Recently, it has been demonstrated using mathematical modeling in the context of dengue that it is possible to generate outbreaks even in cases when R 0 v1 provided that the vector-tohuman component of R 0 is greater than one and that a certain number of infected vectors are introduced into the affected population [45] . However, it has been demonstrated that the index case was a man of Indian origin from Kerala living in Castiglione di Cervia, without history of traveling during the previous year [1] . He only reported contact with a relative of his, who had arrived in Italy on June 21 2007 from Kerala, India (a region of India affected by the CHIKV epidemic), and visited him (see Eq. 6 and 7). e As a but for the basic reproduction number. f As c but by assuming reference interventions, resulting in the following reductions: 40% as for breeding sites and eggs, 90% as for larvae and 95% as for adults. doi:10.1371/journal.pone.0018860.g004