OTTAWA—Canadian Foreign Minister Melanie Joly said on Monday a rapid COVID-19 test that she had taken proved to be positive, adding she was working in isolation until the result could be confirmed. Joly, 42, was named foreign minister in October and would be one of the most prominent domestic politicians to come down with the coronavirus, which is spreading rapidly as the Omicron variant picks up speed. “I have taken a rapid test and tested positive for COVID-19. Following public health guidelines, I am in isolation and will continue my work virtually, as I have been for a number of days, until I get the results of my PCR test,” she tweeted. Joly did not give further details. Her chief spokeswoman was not immediately available for comment. Prime Minister Justin Trudeau said on Friday a spike in cases of Omicron was “scary,” while a top medical official suggested the healthcare …