Once we establish a positive TST result and have ruled out active disease thru a chest x-ray and systems check, we determine whether they're a good candidate for INH therapy by their early release date. If they have enough time to complete 9 months of treatment, and agree to take the meds and to monthly bld draws we'll treat. Pills are direct observed therapy only and have to be dispensed at the medication window while the nurse and officer watch to make sure they're taken. We tend to be pro treatment. I haven't encountered active TB yet, and feel we have a good survelliance program in place. We use quanteferon gold occationally because of false positive and negative TST results. Hope that helps.