Trump joins list of world leaders diagnosed with COVID-19

President Trump announced in a tweet on Friday that he and first lady Melania Trump have tested positive for the coronavirus. The tweet sparked a flurry of messages from other world leaders, including British Prime Minister Boris Johnson, who was diagnosed with COVID-19 himself back in March. CBS News foreign correspondent Charlie D'Agata joined CBSN with more on Johnson's battle with the virus and how the British government handled it.