From the McHenry County Health Department:
MCDH TO USE IDPH POSITIVITY RATE
WOODSTOCK — The McHenry County Department of Health (MCDH) is aligning its positivity rate with the Illinois Department of Public Health (IDPH) after identifying a discrepancy in the positivity rate due to different methodologies between the two health authorities.
Preliminary research into the discrepancies in McHenry County’s positivity rate can be attributed to several differences in MCDH’s and IDPH’S methodology for calculating positivity.
MCDH calculates positivity using a method previously used by IDPH.
The most notable difference is that MCDH makes every effort to count each person tested only once, so that multiple test results for a single individual do not inflate positivity. [Emphasis added.]
Alternatively, the state counts every positive and negative test even if they come from the same person.
This is considered to have a minor impact on positivity.
After careful consideration, MCDH has decided to present the positivity statistics provided by the State.
Although MCDH has complete confidence in the methodology it has been using, the health department has decided to utilize the same data as IDPH to stay consistent with how the State is interpreting and measuring positivity.
Test positivity is one of eight metrics used by the State to evaluate warning signs of increased COVID-19 spread in a community.
MCDH is seeing cases rise dramatically and recently saw the highest single day lab confirmed case increase since the pandemic started.
MCDH is mandated to do case investigations and contact tracing to isolate and quarantine individuals to slow the spread of disease.
MCDH is currently seeing a high level of noncompliance with its investigations, hampering efforts to slow the spread of COVID-19 in McHenry County.
“It’s extremely important for everyone to participate in case investigations and contact tracing so the proper public health authority can advise its residents on ways to mitigate the spread of the virus in their homes and to those closest to them,” said Public Health Administrator Melissa Adamson.
“If you receive a call from 312-777-1999 and/or COVID Contact, please answer the call and help us slow the spread of COVID-19 in McHenry County.”
Get additional information about school guidance, school metrics and other resources by visiting https://bit.ly/MCDHSchools.