(WKOW) — Only a week ago, when the Center for Disease Control first announced new mask recommendations, no southern Wisconsin county was yet in a concerning place for COVID-19 transmission.
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At that time, only two counties had "high" transmission risk and nine had "substantial" transmission risk. This equates to about 15% of Wisconsin's 72 counties impacted by CDC guidelines.
In only a week, the number of counties in high or substantial transmission levels has changed significantly. Now, 10 counties have high transmission — including Milwaukee and all the surrounding counties. Another 34 counties have substantial transmission, including a significant portion of southern Wisconsin.
This means that now 61% of Wisconsin counties are subject to CDC masking and other COVID-19 guidelines to prevent the spread of the Delta variant.
Of 27 News' viewing area, five counties have gone from moderate to substantial transmission: Dane, Rock, Columbia, Sauk, and Marquette.
Watch a time-lapse of the changes in transmission level over the course of a month in the CDC Data Tracker video below.