case fatality rate

noun

variants or case-fatality rate or less commonly case fatality ratio or case-fatality ratio

plural case fatality rates or case-fatality rates also case fatality ratios or case-fatality ratios

: the ratio between deaths and confirmed or reported cases of a specific disease or medical condition within a given time period

The 1918-19 influenza pandemic, one of the most severe in history, … is generally estimated to have had a case fatality rate of more than 2.5%.

—John Woolfolk

If untreated, the case-fatality rate of inhaled anthrax exceeds 80%.

—The Journal of the American Medical Association

—abbreviation CFR

Examples of case fatality rate in a Sentence

Recent Examples on the Web

But the floor on fire (deep below the street level) houses CCHF, or Crimean-Congo hemorrhagic fever, which is described by the World Health Organization as a virus that causes severe viral hemorrhagic fever outbreaks with a case fatality rate up to 40 percent. —Patrick Gomez, EW.com, 10 Apr. 2025

The historical record of known H5N1 cases offers a harrowing case fatality rate of about 50% among humans. —Will Stone, NPR, 19 Mar. 2025

In previous outbreaks, Sudan virus disease has had a case fatality rate between 41% and 70%, according to WHO. —Jen Christensen, CNN, 6 Feb. 2025

Of those, 464 were fatal, for a case fatality rate of 49 percent. —Ars Technica, 18 Dec. 2024

Malaria is not generally known to have a particularly high case fatality rate. —Joshua P. Cohen, Forbes, 17 Dec. 2024

Three of the patients from South Africa have died, leading to a case fatality rate of 12.5%—far higher the 0.2% seen in the global outbreak. —Byjon Cohen, science.org, 13 Aug. 2024

Word History

First Known Use

1912, in the meaning defined above

Rhymes for case fatality rate

• aluminosilicate
• isothiocyanate
• abate
• airfreight
• await
• baseplate
• berate
• birthdate
• birthrate
• bookplate
• borate
• breastplate

Medical Definition

case fatality rate

noun

variants or case-fatality rate also case fatality ratio or case-fatality ratio

: the ratio between deaths and confirmed or reported cases of a specific disease or medical condition within a given time period

Among the immunocompetent patients who had invasive pneumococcal infections caused by serotypes represented in the vaccine, the case fatality rate was 33 percent (23 of 70) among those who had been vaccinated and 25 percent (186 of 738) among those who had not.

—Eugene D. Shapiro et al., The New England Journal of Medicine

An estimated 10,000 to 15,000 cases of invasive group A streptococcal infections occur each year in the United States; of these, necrotizing fasciitis occurs in five to 10 percent, and the case-fatality rate is 28 percent.

—Harvey B. Simon, Scientific American Medicine

—abbreviation CFR