[Risk factors of tuberculosis in children].

In order to better target children who should be screened for tuberculosis and to tailor treatment according to risk a good knowledge of the risk factors for latent tuberculosis infection and progression to disease is needed. Risk of infection is strongly related to number and duration of exposure and is particularly high when contact happens at home. Host factors like a young age or chronic underlying disease seem to favor progression to disease but do not increase infection rate. Some M. tuberculosis strains seem to be more easily transmissible. An adaptation of the criteria for a positive tuberculin skin test according to risk may help to increase the positive and negative predictive values of the test. When the risk of progression to disease is high a prophylactic treatment may be considered.