Overview
Brucella pneumonia is an acute or chronic infection of the lungs caused by bacteria of the genus Brucella, which is a zoonosis of natural origin. The disease is widely distributed around the world, China’s northeast, north China, northwest animal husbandry areas are prevalent.
Etiology
It is an acute or chronic infection of the lungs caused by bacteria of the genus Brucella.
Symptoms
Clinical manifestations are complex, ranging from simple fever to acute sepsis. Early shock, often with multiple organ damage, lung involvement is common, generally cattle type is less severe, sheep type and pig type is mostly more severe, its manifestation can be acute, sometimes in the form of explosive septicemia, rapidly fatal, can also be chronic. In recent years, there is a trend of gradual reduction of the disease, manifested in the rapid onset of the disease, short fever, high fever patients significantly reduced, mild symptoms of intoxication, no obvious hepatosplenomegaly, various systems and organs damage is light, the reason may be related to the wider range of endemic areas of vaccination and the general application of antibiotics.
1. Acute stage
The onset of the disease is slow, and only a minority of patients have an acute onset. Most patients have aura symptoms of upper respiratory tract infection, and the main clinical manifestations in this period are as follows:
(1) Fever and excessive sweating with wave-like fever type is the most characteristic, can also be flaccid fever or irregular fever, fever lasts from one to several weeks, with an interval of several days to two weeks; high fever is often accompanied by chills and chills, the more prominent is excessive sweating, more than other febrile illnesses, often sudden drop in temperature, sweating, and accompanied by generalized fatigue, irritability, headache, loss of appetite, weight loss, and so on.
(2) Lung manifestations Cough, sputum, chest pain, dyspnea and other symptoms may appear, a few patients with dry cough, coughing sputum, sputum is mucous, purulent or bloody, occasional hoarseness, pleurisy, the lungs may be dry, wet rales and signs of solid changes.
(3) Arthralgia, characterized by wandering pain in large joints (shoulder, knee, sacroiliac and hip joints), small joints can also occur, asymmetric, with pain like pins and needles, and muscular pain, most common in the thighs and buttocks, sometimes with spasmodic pain.
(4) Liver and spleen enlargement Some patients may have enlarged liver, spleen and lymph nodes.
2. Chronic stage
Low-grade fever, cough, sputum, often mucopurulent sputum or occasional blood, more often involving the pleura, pleurisy, may be accompanied by loss of appetite, weight loss, fatigue, insomnia, arthralgia, neuralgia, mild enlargement of the liver, spleen and lymph nodes, the duration of the disease is a few months to a few years, and some patients have more than two years of illness, and joints may be stiff or contracted in the long term.
Examination
1. Blood picture
The white blood cell count is within the normal range or low, the lymphocyte count is relatively or absolutely increased, sometimes abnormal lymphocytes can be seen, the blood sedimentation rate is increased, and some cases may have normochromic macrocytic anemia.
2. Bacterial culture
Blood culture and bone marrow culture can isolate pathogenic bacteria; in acute stage or relapse, it can reach 70%～80%, and bone marrow culture can be higher; pleural effusion, bronchoalveolar lavage fluid, enlarged lymph nodes, and biopsy of granulomas in lungs can also isolate pathogenic bacteria, and other bacteria such as cerebrospinal fluid (in cases of meningitis), bursal fluid of joints, breast milk, vaginal secretion, urine, feces, etc. can also isolate pathogenic bacteria.
3. Serologic examination
(1) Borrelia burgdorferi agglutination test ① Slide agglutination reaction is highly sensitive, any obvious agglutination within 5-10 minutes is considered positive. ② tube agglutination test has a high specificity, this reaction is generally 7 days after the infection can be positive results, to the second week is often strong positive, single serum agglutination potency of 1:100 or more, or double serum agglutination potency of more than 4 times higher to help diagnose the disease. ③ The standard of positive closed antibody is 1:160～1:320, which is an important experimental diagnostic method in chronic brucellosis. (4) Serum agglutination reaction with sulfhydryl compounds, such as the serum potency after treatment is 20% to 30% lower than the total potency before treatment, which is diagnostic significance.
(2) Complement binding test Complement binding antibody (mainly IgG) appears later, 20 to 25 days after the onset of the disease, its titer potency of 1:16 or more is positive, the sensitivity is not as good as the agglutination reaction, but the specificity is high, and plays a decisive role in the diagnosis of brucellosis.
(3) Delayed cutaneous metamorphosis Intradermal injection of Brucella abortus or Brucella abortus protein extract to determine cutaneous metamorphosis, 24～48 hours observation results, infiltration of 1～2cm is weakly positive, 2～3cm is positive, 4～6cm is strongly positive.
4. X-ray examination
It usually shows infiltrating shadows or single granulomatous lesions around the hilum and bronchus, unilateral hilar lymph node enlargement and pleural effusion are rare, and there may be pulmonary fibrosis or calcification in the chronic stage.
5. Arthrography
It shows narrowing of the hip joint space, thinning of the bone on both sides of the joint, accompanied by osteomalacia or sclerosis.
Diagnosis
1. Epidemiologic information and occupation are valuable in assisting in the diagnosis of the disease.
2. Clinical manifestations include recurrent fever, excessive sweating, arthralgia, cough, chest pain, dyspnea, and other symptoms, most often accompanied by signs of liver, spleen, and lymph node enlargement, but other suspected diseases should be excluded.
3. The diagnosis can be confirmed by culture of Brucella abortus in blood or sputum or tissue specimen.
4. Combined with clinical manifestations for specific antibody detection, serological tests such as agglutination potency of 1:160 or more or potency increased more than 4 times the diagnostic value.
5. Biopsy of lung tissue, bone marrow and lymph nodes to find granulomatous changes can help the diagnosis.
Treatment
1. Antibacterial treatment
(1) In the acute stage, it is advisable to give drugs in combination. Tetracycline oral, plus streptomycin intramuscular injection. In order to reduce recurrence, the course of treatment is often longer. Some people also advocate a multi-course treatment. Methotrexate can also be given orally with streptomycin intramuscularly or with rifampicin.In 1986, WHO recommended the use of doxycycline (doxycycline) with rifampicin for the treatment of brucellosis. Other antibiotics against gram-negative bacilli, such as gentamicin, canamycin, ampicillin (ampicillin), erythromycin, chloramphenicol and so on also have considerable efficacy.
(2) Chronic phase Antibacterial drugs are still effective, but the course of tetracycline should be extended to more than 6 weeks, streptomycin to 4 weeks is appropriate, in the longer term should pay close attention to the toxic side effects of drugs, especially chloramphenicol on the bone marrow inhibition. Oral administration of ofloxacin plus rifampicin was used, and the results showed that the therapeutic efficiency was extremely high. In addition, quinolones are also one of the drugs used in the treatment of brucellosis, which should be listed as the first choice and be used together with other drugs.
2. Vaccine treatment
Generally used in the chronic stage. There are many application methods of mycobacterial vaccine therapy, intravenous, intramuscular, subcutaneous, intradermal method can be used. Among them, the intravenous method has the best efficacy. Mycobacterial seedling therapy has good near-term efficacy and poor long-term efficacy.