Tuberculosis (TB) is a chronic, progressive infection which is often characterized by a lag phase after the primary infection. TB affects the lungs most often. Symptoms include a productive cough, fever, weight loss and malaise. The diagnosis is usually made Sputumabstriche and culture and, increasingly, through rapid molecular-based diagnostic tests. The treatment is always carried out by a combination of various antituberkulotischer drugs which are administered for at least 6 months.

Tuberculosis (TB) is a chronic, progressive infection which is often characterized by a lag phase after the primary infection. TB affects the lungs most often. Symptoms include a productive cough, fever, weight loss and malaise. The diagnosis is usually made Sputumabstriche and culture and, increasingly, through rapid molecular-based diagnostic tests. The treatment is always carried out by a combination of various antituberkulotischer drugs which are administered for at least 6 months.

(For perinatal tuberculosis, perinatal tuberculosis (TB).) Tuberculosis (TB) is a chronic, progressive infection which is often characterized by a lag phase after the primary infection. TB affects the lungs most often. Symptoms include a productive cough, fever, weight loss and malaise. The diagnosis is usually made Sputumabstriche and culture and, increasingly, through rapid molecular-based diagnostic tests. The treatment is always carried out by a combination of various antituberkulotischer drugs which are administered for at least 6 months. TB is one of the world most common infectious cause of morbidity and mortality represents and led in 2012 to about 1.3 million deaths, mostly in low- and middle-income. HIV / AIDS is the most important factor that predisposes to TB infection and increased mortality in the case of HIV / TB co-infection, especially in the parts of the world where both infections are common. Etiology The term refers TB in the strict sense only to diseases caused by Mycobacterium tuberculosis (for the people is the most important reservoir are) caused. Occasionally similar diseases caused by the closely related mycobacteria M. bovis, M. africanum and M. microti are caused, which are grouped together-with M. tuberculosis than M. tuberculosis complex referred to as the Mycobacterium tuberculosis complex. The main reservoir of pathogens are people who are suffering from infectious capable open tuberculosis of the lungs: TB occurs almost exclusively by inhalation of airborne particles (infectious droplets) concluded that contain M. tuberculosis. This spread mainly by coughing, singing and other forced breathing maneuvers of individuals with active TB from a significant amounts of the pathogen in sputum containing (typically enough to be positive in microscopy or in the more sensitive culture). People with pulmonary cavernous lesions are due to the high number of bacteria contained in a lesion, be regarded as particularly infectious. Infectious droplets (particles with a diameter of <5 ?) containing tubercle bacilli can remain suspended for several hours in the air, which increases the risk of their spread. However, if these droplets are once sedimented onto a surface, it's unlikely these pathogens as respirable, infectious microparticles (eg itself. by sweeping the floor or shaking out of bed) to resuspend. Although the dust particles resulting from such action contained potentially viable tubercle bacilli, but are too large to reach the alveoli, what would be necessary to initiate an infection. The contact with carrier objects (eg. As contaminated surfaces, foods and personal respirators) does not seem to favor the spread. How contagious patients with untreated active pulmonary tuberculosis, is very different. Certain strains of M. tuberculosis are contagious and patients with positive Sputumabstrichen are more contagious than those who have positive results only in the culture. Patients with a cavernous disease (which is closely linked to a mycobacterial stress of the sputum) are more virulent than those without. Environmental factors are also important. The transmission takes place preferably by frequent or persistent exposure to untreated patients, spread a large number of tubercle bacilli in overcrowded, poorly ventilated, enclosed spaces. Thus, people who live in poverty or in closed institutions, particularly at risk. An increased risk for healthcare workers in close contact with diseased active cases. Thus, assessments of the risk of infection vary considerably; some studies suggest that only 1 of 3 patients infects with untreated pulmonary tuberculosis any close contacts; WHO estimates that each untreated patient can infect 10 to 15 people per year. However, most people who are infected develop no active disease. The risk of infection decreases rapidly once an effective treatment begins; the organisms are less infectious, even if they remain in the sputum, and cough decreases. Studies of household contacts indicate that the transferability within 2 weeks after patients begin an effective treatment ends. Much less it comes to infection by pathogen-bearing aerosol formation by flushing infected wounds, in mycobacteriological laboratories or in autopsy rooms. TB of the tonsils, lymph nodes, abdominal organs, bones and joints used to be common through the consumption of milk or dairy products (eg cheese.) Caused contaminated with M. bovis - however, these routes of transmission are in the developed world by slaughtering been largely eliminated from the skin test tuberculin positive cows and pasteurization of milk. Tuberculosis caused by M. bovis still occurs in developing countries and among immigrants from developing countries where bovine tuberculosis is endemic (eg. As some Latin American countries). The increasing popularity of cheese, which is made from unpasteurized milk, raises new concerns, when the cheese from countries with bovine tuberculosis problem (z. B. Mexico, United Kingdom) comes. Epidemiology Approximately one-third of the world's population is infected (based on tuberculin skin test). Of the infected people, perhaps 15 million have active disease at a defined time. In 2011, an estimated 8.7 million new TB cases occurred (125 / 100,000) worldwide. About 5.1 million of these cases occurred in Asia and about 2.2 million in Africa. The disease rates vary greatly depending on the country, age, ethnicity, gender and socioeconomic status. India and China report the largest number of new cases, but South Africa has probably also by the high coincidence of HIV / AIDS the greatest incidence rate of TB:, 000. The infection rate decline (for drug-susceptible TB), and mortality 993/100. New cases decreased between 2010 and 2011 by 2.2%, which is a trend continues, which has occurred in recent years. These trends are likely to partially attributed to global efforts to control TB, which have more people allows access to drugs against TB and HIV infection. In the US, the number of cases has decreased for 20 consecutive years. In 2012 9.951 cases to the CDC reported - an incidence rate of 3.2 / 100,000, which represented a decrease of 6.1% compared to 2011 and a record low (in the range of 0.4 to 10 in West Virginia, 2 in Washington DC). More than half of these cases occurred in patients who were born outside the United States in areas of high prevalence. The TB rate in the United States among foreign-born persons (15.8 / 100,000) was 11.5 times as high as among those born in the US persons (1.4 / 100,000). Among US-born people 37% of the disease cases were in people with darker skin color. In the southeast of the country and in urban centers across the US poor US-born people wear with dark skin, the homeless, prisoners and other disenfranchised minorities disproportionately to the disease rate. Within these high-risk populations, the disease rates can approach the maximum rates in other parts of the world, even in low TB prevalence country United States. In parts of the United States and other industrialized countries occurred between 1985 and 1992 to a renewed increase in TB cases. This has been associated with various factors related, including HIV co-infection, homelessness, deteriorating structures of public health services and the appearance of multi-resistant TB pathogen (MDR-TB). Despite major control measures by the effective public health service and hygiene measures relevant institutions seems the problem of MDR-TB outbreaks, including the extremely drug-resistant TB (XDR-TB) - the pathogen to spread more and more around the world, which is favored by inadequate resources, including diagnostic and therapeutic delivery systems. In most parts of the world drug resistant TB can not be quickly diagnosed and treated promptly with effective treatments, including effective use of medication second choice. This situation leads to an ongoing transmission, low cure rates and increased resistance. The treatment of XDR-TB (XDR = Extended Drug Resistance: All important standard anti-tuberculosis have no effect or only partially) shows even less positive results; the mortality rate is extremely high in patients with HIV, even if they are treated with antiretroviral drugs. An effective treatment and management of adverse events, public relations and social support have more favorable in some regions, led declining epidemiological trends in drug-resistant TB (z. B. Peru, Tomsk region of Russia). In India and China will only just begun to implement national MDR-TB programs, and the future of MDR-TB could be strongly influenced by the success or failure of these programs. Pathophysiology M. tuberculosis bacilli cause a primary initial infection that leads to unusual cases of acute illness. Most (about 95%) primary infections are asymptomatic and are followed by a latent phase, remain in the dormant mycobacteria intracellular inactive to decades ( "dormant persisters"). A variable proportion of latent infection is reactivated later with signs and symptoms of the disease. Infection is not generally transferable in the primary phase, and is never contagious in the latent stage. Primary infection An infection from inhaling particles requires that are small enough to pass through the mucociliary clearance of the upper respiratory tract and be deposited deep in the lungs, usually in the subpleural air spaces of the middle or lower lung. Larger droplets tend to get stuck in the more proximal airways and therefore do not lead usually to infections because they can be excreted from there before they have infected target cells. Infection is usually made from a single infectious droplets, which usually carries only a few organisms in it. only one organism can possibly be sufficient to cause infection in susceptible individuals, but less susceptible people repeated exposure may be necessary to develop an infection. To initiate an infection, M. tuberculosis bacilli must be absorbed by alveolar macrophages. The bacilli that are not killed by the macrophages, replicating within them and eventually kill the "host macrophages" (later also with specific immunized CD4 lymphocytes of the host); Inflammatory cells are attracted to this area and cause focal pneumonia, which coalesce into a characteristic and histologically detectable tubercle. In the first weeks of infection, some infected macrophages pass into regional lymph nodes (hilar z. B., mediastinal) from where they enter the bloodstream. The pathogen then könnn be hematogenous in any parts of the body spread, especially in the apical-posterior portions of the lung, epiphysis of the long bones, kidneys, vertebrae and meninges. Hematogenous dissemination in patients with partial immunity less likely by vaccination or prior natural infection with M. tuberculosis or environmental mycobacteria. In 95% of cases the immune system suppressed after about 3 weeks unhindered proliferation bacterial DNA replication usually even before the development of symptoms or complaints. Bazillenherde in the lungs or other sites can be organized to epithelioid granulomas that can caseate central necrosis. Tubercle bacilli can survive for years, the balance between the resistance of the host and microbial virulence determines whether the infection eventually will heal without treatment, latent remains or becomes active again in this material. The granuomatösen of infection can leave little or consolidation areas (Ghon stoves) fibronoduläre scars in the lung peaks of one or both lungs (Simon Peak herd, resulting from another site of infection usually made hämatogem seeding). A Ghon stove with lymph node involvement is a Ghon complex, which, if it is calcified, as Ranke complex is referred to. The tuberculin skin test (tuberculosis (TB) skin test) and interferon-gamma release blood test (IGRA) are positive during the latent stage of infection. The locations of the latent infection are dynamic processes, not entirely dormant, as was once believed. More rarely, the primary outbreak spreads immediately and leads to an acute illness with pneumonia (sometimes cavernous), pleural effusion and significant enlargement of mediastinal or hilar lymph nodes (which can also compress the bronchi in children). Small pleural effusions are primarily lymphocytic characteristically contain only a few pathogens and disappear within a few weeks. This sequence may occur more frequently in young children and recently infected or newly infected immunocompromised patients. Much less common than pulmonary TB can exceptionally also a primary extrapulmonary TB can manifest anywhere on the body without evidence of pulmonary involvement. The most common extrapulmonary lung involvement is the TB lymphadenopathy; However, the most feared due to high mortality in the very young and very old people tuberculous disease Meningitis.Aktive Healthy persons infected with TB have a lifetime risk of about 5-10%, of developing active disease, although the percentage much depends on the age and other risk factors. In 50-80% of those who develop active disease TB is reactivated within the first two years of the disease, but this can happen only decades later. The reactivation can start from any initial affected organ, but it is most common in the lung peaks instead, presumably because of the favorable local conditions such. As a high O2 tension. Ghon herd and affected hilar lymph nodes are rarely the starting point of reactivation. Conditions that cellular immunity (which is essential for defense against TB) affect the reactivation greatly facilitate. Thus, patients with HIV co-infection, an annual risk of about 10% for the development of active disease. Other conditions that favor reactivation, but to a lesser extent than HIV infection, are diabetes, head and neck cancer, gastrectomy, jejunoileal bypass surgery, dialysis-dependent chronic kidney disease and significant weight loss. Drugs that suppress the immune system, also favor the development of active TB. Patients who require immune suppression after organ transplantation, have the highest risk, but other immunosuppressive agents such as corticosteroids and TNF inhibitors often lead to reactivation. Tobacco use is also a risk factor. In some patients developed active disease if they become infected again rather than when a latent disease is reactivated. Reinfection is the probable mechanism in regions where TB is prevalent and patients are exposed to a large inoculum of bacilli. The reactivation of latent infection predominates in low prevalence areas. In a present patients, it is difficult to determine whether an active disease from re-infection or reactivation results. TB damages the tissue by a characteristic delayed hypersensitivity reaction (DTH type IV), which often leads to a histologically granulomatous caseating necrosis. Just the presence of pulmonary lesions characteristic. but these are not always cavernous, especially not in immunocompromised patients with DTH. Pleural effusions are not as common as in the case of a progressive primary TB, but may be the result of direct or hematogenous spread. The rupture of a large tuberculous lesion in the pleural space may lead to an empyema with or without bronchopleural fistula and sometimes cause a pneumothorax with simultaneous connection to the bronchial system. In the pre-antibiotic time a medically induced therapeutic pneumothorax was occasionally complicated by empyema, which usually led to death, just as a sudden massive hemoptysis due to the erosion of a pulmonary artery during the destructive expansion of the cavernous process. The clinical course of the disease varies considerably depending on the virulence of the pathogen and the status of host defenses. The course can develop isolated with members populations (eg. As Native Americans) who were not exposed unlike many Europeans and their American descendants for centuries a selection pressure innate or natural immunity to the disease, its rapidly. The course is often indolent in European and American populations. Rare acute respiratory syndrome (ARDS) can develop after a diffuse hematogenous spread or rupture of a large cavern with distribution in the lungs, which is seen as a result of hypersensitivity to TB antigens. Symptoms and complaints With an active pulmonary TB, even if they are moderate or severe, it may be that patients are not groundbreaking symptoms except non-specific reduction of well-being, loss of appetite, fatigue and weight loss, which develop gradually over several weeks. Special vigilance should be exercised if, in addition also characteristic symptoms: The most common cause coughing. Initially, this may be only minimally productive, with yellow or green sputum, mostly in the morning after getting up, the cough but can be more productive with progressive disease. The hemoptysis occurs only with cavernous TB (due granulamatösen damage in the blood vessels, but sometimes due to fungal growth in a cavern). Characteristically, there is - if at all - only mild fever (old clinical description, therefore, for example, as "cold" abscess). Night sweats more pronounced (i. E .: pronounced durchnässendes night sweats, sometimes several times in one night) is a classic symptom. but it is neither frequent nor specific for TB. Due to damage to the lung parenchyma, a spontaneous pneumothorax or pleural effusion TB can cause of dyspnea. In HIV co-infection, the clinical picture is often atypical. Because the DTH is impaired, cavernous and exudative manifestations are rare, for example. It is also likely that patients symptoms of extrapulmonary or disseminated disease. Extrapulmonary TB causes various systemic and localized manifestations that depend on the affected organs (extrapulmonary tuberculosis). Diagnostic chest X-ray Acid fast stain and culture tuberculin skin test (TST) or interferon-gamma release detection (IGRA) When available, nucleic acid-based testing often suspected of having pulmonary TB, due to the chest x-ray images (for evaluation of respiratory symptoms cough> 3 weeks, hemoptysis, chest pain, dyspnea), an unexplained illness, FUUs were made, or of a positive tuberculin skin test (tuberculosis (TB): skin test) or a IGRAs that during Kontaktinvestigation was carried out as a screening process or the like. The suspicion of TB is higher in patients who have fever, cough that lasts> 2 to 3 weeks, night sweats, weight loss and / or lymphadenopathy have and (in patients with possible TB exposure z. B. over infected family members, friends or other Contact persons; institutional exposure, travel in TB-endemic areas). The initial tests are a chest x-ray image and a sputum and culture. When the diagnosis of active TB after imaging of the chest cavity and the sputum is still unclear, a TST or IGRA may be performed. Nucleic acid-based tests (eg., PCR) may be diagnostic. Tuberculosis (Röntgentorax) ZEPHYR / SCIENCE PHOTO LIBRARY var model = {thumbnailUrl ‘/-/media/manual/professional/images/m2700245-tuberculosis-chest-x-ray-science-photo-library-high_de.jpg?la=de&thn = 0 & mw = 350 ‘, imageUrl’ /-/media/manual/professional/images/m2700245-tuberculosis-chest-x-ray-science-photo-library-high_de.jpg?la=de&thn=0 ‘, title:’ tuberculosis (Röntgentorax) ‘, description:’ u003Ca id = “v37896068 ” class = “”anchor “” u003e u003c / a u003e u003cdiv class = “”para “” u003e u003cp u003eKavitäre lesion of right upper lobe on a chest x-ray of a patient with tuberculosis u003c / p u003e u003c / div u003e. ‘credits’ ZEPHYR / SCIENCE PHOTO LIBRARY’

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