"IN YOUNG CHILDREN, the risk of progression from latent tuberculosis infection (LTBI) to active tuberculosis (TB) is inversely related to age; without specific treatment, approximately one half of infants and one fifth of older children develop active TB up to 2 years after infection. In particular, children 4 years of age fail to contain the spread of intracellular pathogens as a consequence of an impaired T-cell response. Therefore, this age group is considered a priority in the strategies to control TB worldwide." (source)
Using the standard treatment for LTBI does not allow for the existence of drug resistant bacterium; in this article
Pediatrics. 2009 Mar;123(3):902-3. practioners call for revised treatment guidelines
CONCLUSION: Because of the high prevalence of isoniazid resistance, rifampin should be considered for children with latent tuberculosis infection originating from countries with >11% isoniazid resistance.
Without monitoring treatment to ensure full eradication of the bacterium the risk of extending drug resistance remains.
