ST. LOUIS — St. Louis and St. Louis County on Wednesday banned social gatherings of more than nine or 10 people in an increasingly desperate bid to slow the rapid spread of the coronavirus, even as reports continued to pour in of new COVID-19 cases across Missouri and Illinois — and of Missouri’s first death from the virus.

The number of Illinois cases soared to 288 from 160 on Tuesday, said Gov. J.B. Pritzker, and included a new case in St. Clair County, bringing the total there to three.

Missouri Gov. Mike Parson announced that Missouri numbers had bounded upward, too, rising to 24 on Wednesday from 15 on Tuesday. Parson also reported the state’s first death: A resident older than 60 who lived in Boone County, home to the University of Missouri, who tested positive on Tuesday after recently traveling abroad.

“These numbers are going to change drastically and they’re going to change daily,” Parson said. “Everyone should stay at home. If you don’t need to be out right now, you should be staying at home.”

Three of the new cases were in the St. Louis metro area — one in St. Louis, one in St. Louis County and the first in St. Charles County — bringing the Missouri side of the region’s total to eight, including five in St. Louis County and two in St. Louis.