Brazil’s health minister resigned Friday after less than a month on the job in a sign of continuing upheaval over how the nation should battle the coronavirus pandemic, quitting a day after President Jair Bolsonaro stepped up pressure on him to expand use of the antimalarial drug chloroquine in treating patients. Dr. Nelson Teich, an oncologist and health care consultant, took the job April 17 faced with the task of aligning the ministry’s actions with the president’s view that Brazil’s economy must not be destroyed by restrictions to control spread of the virus. Teich’s predecessor, Luiz Henrique Mandetta, also had...