Other forms: outbreaks
An outbreak is a sudden appearance of a disease in one place. An outbreak of measles, contain the outbreak, the outbreak spread.
The scale is what names it: an outbreak is local, an epidemic covers a region and a pandemic crosses continents. Finding the index case matters because the pattern of spread tells you how it moves. The word is out plus break, and it is old.
1nounoutbreakA sudden appearance of a disease in one place.
“An outbreak of food poisoning closed the school for a week.”
outbreak is an occurrence.
Old English utabrecan means to break out, from out plus break.
Old English
ūtābrecan — to break out
Middle English
outbreken
English, today
outbreak
From Middle English outbreken, oute-breken, from Old English ūtābrecan (“to break out”), equivalent to out + break. Cognate with stq uutbreeke (“to break out, burst out”), West Frisian útbrekke (“to break out”), Dutch uitbreken (“to break out, burst out”), German ausbrechen (“to break out, erupt”). The noun is cognate with stq Uutbreek (“outbreak”), West Frisian útbrek (“outbreak”), Dutch uitbraak (“outbreak”), and German Ausbruch (“outbreak”), and is comparable to Danish udbrud (“outbreak”), Faroese - and Icelandic útbrot (“rash”), Norwegian utbrudd (“outbreak”), and Swedish utbrott (“outbreak”).
Etymology from Wiktionary, CC BY-SA