Fig. 11.

(a) Solution trajectories of system (10) illustrating the existence of locally asymptotically stable TB endemic equilibrium ${\chi }_T^1$ with ${\mathcal{R}}_E^T=0.3948<1$, ${\nu }_2=0.000355>{\overline{\nu }}_2$, (b) visualization of backward bifurcation in $S_U^T-L-T_T$ space. Other parameters are at the same values as in Table 1