Quantifying relative virulence: when fails and AUC alone just is not enough.

A challenge in virology is quantifying relative virulence () between two (or more) viruses that exhibit different replication dynamics in a given susceptible host. Host is often used to mathematically characterize virus-host interactions and to quantify the magnitude of detriment to host due to viral infection. Quantifying using canonical parameters, like maximum specific growth rate (), can fail to provide reliable information regarding virulence. Although area-under-the-curve (AUC) calculations are more robust, they are sensitive to limit selection. Using empirical data from Sulfolobus Spindle-shaped Virus (SSV) infections, we introduce a novel, simple metric that has proven to be more robust than existing methods for assessing . This metric () accurately aligns biological phenomena with quantified metrics to determine . It also addresses a gap in virology by permitting comparisons between different non-lytic virus infections or non-lytic versus lytic virus infections on a given host in single-virus/single-host infections.