IFNG and infection: Figure 3 shows the proportion (%) of animals that were test positive pre- and post-M. bovis infection (weeks 40 to 65). In the absence of BCG vaccination (Figure 3A), the IFNG test detects ~40% of infected cattle at 2 weeks post-infection compared to ~10% using the Enferplex test (no IDEXX-positives at this time point).