoms common symptoms leukocytosis testicular tenderness fever

Epidemiological data and occupations are of great value in assisting in the diagnosis of this disease. If there are some special clinical manifestations of this disease, such as wavy fever, orchitis, the diagnosis can be basically established, blood, bone marrow, pus and other cultures are positive. The result is the basis for the diagnosis.

Agglutination test (or ELISA, supplementation test, etc.) should be measured on a weekly basis, and the high-valence or titer should be diagnosed. If the agglutination test is negative, it should be used as an ELISA or anti-human globulin test to identify natural infections. And artificial immunization, or to determine whether the disease is active, can be used for 2-ME test.

Brucellosis check

(a) surrounding blood

The white blood cell count is normal or slightly lower, the lymphocytes are relatively or absolutely increased, the erythrocyte sedimentation rate is increased in the acute phase, the chronic phase is also high, and the anemia is unclear. It is only found in severe patients or those with delayed lesions.

(2) Various cultures

It takes a long time, and there is no growth after 4 weeks to give up. The positive rate of bone marrow culture is higher than that of blood, especially in the chronic phase. The blood culture positive rate of acute type sheep patients can reach 60%-80%. When the initial isolation of Lu bacteria, 10% of carbon dioxide is required. The bacteria can also be isolated from the cerebrospinal fluid and pus of urine, meningitis patients, and the specimen can be inoculated into guinea pigs or mice.

(3) Various immunological tests

1. Serum agglutination test The test tube method is an antibody that directly detects lipopolysaccharide antigen. The titer is 1:160, but it can be positive after injection. Therefore, double serum should be checked. If the titer is 4 times. Or above growth, suggesting a recent Brucella infection.

2. Enzyme-linked immunosorbent assay (ELISA) The positive rate of this method is higher than that of agglutination test, and the sensitivity of detecting IgM and IgG is similar. Because the antibody of chronic patients is of IgG type, this method can be used for both acute and chronic patients. The diagnosis has recently been performed using avidin enzyme-linked assays, which are more sensitive than ELISA.

3.2-mercaptoethanol (2-ME) test This method can detect IgG, which is used to identify natural infection and bacterial immunity. After natural infection for 1 month, the body aggregates with IgG type (initial IgM) Type), the IgG is resistant to 2-ME; and the lectin within 3 months after immunization is mainly IgM, which can be destroyed by 2-ME.

4. Compensatory test The supplemental antibody is also IgG. The effect of the third week of the disease can be more than 1:16. The positive rate of this test is higher than the agglutination test, and the specificity is also high, but the time is later than the agglutination test.

5. Anti-human globulin test patients can still produce an incomplete antibody, although the latter can bind to the antigen, but the naked eye is not visible, when the anti-human globulin immune serum is added to the antigen-incomplete antibody complex, it appears Directly visible reactions, incomplete antibodies appear early and disappear late, so it can be used for the diagnosis of patients in acute and chronic phase. In view of the complicated operation of this method, only suspicious patients with negative agglutination test are used, and the titer is >1:80.

6. Intradermal test Brucellin skin test is a delayed hypersensitivity reaction, 24-48 hours observation, only partial redness and no mass in the negative, local redness and hard fast diameter of 2 ~ 6cm Positive, the positive rate of skin test within 6 months of the disease is very low, nearly 100% of patients in the chronic phase are positive or strongly positive.

7. Other immunological tests include reverse passive hemagglutination test, radioimmunoassay, indirect immunofluorescence test, etc. Due to complicated operation, it is not suitable for general use.

(4) Other inspections

Cerebrospinal fluid examination is suitable for meningitis patients, cerebrospinal fluid cells increase (lymphocyte-based), protein is increased, the rest are normal, cardiac power production can show the new period of PR, myocardial damage, low voltage, etc., bone and joint X-ray examination It can be seen that soft tissue calcification, bone repair response is strong and destructive, the intervertebral disc and intervertebral space narrow, etc., liver function and EEG changes are non-objective.

Diagnosis and diagnosis of brucellosis

diagnosis:

The acute phase of the disease is susceptible to typhoid fever, paratyphoid fever, rheumatism, rheumatoid arthritis, influenza, other viral respiratory infections, viral hepatitis, malaria, lymphoma, systemic lupus erythematosus and other diseases, so It is easy to be confused, and it should be distinguished according to laboratory test results when identifying. The chronic phase of brucellosis should be differentiated from various bone and joint diseases, neurosis and the like.

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