In just one month, the number of new coronavirus cases in South Dakota has gone down significantly. Some of the most dramatic changes are in areas with mask mandates.

South Dakota is seeing fewer positive COVID-19 tests each week. In the last month the number of new people tested has also declined. But that’s not the only factor that’s influencing the numbers.

When it comes to masks, Brookings took the lead. It was the first city to enact a mandate in South Dakota.

“I do think it’s had a positive impact,” Brookings city council member Nick Wendell told KELOLAND News on December 3rd.

In mid-November three more of South Dakota’s larger cities enacted mandates. Huron was first, followed by Mitchell.

“We’ve had high numbers, we’ve had a lot of deaths, in the city, and, you know, no matter which side of the coin you’re on, that’s an issue,” said Mayor Bob Everson about the decision.

A Sioux Falls mandate took effect at midnight on November 21st.

SDSU Epidemiologist Bonny Specker has been tracking the numbers and says those four mandates appear to be making a difference.

“What is interesting is what happened with the seven-day running averages of new cases per day in the 10 counties with the most populous cities based on whether the largest city passed, or did not pass, a mask mandate before December 1st, a time that changes should be apparent by mid-December,” Specker said in an email.

She says Brookings, Beadle, Davison and Minnehaha Counties saw a 69 percent decrease in cases between November 15 and December 14. She says the six counties without a mask mandate before December 1 saw a 40 percent decrease.

The numbers appear to show masks and mandates make a difference, which is something doctors have been saying for weeks.

“Every week to month, we’re getting more and more studies that are supporting the current mask mandates and that are showing, you know, how effective they actually are in shutting down the transmission. And so the science is definitely there and pretty clear,” Dr. David Basel told KELOLAND News in November.

Specker says Brookings County, which is home to the city with the state’s first mandate, also had one of the lowest rates of new cases per day per 100,000 population for the entire month of November.