Risk for TB Among Close Contacts of Patients with Active Disease?

Prior studies have estimated that the lifetime risk for tuberculosis (TB) in individuals with latent Mycobacterium tuberculosis infection (LTBI) is between 5% and 10% and that approximately half of these cases occur within the first 2 years after exposure.

To update and better understand the risks and timing of TB among those recently exposed, investigators conducted a prospective study using data from nine health departments in the U.S. and Canada on 4490 persons who were close contacts of adults with culture-positive pulmonary TB. Contacts were cross-matched with state and provincial TB registries at the end of the enrollment period and annually for up to 4 years to ascertain who had developed active TB and when the infection occurred.

Duri…