Patch network (IMAGE) Society for Industrial and Applied Mathematics Caption Path network that represents the spread of pathogens along a river. 1 is the most upstream location and 5 is the most downstream. There is a bypass from 2 to 4 that could be caused by flooding. Credit Figure courtesy of Stephen Kirkland, Zhisheng Shuai, P. van den Driessche, and Xueying Wang. Usage Restrictions Use with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.