Ninety-one percent of COVID-19 tests came back positive in Rock County, according to the daily update Thursday from the Rock County Health Department.

The 91% rate is the highest percentage positivity rate for the county to date and well above the state seven-day positivity rate of 20.8%.

Rock County continues to have escalating postivity rates for COVID-19 as the new cases in Illinois reached 4,015 and new cases in Wisconsin reached 3,747.

While the number of school-age children testing positive is increasing countywide, it’s still a fraction of the total number of cases.

Rates of COVID-19 have continued to increase since the beginning of September as schools reopened. Between Sept. 1 and Oct. 13, 192 school-aged children (age 4 to 17) contracted COVID-19, which marks a 40% increase from 137 school-aged kids who tested positive over the five months from April to August, according to information from Rock County Epidemiologist Nick Zupan. There have been a total of 2,791 COVID-19 cases in Rock County between Sept. 1 and Oct. 13.

Although the number of school-aged children with COVID-19 is increasing, it’s still a low percentage of the total positive cases in the county. According to municipal data from the health department on Monday, in Beloit 7% of positive cases are among those under age 15, and 17% are ages 15-24. In Janesville, 7% of positive cases are among those under age 15, and 21% of cases are in 15-24-year olds.

On Thursday, the Rock County Health Department reported 96 new cases of COVID-19 from the previous day and no additional deaths in Rock County, bringing the countywide total to 3,634 cases and 37 deaths.

The health department estimates 39,475 people have tested negative and 2,576 people have recovered. There were 1,030 active cases as of Monday. The positivity rate, or those whose tests were positive, was 91%, the highest to date.

Dane County reported 12,072 cases and 46 deaths; Green County reported 760 cases and 3 deaths; and Walworth County reported 2,989 cases and 36 deaths, Wisconsin Department of Health Services (DHS) data from Thursday shows.

Wisconsin reported 3,747 new cases and 17 additional deaths on Thursday, bringing the statewide total to 162,325 cases and 1,553 deaths. As of Thursday, 127,576 people have recovered in the state and DHS believes there are a total of 33,160 active cases in Wisconsin.

As of Thursday, the Winnebago County Health Department reported 293 new cases and 1 additional death, bringing the countywide total to 8,247 cases and 161 deaths. Winnebago County had a positivity rate of 11.4%.

Boone County reported total 1,527 cases and 24 deaths; DeKalb County reported 1,984 cases and 42 deaths; McHenry County reported 5,310 cases and 119 deaths; Ogle County reported 964 cases and 6 deaths; and Stephenson County reported 732 cases and 7 deaths, state data shows.

On Thursday, The Illinois Department of Public Health (IDPH) reported 4,015 new cases in Illinois, including 53 additional confirmed deaths. Currently, IDPH is reporting a total of 331,620 cases, including 9,127 deaths, in 102 counties in Illinois.