Epidemiologists quantify the lethality of pathogens in two primary ways. The infection fatality rate (IFR) is the probability a person will die if he or she gets infected. The case fatality rate (CFR) is the probability a person will die after being diagnosed with the condition by a health-care provider. Sometimes an alternative for the CFR is used, the symptomatic case fatality rate (sCFR), which is the probability that a person will die if he or she simply shows symptoms of the infection.
