LTBI: A latent tuberculosis infection is not a disease. A latent infection with tuberculosis bacteria (abbreviated as LTBI) is an infection that has not (yet) led to tuberculosis, but in which a small number of tuberculosis bacteria remain in the body that can be controlled by the body's own immune system. The infected person is healthy and not infectious to those around them. If the immune system loses control of the tuberculosis bacteria, a latent infection can develop into tuberculosis. It is estimated that 5 - 10% of those infected will progress from latent infection to tuberculosis disease in the course of their lives. The highest risk of contracting the disease is in the first few years after infection.
Definition: A latent tuberculosis infection is by definition present if a blood test (IGRA) or skin test (THT) is positive and tuberculosis has been ruled out. In addition to the clinical examination, at least one inconspicuous X-ray examination of the lungs is required.
Preventive therapy / chemoprevention: Preventive therapy can prevent the progression from infection to tuberculosis. However, as only 5 - 10% of people with a latent infection fall ill, prevention is only offered if the risk of developing the disease is increased or if there has been intensive contact with someone with infectious tuberculosis. The treating physicians or the public health department will provide individual and detailed advice on this so that each latently infected person can individually weigh up whether the expected benefit outweighs the risk of side effects from preventive therapy. Various treatment options are available for preventive therapy. Individual treatment risks and interactions with other medications should be checked before each preventive therapy.
Chemoprophylaxis: A distinction is made between prevention and prophylaxis. In the case of prophylaxis, preventive treatment is started for people with a particularly high risk of contracting the disease (especially children under the age of 5) if the initial blood or skin test is negative. If the test remains negative, treatment is stopped after two to three months. Tuberculosis must also be ruled out before starting prophylaxis.
Dosage: The dosage is also adapted to the body weight in preventive therapy. The dosage calculators for children and adults can also be used to select the medication for preventive therapy. The treatment plan and follow-up checks must be determined individually for preventive therapy. If preventive therapy is not an option or is not desired, follow-up checks are carried out over at least one year, often longer, depending on the individual risk.