REFERAT ENGLEZA: TUBERCULOSIS

label Referate autorenew 2025-09-29, 16:56 history_edu Anonim
TUBERCULOSISCaractherizeCauses and colony sTransmision & trethmentTuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually attack the lungs. But, TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal. The cause of tuberculosis, Mycobacterium tuberculosis (MTB), is a slow-growing aerobic bacterium that divides every 16 to 20 hours. MTB is identified microscopically by its staining characteristics: it retains certain stains after being treated with acidic solution, and is thus classified as an "acid-fast bacillus" or AFB. In the most common staining technique, the Ziehl-Neelsen stain, AFB are stained a bright red which stands out clearly against a blue background. Acid-fast bacilli can also be visualized by fluorescent microscopy, and by an auramine-rhodamine stain. Tuberculosis is classed as one of the granulomatous inflammatory conditions. Macrophages, T lymphocytes, B lymphocytes and fibroblasts are among the cells that aggregate to form a granuloma, with lymphocytes surrounding infected macrophages. The granuloma functions not only to prevent dissemination of the mycobacteria, but also provides a local environment for communication of cells of the immune system. Within the granuloma, T lymphocytes (CD4+) secrete a cytokine such as interferon gamma, which activates macrophages to destroy the bacteria with which they are infected, making them better able to fight infection. The radiography is one of the most important analisis in the TB diagnosisIt showes the principals regions of the lungs- in this case , wich are afectted.TB is spread by aerosol droplets expelled by people with active TB disease of the lungs when they cough, sneeze, speak, or spit. Each droplet is 5 micrometre
m in diameter and contains 1 to 3 bacilli. Close contacts (people with prolonged, frequent, or intense contact) are at highest risk of becoming infected (typically a 22% infection rate). TreatmentFor all practical purposes, only patients with tuberculosis of the lungs can spread TB to other people. People may become infected with TB but not have active disease: such people are said to have latent TB infection (LTBI) and are not capable of passing the infection on to other people. The reason for treating people with LTBI is to prevent them from progressing to active TB disease later in life (approximately 10% lifetime risk). The distinction is important because treatment options are different for the two groups.Tuberculosis vaccineThe first recombinant tuberculosis vaccine entered clinical trials in the United States in 2004 sponsored by the National Institute of Allergy and Infectious Diseases (NIAID).[2]A 2005 study showed that a DNA TB vaccine given with conventional chemotherapy can accelerate the disappearance of bacteria as well as protecting against re-infection in mice; it may take four to five years to be available in humans.[3]Because of the limitations of current vaccines, researchers and policymakers are promoting new economic models of vaccine development including prizes, tax incentives and advance market commitments.