Tuberculosis is a highly contagious disease caused by the microbial micobacterium tuberculosis. The source of infection is a sick person, animal or bacterial carrier.
Interpreting the result
If the child has not yet been infectedmycobacteria, the reaction will be negative, and this tubercle will not change in color and size. In such a case, such a child will be revaccinated during adolescence. A positive tuberculin test is considered, if 72 hours after the injection of the drug infiltrate is equal to or more than 5 mm. In this case, it can be hyperemic or remain the same color. Also, the response to a tuberculin test may be questionable or hyperergic, with a more accurate assessment by a phthisiatrician. He also accepts children who have been diagnosed with tuberculosis, such patients are to be observed with him and treatment with special medications. To select schoolchildren for the revaccination of BCG, a tuberculin test is also used. Assessment of it is necessary, first of all, to determine the degree of immune activity of the body and protection from mycobacteria. The same is assessed when the vaccine is administered, that is, by the scar on the shoulder formed after BCG. In fact, the stronger the immunity of the child, the more pronounced will be the skin trail after it.
Sensitivity of the method
As the tuberculin sample is madeintracutaneously, it is quite sensitive to external factors. However, contrary to the widespread myth that it can not be drenched with water, it can still be done, only it is undesirable to use aggressive detergents, as well as rubbing the skin with a washcloth or combing it. All this can result in a false positive result. More sensitive, including water, is Pirke's scarification method by applying a skin scratch, which along with Mantou was performed earlier for the diagnosis of tuberculosis. However, at present it is used much less often.</ p>>