The COVID-19 pandemic has made clear the importance of understanding precisely how diseases spread throughout networks of transportation. In a paper publishing on Thursday in the IAM Journal on Applied Mathematics, Stephen Kirkland (University of Manitoba), Zhisheng Shuai (University of Central Florida), P. van den Driessche (University of Victoria), and Xueying Wang (Washington State University) study the way in which changes in a network of multiple interconnected communities impact the ensuing spread of disease.