Table 4

IFN-γ and antibody test combinations and sensitivity and specificity valuesa

Test combinationVL alpacas (n = 48)TB-free alpacas (n = 257)
n/48% sensitivity95% CIn/257% specificity95% CI
IFN-γ + Stat-Pak4593.887.0–1005279.274.2–84.2
IFN-γ + Idexx4491.783.9–99.55578.673.6–83.6
IFN-γ + DPP4491.783.9–99.55877.472.3–82.5
IFN-γ + Enferplex4593.887–1005877.472.3–82.5
IFN-γ + Stat-Pak + Idexx4810092.6–1005777.872.7–82.9
IFN-γ + Stat-Pak + DPP4810092.6–1006076.771.5–81.9
IFN-γ + Stat-Pak + Enferplex4797.993.8–1006076.771.5–81.9
IFN-γ + Idexx + DPP4593.887.0–1006275.970.0–81.2
IFN-γ + Idexx + Enferplex4491.783.9–99.56275.970.0–81.2
IFN-γ + Enferplex + DPP4797.993.8–1006574.769.4–80
  • a IFN-γ positive, PPDB-PPDA > 0.1 or EC-nil > 0.1.