ethods. Tuberculin skin testing is a method of screening for exposure to TB infection. A person who was infected with TB will have developed a hypersensitivity to the TB bacteria even if they did not develop the disease. A purified protein derived from the bacteria is injected into the skin. The skin area is inspected 48 to 72 hours later for a bump. A positive test implies that TB infection has occurred. Skin tests are not 100 percent accurate and they do not always indicate the presence of active disease.Continue article... Diagnosis of TB disease is established by the identification of the bacteria in sputum (matter coughed up from the lungs) or other body fluids and tissues in conjunction with an abnormal chest X ray and the presence of TB symptoms. Once TB has been diagnosed, further testing is required to determine which drugs would be most appropriate to treat the particular strain of TB bacteria.Detecting the presence or the strain of the TB bacterium was once a time-consuming process that would often delay therapy. Today, the use of genetic engineering techniques greatly reduces the time required for diagnosis. A new technique is the polymerase chain reaction (PCR), which can rapidly duplicate a tiny amount of bacterial hereditary material from a small sample of infected sputum. IV. Treatment and Prevention Print section General preventive measures can be taken to reduce the spread of TB in public places. Ventilation systems lessen the chance of infection by dispersing the bacteria. Ultraviolet lighting also reduces, but does not eliminate, the threat of infection by killing TB bacteria in confined spaces. Vaccines, such as the bacillus Calmette Guerin (BCG) vaccine, prepared from bacteria that have been weakened, are another preventive measure. The BCG vaccine is most effective in preventing childhood cases of TB.With the advent of effective antibiotics for TB, drug therapy has become the cornerstone of treatment. Single-drug ...
