Tag: diseases and immunity

BCG, or bacille Calmette-Guerin, is a vaccine for tuberculosis (TB) disease. The BCG vaccine is made from a weakened form of a bacterium closely related to human TB. The vaccine is 70-80% effective against the most severe forms of TB, such as TB meningitis in children.

The Mantoux tuberculin skin test (TST) or the TB blood test can be used to test for M. tuberculosis infection. The Mantoux tuberculin skin test is performed by injecting a small amount of fluid called tuberculin into the skin in the lower part of the arm. The test is read within 48 to 72 hours by a trained health care worker, who looks for a reaction (induration) on the arm. A posterior-anterior chest radiograph is used to detect chest abnormalities in TB. Lesions may appear anywhere in the lungs and may differ in size, shape, density, and cavitation. The presence of acid-fast-bacilli (AFB) on a sputum smear or other specimen often indicates TB disease.  A positive culture for M. tuberculosis confirms the diagnosis of TB disease. 

BCG vaccine provides immunity or protection against tuberculosis (TB). The vaccine may be given to persons at high risk of developing TB. When used to protect against TB, it is injected into the skin. 

Tuberculosis (TB) is a bacterial disease cased by Mycobacterium tuberculosis. Though TB typically attacks the lungs, it can also target the kidney, spine and brain. Once the bacteria is spread, Mycobacterium tuberculosis grows in the throat and lungs after two to eight weeks after infection. It then can either be fought off entirely by the immune system, remain in the body in a latent state, or develop into active TB. If it is active TB, it can then become skeletal TB, genital tract TB, urinary tract TB, CNS TB, gastrointestinal TB, adrenal TB or cardiac TB. The tissue damage results from the lymphoid cells releasing toxic substances rather than from bacterial toxins. The bacteria actually cause macrophages to form granulomas. These granulomas can liquefy and cause bacteria to spill into the lungs to cause large  cavities to form active TB. The bacteria breed in the cavities. Thus, the tissue destruction results from cell-mediated hypersensitivity.

Latent TB is the condition in which you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. Latent TB, also called as an inactive TB or TB infection, isn't contagious. It can turn into active TB, so treatment is important for the person with latent TB and to help control the spread of TB in general. 

Tuberculosis is treated with isoniazid, rifampicin, pyrazinamide and ethambutol or streptomycin. Rifampicin is a broad spectrum antibiotic and hence can prevent other bacterial infections also. Rifampicin serves as the potent inhibitor of bacterial RNA synthesis. 

Latent TB is the condition in which you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. Latent TB, also called as an inactive TB or TB infection, is not contagious. It can turn into active TB, so treatment is important for the person with latent TB and to help control the spread of TB in general.

Symptoms of active TB can depend on what part of the body has been infected. If active TB occurs in the lungs, the symptoms can include a cough lasting 3 weeks or more, pain in the chest area, breathing difficulty, weight loss, cough that brings blood or mucus, chills, fever, and fatigue. TB can also affect a person's brain, bones, kidneys, or spine.

Chemoprophylaxis is the method of administrating medicines for preventing disease. It is also called as Chemoprevention. Tuberculosis chemoprophylaxis is used to prevent the infection or it is also used to avoid development of disease in a person who is having latent TB. Isoniazid drug is most commonly given as a preventive measure. 

Extrapulmonary TB refers to TB that occurs in areas outside the lungs, such as the lymph nodes, bones, or abdomen, therefore it does not primarily affect the lungs.