Axios Des Moines: Des Moines may reinstate a mask policy if cases continue to escalate, Mayor Frank Cownie warned during a City Council work session Tuesday. Iowa averaged around 505 new COVID cases per day in the last week, according to The New York Times tracker. That’s more than double the average two weeks ago. Polk County reported a seven-day average of 105 new cases on Tuesday, up by 159% from two weeks ago. When Des Moines’ municipal masking ended on Feb. 28, Iowa was averaging around 474 new daily cases, and Polk County about 101.