Just a few weeks ago, Puerto Rican officials were encouraging more tourism from the US mainland. Now COVID-19 cases on the island have spiked, and the governor has had to roll back reopening efforts. Dr. Andrés Juliá Beltrán is an epidemiologist working to contain the spread of the virus in the city of Yauco. He tells The World’s Marco Werman that Puerto Ricans returning home from Florida and Texas are driving up coronavirus caseloads.