The

basic reproduction number ([R.sub.0] of measles: a systematic review.

The analysis illustrates the impossibility of backward bifurcation in the Listeriosis model, because there is no existence of endemic equilibrium whenever the

basic reproduction number is less than one ([R.sub.0l] < 1).

So, to minimize the chances of a disease outbreak the intervention of control measures can be used such that the

basic reproduction number is kept below unity (i.e., [R.sup.0] < 1).

To do this, we will investigate appropriately all of the possible parameters about the effect of various parameters to reduce

basic reproduction number. [R.sub.0], close to one.

In this scenario, [R.sub.0] is exactly the

basic reproduction number of Pastor-Satorras and Vespignani model in [19].

Preliminary estimation of the

basic reproduction number of Zika virus infection during Colombia epidemic, 2015-2016.

The

basic reproduction number [R.sub.0] for system (3) can be obtained by using the method in [4].

Based on the practical meaning of the

basic reproduction number (Describes the number of people who are infected in the average infection period when an infected person is involved in all the vulnerable populations.

which implies that the

basic reproduction number can be decreased by increasing the efficacy of drug treatment.

The linear stability of [E.sub.0] is governed by the

basic reproduction number [R.sub.0] which can be found from the next generation matrix [19] for the system.

[R.sub.0] is the critical threshold of model (7) that is called the

basic reproduction number in the epidemic model.

The

basic reproduction number for this model is given by