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What news about tuberculosis?

  1. Gastroepato
  2. Pneumology
  3. What news about tuberculosis
  4. Therapy of tuberculosis
  5. Pleural effusion
  6. Exudative pleuritis
  7. Mediastinites, types
  8. Dyspnea, hunger for air
  9. Mediastinal syndrome

About a third of the world's population, including 11 million patients in the United States, have a latent infection with Mycobacterium tuberculosis. In Italy the problem of the immigration of people who come from weights where tuberculosis is endemic has created and will create noticeable problems of spreading the contagion. Suffice it to say that there is also the problem of the scourge of prostitution, the new trafficking of color slaves and, therefore, no one is more free from the risk of being infected with tuberculosis. Still it should be noted that the drugs are always less effective for the treatment.
In the United States, most cases of tuberculosis concern patients from countries where the disease is endemic. Infection is typically higher in economically disadvantaged populations and in immunosuppressed patients, and in people with AIDS. The problem is that the diagnosis must be promptly implemented, since delays in detecting and treating the infection facilitate its transmission. There are new techniques to make diagnoses that represent the overcoming of the old test to the tuberculin intradermoreation that shows a state of allergy towards the products of Koch's Bacillus, and / or the research of alcohol-resistant bacilli directly on the sputum, what very complex; it is the technique based on the release of interferon gamma and on the amplification of nucleic acids allow a more rapid and specific identification, respectively, of M. tuberculosis infection and the presence of an active disease.

In particular, with certainty, it can be stated that:

Screening for Mycobacterium tuberculosis infection should be conducted in selected patients, especially if exposed to a high risk of infection or progression to active disease. Tests based on antigen-specific gamma interferon release are useful for screening M. tuberculosis infection in patients previously vaccinated with Calmette-Guérin bacillus or with non-tuberculous mycobacterial infections. Isoniazid monotherapy is the treatment of choice for the majority of patients with latent tuberculosis infection, and should be sufficient except in cases of patients suspected of drug-resistant primary tuberculosis, for which the combination of multiple drugs and conducted therapies is indicated by direct observation.

Epidemiology

In 2007, 13.33 cases of active tuberculosis were identified in the United States. Although the number of cases continues to decrease, the rate of decline has slowed down. In the United States, subjects exposed to the highest risk of infection are those born in countries where M. tuberculosis infection is endemic; in these subjects the rates of infection are 10 times higher than those described in subjects born in the United States. Many of the ethnic and racial differences in the spread of active tuberculosis cases can be attributed to differences in prevalence among those born abroad or who present risk factors associated with a low socio-economic level. In 2007, 11.3% of US patients with active tuberculosis had a co-infection with human immunodeficiency virus (HIV). These data also represent sub-estimates, as they do not include California co-infection cases; In some cases of tuberculosis, no co-infection with HIV was also sought. Delays in the identification or treatment of patients with active pulmonary tuberculosis or patients with a high risk of reactivation of a latent tuberculosis infection facilitate the transmission of infection. Appropriate treatment of all patients with latent tuberculosis and active tuberculosis is essential for effective infection control.

New diagnostic tests

Causal screening for M. tuberculosis research is not a recommended procedure; instead a more targeted approach is indicated, which provides for the screening of subjects at high risk of latent tuberculosis infection or of progression towards an active infection. Patients with a latent infection and risk of progression to the active disease should be treated. The tuberculin skin test, also known as a Mantoux test or a purified protein derivative test, has been available for a long time and has the advantage of a limited economic cost. Despite the presence of problems such as poor sensitivity, low specificity and the risk of inadequate follow-up of the patient for reading the results, the tuberculin skin test is still the standard test for the diagnosis of M. tuberculosis infection.  False-positive test results can be caused by infections (with non-tuberculous mycobacteria, vaccination with the Calmette-Guérin bacillus (BCG) (particularly if recent), incorrect subjective interpretations of the test results (cure hardening). Guidelines in the United States do not provide, in the interpretation of test results, to take into account any vaccination with BCG, the new diagnostic tests are also able to distinguish between a recent vaccination with BCG and an infection M. tuberculosis: assays based on the interferon gamma antigen specific identify the release of gamma interferon by "memory" T cells previously sensitized by in vitro stimulation with specific proteins of M. tuberculosis.These tests do not generate false-positive results in patients previously vaccinated with the BCG strain or suffering from most mycobacterial non-tuberc infections olotiche; this allows greater specificity in the identification of M. tuberculosis. Like the tuberculin skin test, the assays based on interferon-gamma release simply identify M. tuberculosis; when used alone, therefore, these tests are not able to distinguish between latent infections and active infections. Moreover, with these tests, HIV infections and immunodeficiency conditions, which compromise T-cell function, can be responsible for false-negative or inconclusive results. Considered alone, therefore, a negative result in the tuberculin skin test or an examination based on the release of the interferon gamma is not able to exclude a diagnosis of tuberculosis.

New diagnostic tests

Immunodepressed patients (eg patients with diabetes, nephropathies, or terminals, silicosis, carcinomas, malnutrition, patients undergoing prolonged corticosteroid therapy, patients undergoing organ transplants, patients treated with tumor necrosis factor alpha inhibitors). The diagnosis of active tuberculosis is posed by a careful medical history and a complete physical examination, as well as by performing tests such as chest radiography, sputum or other tissue culture tests, and sometimes tissue biopsies. . When active tuberculosis is suspected. further diagnostic evaluations should be performed even before the results of the tuberculin skin test or of the interferon-gamma release assay are available. Several tests based on nucleic acid amplification methods allow us a faster and more sensitive diagnosis of active tuberculosis, and can be used as a complement to the smear for the research of acid-resistant bacilli and culture tests for mycobacteria.

Latent tuberculous infections

About a third of the world's population, including 11 million patients in the United States, have a latent infection with M. tuberculosis. In most immunocompetent patients the risk of activation of a latent infection over a lifetime is 5-10%. Modifications of "immunological fitness" diseases with immunosuppression (eg HIV infections, diabetes) can lead to an increase in this risk. Patients with HIV infection have a significantly higher risk of activation. The highest risk of development of an active tuberculosis concerns the first 2 years after the infection. Patients at high risk of reactivation should be adequately informed of the risks associated with reactivation, and should be strongly advised to undertake treatment of latent tuberculosis. In most patients with latent tuberculosis infection, the treatment of choice involves the administration of isoniazid; an exception is made by patients in whom resistance to the drug is suspected.

Treatment options for latent tuberculosis are listed A 9-month treatment with isoniazid decreases the rate of reactivation during granuloma dissolution, and is associated with rates of efficacy, in patients with good treatment compliance, of approximately 9 ° %. Nine months of isoniazid therapy are also indicated in patients with HIV infection and in children younger than 4 years; the treatment reduces the risks of therapeutic failure and development of resistance to drugs. Older age by itself is no longer an indication of exclusion from treatment. In patients who are unable or unwilling to undergo a 9-month treatment, 6-month isoniazid administration may be considered; the shorter treatment is however less effective. In patients with poor compliance and who are unable to take rifampicin, the short treatment with isoniazid may reduce the interruption rates of therapy, thus improving its effectiveness. Patient compliance with treatment can be a significant problem, particularly in those who have not fully understood the beneficial effects of the treatment itself. In patients who are unable to tolerate isoniazid or in patients with known or suspected tuberculosis isoniazid or in patients with known or suspected latent isoniazid resistant tuberculosis, alternative treatment involves the administration of rifampicin for 4 months. Compared to isoniazid administration for 9 months, rifampicin has lower hepatotoxicity, and higher treatment completion rates. However, a significant problem is the risk of drug interactions and development of resistance to rifampin in patients with poor compliance. In patients with HIV infection, who have a higher risk of rifampicin-resistant tuberculosis, rifampicin monotherapy is not recommended; there is also a risk of interactions between rifampicin and different therapies involving antiretroviral drug combinations.

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