US president Donald Trump has tested positive for Covid-19, confirming in a tweet on Friday that he and his wife, Melania, both have the virus. In a note released to the media, Trump’s doctor, Navy Commander Dr. Sean Conley, said that Trump and his wife “are both well at this time, and they plan to remain at home within the White House during their convalescence” but Business Insider reports that at 74 years old, Trump faces a higher risk of serious complications. He also meets the technical threshold for obesity, which some studies suggest is also a comorbidity. Dr Jonathan Reiner, professor of medicine at The George Washington University Medical Centre, meanwhile told CNN that Biden, who shared a stage with Trump during the debate on Tuesday, will have to be tested too.