'The sun had already set on March 7 when Nooh Pullichalil Bava received the call. “I have bad news,” his boss warned. On February 29, a family of three had arrived in the Indian state of Kerala from Italy, where they lived. The trio skipped a voluntary screening for covid-19 at the airport and took a taxi 125 miles (200 kilometers) to their home in the town of Ranni. When they started developing symptoms soon afterward, they didn’t alert the hospital. Now, a whole week after taking off from Venice, all three—a middle-aged man and woman and their adult son—had tested positive for the virus, and so had two of their elderly relatives...'