Tuberculosis

Introduction to tuberculosis Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis complex (Mycobacterium tuberculosis complex, referred to as Mycobacterium tuberculosis or Mycobacterium tuberculosis), which can affect the multiple organ system of the whole body. The most common diseased part is the lung, which accounts for the total number of tuberculosis in various organs. 80-90%. It can also involve organs such as liver, kidney, brain, and lymph nodes. The main routes of transmission are the respiratory tract, the digestive tract, the skin and the uterus, but mainly through the respiratory tract. After the sputum of the sterilized tuberculosis patient is dried, the bacteria fly with the dust and are inhaled by others to cause infection. Whether the human body inhales the droplets containing M. tuberculosis is mainly caused by the amount of inhaled tuberculosis, the virulence, and the body's resistance. And so on a variety of factors. The treatment is administered as soon as it is discovered and diagnosed. basic knowledge Sickness ratio: 0.1% Susceptible people: no special people Mode of infection: respiratory transmission Complications: conjunctival tuberculosis duodenal tuberculosis

Cause of tuberculosis

Causes

The Mycobacterium tuberculosis complex includes Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium, and Mycobacterium vaccae, and the main cause of human diseases is Mycobacterium tuberculosis. Mycobacterium tuberculosis is 0.3-0.6 um x 1-4 um in size, small and slightly curved, and slightly blunt at both ends. Acid-fast staining is an important characteristic. Once the majority of bacteria positive for acid-fast staining in the specimens are clinically representative of Mycobacterium tuberculosis, culture and further strain identification are still needed. Tuberculosis grows slowly, and it takes at least 2-4 weeks for visible colonies.

The cell wall of tuberculosis is rich in lipids, accounting for about 60% of the cell wall. The main components are mycolic acid and acidified trehalose. The former is the material basis for the acid-resistant coloration reaction; the latter includes trehalose dimycolic acid and thioglycolic acid, which respectively mediate granuloma formation and promote the survival of bacteria in phagocytic cells. The cell wall still contains lipopolysaccharide, wherein the lipid arabinomannan has a wide range of immunogenicity, and the growing tuberculosis bacteria can be produced in large quantities, which is a kind of antigenic substance which is widely used in serological diagnosis.

Pathogenesis

Tuberculosis enters the human body and is engulfed by macrophages. The presence of bacteria in the cells and the host immune response caused by long-term survival are the determining factors affecting the onset, disease process and outcome.

(1) Natural history of M. tuberculosis infection

After 3-8 weeks of infection, tuberculin (abbreviated as sputum) skin test turned to yang, 95% of the normal immune system of healthy people with normal immune syndrome disappeared, becoming a latent infection, about 5% in the future due to potential infection Re-ignition and onset.

(2) Host reaction and biological process of tuberculosis infection

The host's immune response to tuberculosis after tuberculosis enters the human body has special significance in its pathogenesis, clinical process and outcome.

Tuberculosis inhaled by droplets is engulfed by macrophages, and activated alveolar macrophages form early infection lesions. The initial growth of tuberculosis in macrophages forms a tuberculosis center with solid necrosis of cheese, which can limit the continued replication of tuberculosis. Cellular immunity and delayed type allergy mediated by T cells are formed at this stage. This will have a decisive impact on the evolution and outcome of tuberculosis.

The tuberculosis of most infected people in the symbiotic period is sustainable, the bacteria and the host are symbiotic, and the fibrous central part of the necrotic foci is considered to be the main place for the persistence of bacteria.

The cheese stove contains tuberculosis bacteria that grow but do not multiply. Once the cheese stove is liquefied, it provides an ideal breeding environment for the bacteria.

Tuberculosis prevention

Precaution

BCG vaccination against tuberculosis is mainly inhaled through the respiratory tract. Therefore, controlling air pollution is the key to preventing tuberculosis. Mainly take the following measures to prevent:

First, cultivate good hygiene habits.

Tuberculosis patients should cover their mouth with a handkerchief when coughing. It is best to spit the sputum on paper and burn it. The cup should be immersed in 2% coal phenol soap or 1% formaldehyde solution and sterilized in about two hours. Tuberculosis is the least resistant to damp heat and can be killed by boiling for 15 minutes. The patient's clothes, handkerchiefs, sheets, etc. are boiled and then washed. Mainly to prevent sputum contamination, 70% alcohol is most effective for daily disinfection, and tuberculosis is killed after 15-30 seconds of exposure. Milk must be sterilized by low temperature before it can be quoted.

1. Do a thorough disinfection. According to the characteristics of cold, heat and dry heat resistance of tubercle bacilli, boiled dishes, towels, clothes, handkerchiefs, masks and other items used by patients for 10 to 15 minutes; for books, quilts, chemical fiber clothing, etc. Cooked items can be exposed to sunlight for 4 to 6 hours or UV light for two hours. In addition, it can also be used for disinfection of disinfectant such as Sushui. The room where the patient lives can be sterilized by ultraviolet light.

2, regularly open the window to ventilate, keep the indoor air fresh. According to statistics, ventilation is ventilated every ten minutes, and after 4 to 5 times, 99% of Mycobacterium tuberculosis in the air can be blown off.

3, cultivate good hygiene habits, such as the implementation of the food system, washing utensils for special personnel, washing hands frequently, changing clothes, regular disinfection.

Second, regular lung health checks.

Regular lung health checks can detect early cases for timely treatment and prevention of dissemination. The health check should be conducted in conjunction with the local tuberculosis epidemic for 1-2 years. In the rural areas, lung examination should be carried out according to personal medical history, sputum examination and conscious signs, so as to find out in time and treat as soon as possible.

Third, BCG vaccination.

BCG is a live vaccine that is harmless to the human body and can produce immunity after multi-generation transfer of bovine tuberculosis in a special (including bovine bile) medium. In order to correctly determine whether vaccination is required, the sputum test is usually performed before vaccination, and the negative responder is vaccinated. However, allergic reactions have little effect on the body. In areas where the tuberculosis infection rate is very low, BCG can be directly inoculated without tuberculosis test. After 6-8 weeks of vaccination, the test of the sputum test antibody is positive, indicating that the human body has produced immunity; if the test is still negative, it means that the vaccination is not successful and needs to be vaccinated again.

Tuberculosis complications Complications, conjunctival tuberculosis, duodenal tuberculosis

Tuberculosis in different parts can cause different complications, see specific tuberculosis. There may be conjunctival tuberculosis, duodenal tuberculosis, etc.

Symptoms of tuberculosis common symptoms persistent low fever, fatigue, amenorrhea, dyspnea, hemoptysis, loss of appetite, chest pain, night sweats, low fever, low fever

Tuberculosis: There is a close history of TB contact, the onset can be urgent, mostly low fever (afternoon), night sweats, fatigue, anorexia, weight loss, female menstrual disorders, etc.; respiratory symptoms include cough, cough, hemoptysis, Chest pain, varying degrees of chest tightness or difficulty breathing.

Kidney tuberculosis: Bladder irritation is the most important, most important and earliest symptom of kidney tuberculosis. When Mycobacterium tuberculosis causes tuberculous inflammation in the bladder mucosa, the patient begins to have frequent urination, and the number of urination gradually increases during the day and night. It can be increased from several times a day to dozens of times. In severe cases, it should be urinated several times per hour until it can be Similar to urinary incontinence. 75% to 80% have frequent urinary symptoms. At the same time as frequent urination, urgency, dysuria, urination can not wait, must be discharged immediately, and it is difficult to bear. At the end of urination, there is a burning sensation in the bladder area of the urethra or the pubis. Bladder lesions are becoming more serious and the symptoms are more pronounced.

Bone tuberculosis: the initial local pain is not obvious, until the lesion develops to stimulate or oppress the adjacent nerve roots, such as the occurrence of intercostal neuralgia in lumbar tuberculosis; lumbar tuberculosis stimulates or oppresses the lumbar plexus nerve causing low back pain; simple bone tuberculosis or slip Membrane tuberculosis develops pain in the whole joint tuberculosis, which often causes the patient's attention. In order to relieve the pain, the muscles of the affected part are always in a state of paralysis, thereby providing protection. When the patient's position changes, especially when sleeping at night to lose muscle muscle protection, the pain is more obvious, and children often show nightingale.

Tuberculosis examination

Laboratory inspection

A tuberculosis test is the most specific method for the diagnosis of tuberculosis.

1. Sputum smear: sputum smear anti-acid staining is fast and simple, and the diagnosis of smear-positive tuberculosis can be basically established. However, with the increase in the incidence of non-tuberculosis mycobacteria in China, it needs to be ruled out.

2. Tuberculosis culture: In addition to understanding the growth and reproduction ability of tuberculosis, it can be used as a drug sensitivity test and strain identification. Tuberculosis grows slowly. It usually takes 4-8 weeks to report using Roche medium. Although the cultivation is time-consuming, but accurate and reliable, the cultured strains are particularly important for re-treatment of tuberculosis or tuberculosis suspected of being resistant.

3. Detection and identification of tuberculosis genes: Polymerase chain reaction (PCR) is used to amplify trace amounts of DNA. This method is quick and easy, and can identify bacterial types.

Film degree exam

Chest X-ray and thoracic CT are very important to find out the location, extent and nature of the lesions in the lungs. Especially the chest CT is important for finding small lesions or concealed lesions. At the same time, it can dynamically monitor the recovery of the lesion during the treatment.

Tuberculin test is a reference indicator for the diagnosis of tuberculosis infection. China's PPD (PPD-C) from human tuberculosis and BCG-PPD from BCG have good purity and have been widely used in clinical, intradermal injection. 0.1ml (5IU), 72 hours to observe the induration average diameter 5mm is positive, if the diameter 20mm, or local blister or necrosis is a strong positive reaction. A strong positive reaction often indicates active tuberculosis.

Other inspection

Severe tuberculosis patients may be associated with anemia, and severe tuberculosis may have leukopenia or leukemia-like reactions. ESR is common in active tuberculosis, but it has no diagnostic value. For patients with negative sputum, specific antibodies in serum have an auxiliary diagnostic value. Fiberoptic bronchoscopy is important for the detection of bronchial tuberculosis, the secretion of secretions, or for the detection of pathogenic or exfoliated cells and biopsy.

Diagnosis and diagnosis of tuberculosis

Diagnostic points

The diagnosis of tuberculosis requires comprehensive clinical manifestations, imaging features, and tubercle bacilli. For those who are positive for sputum, further identification and drug susceptibility testing are needed. Those with negative sputum need more auxiliary examinations, CT, fiberoptic bronchoscopy, serum. Antibodies, even biopsy, are necessary for diagnostic treatment.

Diagnosis of extrapulmonary tuberculosis

Various serous tuberculosis mainly combined with clinical manifestations, comprehensive analysis of night exudate test and other diagnostics. Tuberculous meningitis is comprehensively analyzed and judged according to the characteristics of subacute or chronic non-suppurative meningitis. Gastrointestinal X-ray and fiberoptic colonoscopy in patients with intestinal tuberculosis are helpful for diagnosis. The diagnosis of bone and joint and urinary tuberculosis is mainly based on clinical manifestations and imaging studies. Tuberculosis such as lymph nodes, liver, and spleen depends on the pathological examination of living tissues.

Differential diagnosis

The clinical and X-ray manifestations of pulmonary tuberculosis are similar to various non-tuberculosis diseases, and are easily misdiagnosed. Those with positive sputum bacteria are easy to diagnose, but it is necessary to identify non-tuberculous mycobacterial lung diseases by strain identification. For those with negative sputum bacteria, lung cancer, pneumonia, and lungs should be excluded. Abscess, bronchiectasis and other diseases.

Lung cancer: Lung cancer is more common in middle-aged and elderly people. The history of smoking is more common. There are often no obvious symptoms of tuberculosis, irritating cough, chest pain, progressive weight loss, and there are satellite lesions and calcifications on X-ray tuberculosis. Traces, burrs, chest CT can help identify the two, if necessary, can do fiberoptic bronchoscopy and lung biopsy, clinically difficult to rule out lung cancer, if necessary, can consider the thoracotomy.

Pneumonia: The formation of secondary pulmonary tuberculosis with rapid progression of disease is easily misdiagnosed as psoriasis caused by pneumococcal pneumonia. Pneumonia has multiple onset, high fever, chills, chest pain and rust stains. X-ray lesions are often limited. Single lung lobe, antibiotic treatment is effective. Caseous pneumonia has many symptoms of tuberculosis, slow onset, yellow mucus, X-ray lesions are mostly located in the right upper lobe, can involve multiple leaves, multiple segments, uneven density, can appear worm-like cavity, anti-tuberculosis treatment is effective.

Lung abscess: The cavity of the lung abscess is more common in the lower lobe of the lung. The inflammation around the abscess is more serious, and there is often a fluid level in the cavity. The tube above the cavity of the tuberculosis is more common, and there is less liquid level in the hole. In addition, the lung abscess has a rapid onset, high fever, a large amount of purulent sputum, no tuberculosis in the sputum, a significant increase in the total number of white blood cells and neutrophils, and antibiotic treatment is effective.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.