Figure 2.

General structure of the dynamic transmission model for an intervention cluster in the Thibela TB randomized controlled trial among South African gold miners, 2006–2011. Because of high levels of transmission in the miners, all gold miners were assumed to have been infected at least once in their lifetime, which accounts for the absence of an uninfected compartment. The dashed lines reflect activities relating to case finding or isoniazid preventive therapy. The arrows out of the compartments, which have no destination, reflect out-migration or death. The small arrows into the compartments, which do not start from any destination, reflect in-migration. The shaded boxes reflect people who are taking IPT. IPT, isoniazid preventive therapy; s−c+, smear-negative, culture-positive; s+c+, smear-positive, culture-positive; TB, tuberculosis.