The United States lost 15,000 people to COVID-19 last week, the deadliest seven days since April, and health officials warned that the worst is yet to come. The number of new coronavirus cases rose 19% to 1.4 million in the week ended Dec. 6, after falling the previous week as many testing centers were closed for the Thanksgiving holiday, according to a Reuters analysis of state and county reports. Rhode Island and Indiana had the highest number of cases per capita, with more than 700 people diagnosed for every 100,000 residents.