“…Developments of SIR models and their extensions continue to be employed to describe various scenarios in mathematical epidemics, cf. Murray [32], Wang and Mulone [41], Wang and Ruan [42], Wang and Zhao [43], Boni and Feldman [5], Lou and Ruggeri [24], Buonomo and Lacitignola [6], Capone [9], Keeling and Rohani [20], Li et al [23], Ma and Li [25], Buonomo and Rionero [7], Buonomo et al [8], Mulone et al [31], Rionero [34], Rionero and Vitiello [35].…”