Comment on: "Epidemic spreading on heterogeneous networks with identical infectivity" - [Phys. Lett. A 364 (2007) 189]

In [R. Yang, et al., Phys. Lett. A 364 (2007) 189], it has been introduced a network-based Kermack-McKendrick-like SIR epidemic model, in which each node shows an identical capability of contact A and in which it has been claimed that, on scale free networks, the value A(-1) would be a threshold value for the density of recovered individuals. We show here that the recovered individuals cannot follow the claimed threshold behaviour. Furthermore, we give a biologically sound threshold ruling the transitory dynamics of the epidemics. (c) 2007 Elsevier B.V. All rights reserved.