The spread of infections (disease, ideas, fires, etc.) in a network (group of people, electronic network, forest, etc.) can be modeled by the evolution of states of nodes in a graph defined as a function of the states of the other nodes in the graph. Given an initial configuration of the graph with a subset of the nodes infected, a propagation function that specifies how the states of the nodes change over time, and a quarantine function that specifies the generation of regions centered on the infected nodes, from which the infection cannot spread; we identify and verify intervention policies designed to contain the propagation of the infection over the network. The approach can be used to determine an effective policy in such a scenario.