Fig. 3
Venn diagrams for the follow up of in-house interferon gamma release assay results. Distribution of interferon-gamma response conversion (a, b) or regression (c, d) at follow-up whole-blood (WBA) and long-term (LSA) stimulation assays. Recent close contact’s blood specimens were primed with Mycobacterium tuberculosis antigens (ESAT6:CFP10, PstS1/CFP10, and PstS1(285–374):CFP10). Each symbol represents one rCt from the respective follow-up group (Black square Group I TSTneg; Black diamond Group II TST convertors; Double dagger Group III TSTpos treated for latent tuberculosis infection (tLTBI); White triangle Group IV TSTpos not tLTBI; Black circle Group V TB incident cases)