Abstract-Epidemics bursts have been sometimes observed in recent years, whose examples include, SARS (Severe Acute Respiratory Syndrome) and Ebola virus disease, and so on. For global companies which insure these epidemics, it is important and necessary to estimate the effect of events. Here we introduce a simple stochastic model for pricing such a kind of risks, which involves the Kermack-Mckendrick epidemic model combined with a stochastic trigger variable. The computations of our model are also given.Index Terms-Epidemic outbreaks, risk for an insurer, stochastic process, threshold theorem.