patient zero

== English == === Alternative forms === patient 0 === Etymology === Originally patient O (standing for out of California), referring to Gaëtan Dugas, a superspreader of AIDS who was at the time erroneously believed to have introduced the virus to the United States. The letter O was later misinterpreted as a zero. === Noun === patient zero (plural patient zeros or patient zeroes or patients zero) (epidemiology) The initial patient in the population of an epidemiological investigation. Synonym: index patient Hypernym: patient Coordinate terms: proband (in genetic investigations); index case (loosely synonymous); patient under investigation (figuratively, informal) The source or origin of something. ==== Translations ====