Eighteen young people tested positive for COVID-19 in Sangamon County during the week of August 23.
The weekly number of new cases among those less than 20 years old in each county is one of four metrics the Illinois Department of Public Health began publishing late last month to assist local schools and health departments in making decisions about in-person learning.
The numbers on the health department’s website are labeled “Metrics for School Determination and Community Spread.” The rest of the metrics are the same data the department has been providing about counties – the positivity rate, new COVID-19 cases and new cases per hundred thousand people.
The health department also published guidelines (PDF) to help school districts and local health departments in interpreting the data.
Springfield School District 186 Board President Scott McFarland said one complaint during the debate about how to begin the school year was the lack of public health data. The board decided to conduct the first quarter almost completely online and reevaluate the decision at the end of September.
He said schools can limit the spread of COVID-19 in their buildings with mask wearing and social distancing, particularly if the district alternates students attending school in-person two days a week.
“We can't control the spread outside of our schools. So determining where that is, is going to be a big factor in when we can move into a hybrid model to have some students in the classroom,” McFarland said.
Dr. Vidya Sundareshan is an infectious disease specialist with SIU School of Medicine and an advisor to the Sangamon County Department of Public Health. She said the new cases among people younger than 20 give a good picture of the spread of the virus.
“Reporting the youth cases separately is definitely a good indication of what's really happening in the community and in terms of community transmission,” she said. “That's more relatable to what's happening in the schools.”
IDPH also provides guidelines for how to interpret the data. It recommends that significant changes in the data or numbers that reflect moderate to substantial community transmission should prompt a discussion between school and public health leaders about changing learning method, including moving all classes online.
The guidelines outline what is minimal, moderate and substantial community transmission, which closely follow the guidelines for county officials. For example, one metric for moderate transmission is the rate of new cases for the county that is higher than 50 cases per 100,000. Another is an increase in the number of new youth cases of more than 10 or a more than 20% increase for two weeks.
IDPH tracks the data on a weekly basis and releases the numbers Friday for the week prior. The most recent update is for the week of August 23. The health department began releasing the data that week as well, according to spokeswoman Melaney Arnold.
“We recognize that there are some qualitative events/challenges that will occur locally which must be considered with any change in the level of transmission and prompt an Adaptive Pause (time taken to plan, prepare, and respond),” she said in a written statement. An “adaptive pause” could be delaying the start of a semester or moving learning online for a district or particular grade or school building, according to the guidance. “The local health department will provide guidance to school officials and the Illinois State Board of Education concerning these metrics.”