Resonance and epidemics.

<p>Deterministic (black line) and stochastic (red dots) profiles for the amount of infected host, no immigration. A) The transmission rate <i>β</i> is constant,i.e. no variable disease control is applied (brown line at the top of the figure). B) Resonance mechanism. Here we impose a wave-form transmission rate <i>β</i> with the same mean as in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002870#pcbi-1002870-g006" target="_blank">Figure 6.A</a> (brown line at the top of the figure). This mimics the case when a periodic control is applied. When the frequency of the variable control is close to the natural frequencies of the pathosystem, the amplitudes of the stochastic uctuations dramatically increase.