LONDON (Reuters) – Queen Elizabeth, the world’s longest reigning monarch, tested positive for COVID-19 on Sunday. Buckingham Palace tries to avoid releasing details about her health as it says medical matters are private. * COVID: “The Queen has today tested positive for COVID,” Buckingham Palace said. “Her Majesty is experiencing mild cold like symptoms but expects to continue light duties at Windsor over the coming week.” “She will continue to receive medical attention and will follow all appropriate guidelines,” the Palace said. * “I can’t move” – Elizabeth on Feb. 16 quipped to members of …