COVID-19 spread in McHenry County now ‘substantial,’ McHenry County Department of Health says

CDC began categorizing community transmission of COVID-19 as ‘substantial’ last week, leading to recommendation that everyone wear masks regardless of vaccination status

The spread of COVID-19 in McHenry County is “substantial,” the McHenry County Department of Health reported Wednesday, recommending that everyone in McHenry County follow the Centers for Disease Control and Prevention guidance and wear a mask indoors regardless of vaccination status.

“As the delta variant is becoming the predominant variant circulating in Illinois, wearing a mask indoors, even if fully vaccinated, will help reduce the spread of the disease. This is especially important for those with underlying medical conditions or weakened immune systems,” McHenry County Public Health Administrator Melissa Adamson said in a statement. “We are asking everyone to consider how their actions may impact others as community transmission of COVID-19 is on the rise.”

The change in characterization Wednesday now aligns the county with how the CDC have been categorization the level of community transmission for McHenry County.

The key difference between the two public health agencies is that when moving to a higher transmission level, the county requires a metric to be above that threshold for seven out of the past 10 days, a requirement the CDC does not have.

The incidence rate – the number of new cases per 100,000 residents – met the threshold for “substantial” transmission seven of the last 10 days Wednesday, triggering the change in categorization.

McHenry County saw about 81 new cases per 100,000 residents as of Friday, the last day data is available for, according to the county’s dashboard.

The other metric used to measure community spread is the positivity rate, measured by a seven-day rolling average, 6.8% as of Sunday, the last data data is available. It has been above the “moderate” threshold for six of the past 10 days.

The McHenry County health department also reported 32 new COVID-19 cases Wednesday. That brings the total to 29,913, including 299 deaths and 30 deaths in which the cause was likely COVID-19 but could not be confirmed.

The county’s recovery rate remains at 99%.

Meanwhile, about 250 more McHenry County residents now are fully vaccinated, bringing the total to 155,828, or about 50.5% of residents, the Illinois Department of Public Health reported Wednesday.

Vaccinations, on average, have been on the rise for the last week with 320,770 doses total administered to McHenry County residents, state data shows.

Statewide, 73.1% of those age 12 and older have received at least one vaccine dose, the IDPH reported as of Wednesday. That rate is 75% for those 18 and older and 91.7% for those 65 and older.

Vaccination “is not the only tool to slow community transmission of the virus but is the strongest preventative measure available,” according to the release Wednesday from the McHenry County health department, advising residents they can find a vaccination location near them by going to vaccines.gov.

Businesses and organizations can also request to hold a vaccine clinic by completing the ”Request A Clinic Form” available on the county health department’s COVID-19 Vaccine Locations website. Questions can be directed to the county COVID-19 Call Center at 815-334-4045.


The IDPH reported 2,364 new confirmed and probable cases of COVID-19 across Illinois on Wednesday, and another 115 new hospital admissions were reported for Sunday, the IDPH reported.

As of late Tuesday, Illinois had 1,165 total COVID-19 patients in the hospital, twice as many as just more than two weeks ago and the most since May 28. Of those, 246 were in intensive care units, and 94 were on ventilators.

McHenry County’s positivity rate, as measured by a seven-day rolling average, increased to 6.8%, the highest it’s been since the beginning of May. Data remains on a three-day lag. The rate for Region 9, which is composed of Lake and McHenry counties, rose to 5%.

Region 9 had 29% of its ICU beds available as of Wednesday, and the state reported hospital admissions related to COVID-19 increased nine out of the past 10 days.

Statewide, the IDPH reported 1,430,265 cases, 23,476 confirmed deaths and 2,484 probable deaths. Neighboring Lake County’s health department reported 63,109 cases and 1,030 deaths through Tuesday, and to the south, Kane County’s health department reported 60,415 cases and 817 deaths on Wednesday.

Among McHenry County ZIP codes, Crystal Lake (60014) has the highest number of COVID-19 cases with a total of 4,599 confirmed cases, according to county data. Woodstock (60098) follows with 3,481 cases.

The McHenry County health department reports ZIP code data only for parts within McHenry County, a department spokeswoman said. Any discrepancies between county and IDPH numbers likely are because of the data’s provisional nature and because each health department finalizes its data at different times, she said.

The following is the rest of the local breakdown of cases by ZIP code: McHenry (60050) 3,142; Lake in the Hills (60156) 2,793; Algonquin (60102) 2,223; Huntley (60142) 2,196; Cary (60013) 2,113; Johnsburg and McHenry (60051) 1,984; Harvard (60033) 1,616; Marengo (60152) 1,222; Crystal Lake, Bull Valley and Prairie Grove (60012) 1,055; Wonder Lake (60097) 953; Spring Grove (60081) 739; Island Lake (60042) 419; Fox River Grove (60021) 380; Richmond (60071) 333; Hebron (60034) 180; Barrington (60010) 161; Union (60180) 133; and Ringwood and Wonder Lake (60072) 64.

Emily Coleman

Emily K. Coleman

Originally from the northwest suburbs, Emily K. Coleman is the editor for the Northwest Herald. She spent about seven years prior to that with Shaw Media, first covering the town of Dixon for Sauk Valley Media and then various communities within McHenry County from 2012 to 2016.