MEXICO CITY—Mexican President Andres Manuel Lopez Obrador continues to run the country despite having tested positive for COVID-19, his government said on Monday, as news of the infection threatens to undermine the towering role he has taken in public life. The 67-year-old Lopez Obrador, who has a history of heart problems and high blood pressure, said on Sunday evening he was being treated for mild symptoms of COVID-19. Subbing in for him at a regular daily news conference on Monday, Interior Minister Olga Sanchez said the president is feeling well and remains firmly in charge of the government. “He will recover soon,” she said. Although Lopez Obrador has vowed to keep working, he said for now he would step back from the 7 a.m. news conferences that have dominated political life since he took office in December 2018. Jose Luis Alomia Zegarra, a senior health ministry official, told reporters at …