Effective November 15, 2021, WCCHD made the transition to utilizing the CDC Data Tracker for determining the Gating Phase in Williamson County. The Phases are used to inform the public of the COVID-19 community transmission risk.
The case data that CDC Data Tracker uses is imported from the WCCHD dashboard, and based on the case and test activity will assign a level of risk of transmission. The WCCHD Phased Gating Stages document will no longer be referenced.
How CDC measures the county level of community transmission:
CDC looks at two numbers — total new cases and percent positivity — to determine the level of community transmission.
- Total new cases refers to a county’s rate of new COVID-19 infections, reported over the past 7 days, per every 100,000 residents. To calculate this number, CDC divides the total number of new infections by the total population in that county. CDC multiplies this number by 100,000.
- Percent positivity refers to the percentage of positive COVID-19 tests in a county over the past 7 days. This number is based on reports from states on a specific type of test known as a Nucleic Acid Amplification Test (NAAT). To calculate this number, CDC divides the number of positive tests by the total number of NAATs performed in that county. CDC multiplies this number by 100 to calculate the percentage of all tests that were positive.