FILE - In this Wednesday, March 25, 2020 file photo Britain's Prime Minister Boris Johnson leaves 10 Downing Street for the House of Commons for his weekly Prime Ministers Questions, in London. British Prime Minister Boris Johnson has tested positive for the new coronavirus. Johnson's office said Friday March 27, 2020 that he was tested after showing mild symptoms, Downing St. says Johnson is self-isolating and continuing to lead the country's response to COVID-19. (AP Photo/Matt Dunham, File)