Letters warning of a “confirmed case of measles” were sent to parents of various Yellowknife schools on Sunday evening.

Initially, families at St Patrick High School and Weledeh Catholic School reported receiving an advisory that exposure occurred at St Pat’s – including areas shared with Weledeh – from 8am till 5:40pm on each of April 28, April 30 and May 1.

“All persons present at this venue during the time period are considered to be exposed and must follow public health guidance,” read the letter, issued by the NWT’s chief public health officer, Dr Kami Kandola.