McHenry County health officials adopt state, federal COVID-19 guidance for schools as key metrics worsen

McHenry County saw 74 new cases of COVID-19 per 100,000 residents Wednesday, after having been 37 per 100,000 residents one week earlier

McHenry County health officials aligned their guidance for reopening schools Monday with federal and state authorities, which reversed course last week and recommended everyone in school buildings wear masks regardless of vaccination status.

The recommendation of masks for all was made after the Centers for Disease Control and Prevention initially said, and the Illinois Department of Health concurred, that fully vaccinated students and school staff could choose not to wear facial coverings.

After the original guidance was issued in early July, many public school systems across Illinois, including in McHenry County, announced they intended to make wearing masks optional for all students and staff members, regardless of vaccination status.

The McHenry County Department of Health “has been meeting weekly with local superintendents, providing consultation regarding preventative strategies and metrics to determine community transmission in order to help them develop their own policies to assist in providing a safe educational environment,” it said in a news release Monday.

Among the metrics the county will be monitoring are the countywide seven-day incidence rate, or the number of cases per 100,000 residents. That metric rose to more than 74 as of Wednesday, the last date for which data is available, after having been about 37 one week prior, according to the dashboard.

An incidence rate of between 50 and 99.99 is categorized as indicating “substantial” COVID-19 transmission in the area, but the county remained in the “moderate” category Monday.

The CDC characterized McHenry County’s rate of COVID-19 transmission as “substantial” last week.

The McHenry County Department of Health uses a seven-day average “to better identify trends in transmission rates,” its spokeswoman said in an email to the Northwest Herald. She said the CDC uses daily rates and therefore could classify McHenry County at a different transmission level.

According to the CDC’s website, it calculates the incidence rate as the total new cases per 100,000 persons in the past seven days, which also is how the county describes its approach on its website.

The difference between the county’s approach and the CDC’s appears to be that the county requires a metric to have met the threshold for a higher level of community transmission at least seven of the last 10 days, according to the dashboard. The CDC’s methodology does not state that the threshold must be exceeded for a certain number of days before moving to the next category.

The county’s approach is meant to provide local officials and residents a better reflection of trends, McHenry County Department of Health spokeswoman Lindsey Salvatelli said.

The other key metric the county is gauging for its school recommendations is COVID-19 test positivity, measured by a seven-day rolling average. That rate was 6.6% as of Friday, meaning it indicates “moderate” transmission.

If the two statistics are indicating differing transmission levels, the higher level would be selected, both the McHenry County health department and CDC have said.

Additional considerations for schools being displayed on the county health department’s website for COVID-19 metrics and recommendations for schools are the percent increase in the number of cases in the county a week and the percent increase in the number of youth cases among people between age 3 and 18 a week.

The total number of cases was up 76% as of Friday in McHenry County and up 136% for youth cases, according to county data.

To view the county’s COVID-19 metrics for schools, go to

• Northwest Herald reporter Cassie Buchman contributed to this report.

Sam Lounsberry

Sam Lounsberry

Sam Lounsberry covers local government, business, K-12 education and all other aspects of life in McHenry County, in particular in the communities of Woodstock, McHenry, Richmond, Spring Grove, Wonder Lake and Johnsburg.