The Mantoux test has long established itself as the main method of research for the presence of tuberculosis. This immunological test can show the presence of a tubercle bacillus in a child’s body. Everyone remembers the days when they made manta in school and kindergarten, gave appropriate recommendations - not to wet or scratch for 3 days. At the end of this time, the doctors measured the "button". Based on its size, there was an assessment of the reaction of the organism.
Vaccination Mantoux: what happens?
The principle of the reaction is very simple. Small doses of tuberculin - an antigen, which is obtained from the destroyed Koch sticks (causative agents of tuberculosis), are subcutaneously injected into the child's body, and then the doctors monitor the local reaction of the body. Tuberculin itself does not contain Koch's wand, it contains only the products of its vital activity!
In the place of injection, a local specific inflammation reaction occurs, which is caused by T-lymphocytes. This group of lymphocytes is the blood cells that are responsible for anti-tuberculosis immunity. But not all T-lymphocytes are involved in the reaction to the introduction of tuberculin, but only those who have already “got acquainted” with mycobacterium tuberculosis. If the child’s body is already “familiar” with this bacterium, then there are more such lymphocytes, respectively, the inflammation will be more extensive, and the reaction of the Mantoux test is positive. Simply put, a positive reaction to a manta test indicates that the inflammation exceeds the natural reaction that is caused by the injection itself.
Parents should prepare their child for this test. First of all, the reaction should be carried out before any vaccinations, it is also worth paying attention to the diet, completely eliminate all obviously allergenic products. Manta is sampled annually, starting at 12 months of age. And after 72 hours, from the moment of vaccination, dimensions are measured - the diameter of the "button". The result shows the intensity of immunity against the tubercle bacillus. The rate in children is determined by the doctor.
The size of the seal itself is measured, the appearance of red does not indicate the presence of immunity to tuberculosis, or, conversely, infection. In fact, the more bacteria in the child’s body, the stronger the immune response, respectively, the “button” the more. Then it can be concluded that the risk of getting sick is big.
Until the test results are monitored, it is strictly forbidden to allow skin contact and the injection site with water; this area should not be combed. Otherwise, the results will be unreliable. Mantoux test is not a vaccination! This is a specific reaction of the body, which allows you to identify a predisposition to the disease. And even if the baby is released from preventive vaccinations for some reason, the test should be carried out, and the rate determined by the doctor.
There are many factors to consider when evaluating results. It is difficult to call reliable indicators if the baby has a predisposition to allergies or the test was carried out at the time of seasonal allergies. The body's reaction to the manta test is similar to the allergic one, and the existing allergy will give a positive result, with almost a 100% guarantee. In addition, the results in the presence of skin diseases, acute and chronic diseases in the relapse stage will be considered unreliable.
Excluding all these diseases and causes, the true response of the sample can be of 3 types. Negative, that reaction is considered when, after the injection, there are no reactions - seals, redness. And the "button" itself does not exceed the size of 1 mm. Such a reaction indicates that Koch’s sticks have never entered the body at all. But at the same time, a negative reaction can be observed with the development of tuberculosis in persons with immunodeficiency, and if infection and the development of pathology occurred during the last week. The reaction can be called a “button” no more than 4 mm, or only redness occurs. at the injection site.
A positive reaction is the appearance of a seal with a size of 5–16 mm. The appearance of such a reaction indicates a child’s immunity against tuberculosis. In such a case, the evaluation of the results takes a long time, over several years. And on the basis of these multi-year results, the doctor will assess whether the child has been infected with tuberculosis.
Hyperargic reaction is carried out in a separate category when the size of the "button" exceeds 17 mm or if there are pushes or ulcers together with the injection. Such a reaction will speak about the ingestion of a large number of mycobacteria in the body and infection with tuberculosis, but there are exceptions.
What can affect the reaction?
Sample results can be controversial, and in some cases, children rework the sample. But completely excluding those factors that may affect the inaccuracy of the results.
Since the reaction to injected tuberculin is allergic, associated allergic diseases can affect the final result, and not in a positive way. For these reasons, initially it is necessary to stop the allergic reaction, to achieve remission, and only then repeat the test. If the child has seasonal allergies, the date of the test is transferred to a more favorable time.
In addition, chronic pathologies in the acute stage, a recent infectious disease, can affect the results of the test. It is necessary to take into account the individual sensitivity of the skin. When evaluating results in adolescents, especially girls, it is necessary to build on the menstrual cycle.
A mantoux test can be positive or doubtful in the presence of helminthic invasions in a child’s body. For these and many more. For other reasons, the presence of a positive reaction to tuberculin does not always indicate infection and illness of the child.
Vaccination Mantoux: photo
To obtain reliable results, it is important not only to prepare the child - temporarily eliminate all obviously allergenic products from the diet, discuss with the doctor a temporary cessation of taking certain medications, etc. It is important to tell the doctor about the presence of allergies in the child and other related diseases. Only with the observance of all security measures, it will be possible to get reliable results. And even if they turned out to be positive, this does not always indicate a disease.