If a person is diagnosed with latent tuberculosis infection (LTBI) and is at risk of developing active disease, preventive treatment is recommended. This is the case, for example, if you have recently been in contact with a person with infectious tuberculosis, have a chronic immunocompromising disease or are taking medication that impairs the immune system, such as TNF-alpha inhibitors. Preventive therapy can significantly reduce the risk of contracting tuberculosis. Like tuberculosis therapy, it must be taken over a longer period of time, but fewer drugs are used. This preventive treatment is also known as preventive therapy or chemoprevention.
Before starting preventive therapy, an X-ray examination of the lungs must be carried out to rule out pre-existing tuberculosis. Sometimes further examinations are also necessary.
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Children under the age of 5 fall ill more frequently and more severely than adults after a tuberculosis infection. For this reason, chemoprophylaxis is started after close contact with a person with infectious tuberculosis. However, LTBI tests (e.g. tuberculin skin test or IGRA), which are intended to determine whether the child has become infected, only provide a reliable result 8 weeks after contact. The test is therefore repeated after 8 weeks and treatment is then only continued if an infection is detected.
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Preventive therapy is not mandatory, as a latent infection does not yet mean illness and is not contagious. If there is an increased risk of contracting the disease, preventive treatment can significantly reduce the likelihood of developing tuberculosis. The decision as to whether preventive treatment makes sense should be made together with experienced doctors or the public health department.