Varying time frames for isolation for those who have tested positive for covid. Between 14 days (Germany) to 5 (USA). This, despite knowing some people will be infectious for 12 days.
I must admit, when I was present for an outbreak in my place of employment, I wasn't happy being asked to work 121 with people on their 11th day after a positive covid test.
www.theguardian.com/world/2021/dec/28/how-long-are-people-infectious-for-with-covid-and-how-do-isolation-rules-vary
What slang do you remember school teachers using?


