index patient

noun

plural index patients

: an individual affected with the first known case of an infectious disease or genetically transmitted condition or mutation in a population, region, or family : index case sense 2

Examples of index patient in a Sentence

Recent Examples on the Web

The first girl to become sick—called the index patient—had used a bathroom where a grocery bag of snacks was being stored. —Sabrina Sholts, Smithsonian Magazine, 12 Mar. 2024

The index patient went home the next morning, but cookies, chips and fresh grapes in the grocery bag were passed around at the team’s lunch that afternoon. —Sabrina Sholts, Smithsonian Magazine, 12 Mar. 2024

Health authorities are still grappling with the puzzle of how the index patient in this outbreak, Ali, contracted the disease in the first place. —WIRED, 22 Sep. 2023

Used successfully to control Ebola outbreaks in Guinea and Sierra Leone, ring vaccination involves quickly inoculating close contacts of index patients, thereby shutting down a virus’s path to the general population. —Dan Werb, Time, 11 July 2023

Word History

First Known Use

1951, in the meaning defined above

Medical Definition

index patient

noun

: an individual affected with the first known case of an infectious disease or genetically transmitted condition or mutation in a population, region, or family : index case sense 2

called also index case-patient