Pulmonary nocardiosis
Introduction
Introduction to lung nocardiosis Nocardiosis is a purulent granulomatous lesion caused by Nocardia. The lung is the most common organ to be affected. Nocardia and systemic nocardiosis account for about all Nocardia. 85% of the disease. About half of the lung nocardiosis is associated with extrapulmonary lesions; however, nocturnal pulmonary nocardiosis causes only one-fifth of the disseminated. basic knowledge The proportion of sickness: 0.006% - 0.009% Susceptible people: no special people Mode of infection: non-infectious Complications: sepsis
Cause
Cause of pulmonary nocardiosis
(1) Causes of the disease
Nocardia is a genus of actinomycetes. It is known that 9 species of Nocardia can cause three kinds of diseases in humans, namely N. asteroides and Nocardia brasiliensis. .braziliensis) and Otitidis Nocardia (Notitidiscavarum, formerly known as Nocardia guinea), the two most common in the past, this is an inactive, curved aerobic Gram-positive bacillus, partially acid-resistant, about 1m wide, The fungus is fine, and it grows and multiplies by two divisions, but the cells still adhere to each other, and the branched mycelium is connected to grow up to 50 m. The final hyphae breaks and becomes a bacillus or cocci. It is not a real fungus. Some people call it a fungus. ", epidemiology: Nocardiosis is found in all parts of the world. In the United States, 500 to 1000 cases of this disease were diagnosed in one year, mostly adults. The ratio of male to female is about 2:1. There is no difference between the onset season and the patient's occupation. Nocardia is parasitic. In soil humus, mycelium can be formed in the air. Human inhalation of hyphal fragments is the main route of infection. It can also cause infection through damaged skin or digestive tract. It is usually sporadic, but there are 4 cases in the literature. Cardiac small-scale outbreak The first case was the incidence of 6 patients in the renal dialysis unit, but the mechanism of transmission was not determined. The second case was caused by the injection of liquid contaminated to cause subcutaneous abscess, and the third and fourth cases occurred in tumor and kidney transplant recipients. May be caused by mutual transmission between patients, but there is not enough evidence to show that human-to-human transmission, lymphoma, organ transplantation and AIDS are at high risk for this disease, nocardiosis in alveolar proteinosis, Tuberculosis, chronic granulomatosis, alcoholism, and diabetes are also common, but their relevance is not fully affirmed.
(two) pathogenesis
People who are frequently exposed to Nocardia hyphae usually do not develop disease. Neutrophils can inhibit Nocardia. Although not as effective as normal bacteria, the mechanism may be related to the action of lysozyme and other cationic proteins. The phagocytes and T lymphocytes play an important role in controlling and killing the bacteria. Nocardia is resistant to phagocytic respiratory burst products, but patients with chronic granulomatous disease are abnormally sensitive to Nocardia, suggesting that phagocytic respiratory bursts are correct. The pathogenesis of cardobacteria is still very important, so the weakening of the host immune defense mechanism is an important factor in the pathogenesis of this disease. The main pathological changes are suppurative granuloma with a large number of neutrophils, plasma cells, tissue cell infiltration, tissue necrosis and Form an abscess, and tend to fuse, hyphae can be found in the abscess, the latter aggregate to form loose particles, the bacterial sheath is not obvious, the lung tissue can be acute, subacute or chronic suppurative lesions, manifested as fusion bronchopneumonia, lung Consolidation, necrotizing pneumonia with cavity formation, and often involving the pleural effusion to produce pleural effusion, empyema, even can invade the chest wall to form fistula, lung The lesion can also directly invade the pericardium and mediastinum, and even oppress the superior vena cava. A few cases spread through the bloodstream, most often invading the brain tissue, forming a brain abscess; followed by the kidney, heart, liver, spleen, and lymph nodes can be involved.
Prevention
Nocardiosis prevention
Early detection and early diagnosis are the key to the prevention and treatment of this disease. It should be clearing away heat and detoxification, softening and stasis, and Torrey pus. The side uses the sore drink to add or subtract. Such as the formation of the fistula can be 3 ~ 6g / d inside the ivory, in order to support the dead bone, and can be used externally back to the smoked smoked tube, smoked with red blood medicine rubbed purple hemorrhoids cream, into the fistula to reduce rot Table that promotes healing.
Complication
Lung nocardiosis complications Complications sepsis
Combined with sepsis, a small number of empyema.
Symptom
Pulmonary nocardiosis symptoms Common symptoms Anorexia, weakness, purulent fatigue, chest pain, urgency, abscess, hemoptysis
The onset is slow, the immune function is low, often acute onset, systemic symptoms have fever, fatigue, weakness, anorexia, respiratory symptoms, cough, sticky purulent, usually not much, chest pain, shortness of breath, hemoptysis, etc. Visible fistula, no treatment or treatment delays turn into chronic, the corresponding manifestations of chronic infection similar to tuberculosis, chest X-ray showed inflammatory infiltration, consolidation, single or multiple nodular shadows, often abscesses and cavities, Occasionally thick-walled cavities, lesions are more common in the two lower leaves, can also be miliary or diffuse interstitial infiltration, minimal calcification and fibrosis, about 1/3 of patients with empyema.
All patients with pulmonary suppurative lesions with empyema, especially those with chest wall fistula, should be highly alert to the possibility of the disease, diagnosed dependent on sputum, lower respiratory secretion or pleural fluid culture and lung biopsy, serological methods and skin tests. Diagnostic significance.
Examine
Examination of lung nocardiosis
Blood routine examination can be found that neutrophils are elevated, and the total number of red blood cells is reduced, and hemoglobin is decreased.
Chest X-ray shows inflammatory infiltration, consolidation, single or multiple nodular shadows, often abscesses and cavities, occasionally thick-walled cavities, lesions are more common in the lower leaves, can also be miliary or diffuse Qualitative infiltration, minimal calcification and fibrosis, about 1/3 of patients with empyema.
Diagnosis
Diagnosis and identification of pulmonary nocardiosis
The common pulmonary tuberculosis, pneumonia, tumor, and actinomycosis are confused and should be identified.
