An epidemiology term that quantifies the chances that a person who contracts an infection from a pathogen, will die from it.
Deeper dive
Not everyone who is infected by a pathogen will show symptoms of a disease. Not everyone who is infected by a pathogen will die.
Knowing the IFR helps scientists determine the danger of a particular pathogen and develop countermeasures to prevent its transmission. With pathogens, like the SARS-CoV-2 virus that causes COVID-19, the exact IFR rate has been difficult to determine because most people who aren’t sick aren’t being tested for infection. Therefore, scientists have been more closely tracking observed case fatality rates (the chances of someone with a confirmed COVID-19 case dying from it). The observed case fatality rate from COVID-19 varies by region because some countries have less robust medical resources than others.
For example, as of August 2022, Peru’s observed case fatality rate from COVID-19 was 5.3 percent, compared with the United States, which has a case fatality rate of 1.1 percent, according to Johns Hopkins University & Medicine Coronavirus Resource Center.