MR238 - Daily Report

last updated 2020-12-03 at 15:42

Table Descriptions

This dashboard contains two tables: one for the critical weekly metrics (Weekly Metrics) and one to monitor the daily case reports for the current week (This Week). The weekly metric table lists the metrics for the current week plus the two weeks prior. Data for the current week are provisional and will be updated as daily reports are issued by Warren County Health Department (WCHD). As the week progresses you may see increases or decreases in the positivity rate but all other metrics either increase or do not change.

MR238 Metrics

The district monitors four key metrics to gauge the presence and spread of COVID-19 in the community:

  1. the number of cases per 100k people per week
  2. test positivity rate per week
  3. week-to-week increases in new cases
  4. number of youth cases

These metrics are based on recommendations by the Illinois Department of Health (IDPH) as seen on their county and schools site. The targets themselves are derived from the IDPH document Adaptive Pause and Metrics: Interim School Guidance for Local Health Departments and adapted to local conditions.

The IDPH categorizes community spread of the virus as minimal, moderate, or substantial. They recognize that local conditions may necessitate remote learning and adaptive pause measures in the presence of minimal and moderate community spread and the district has determined that such caution is merited.

Number of New Cases and Cases per 100,000

The IDPH uses cases per 100,000 people to monitor case counts in different sized populations. It’s calculated as actual Cases / population x 100,000. If 50 to 100 cases per 100,000 people are reported in a single week, then this is a sign of moderate community spread. Values of 100 or more are signs of substantial spread. In Warren County these thresholds are crossed at 9 cases (53 per 100,000) and 17 cases (100 per 100,000). On both tables, new case counts are reported in cases per 100,000 and actual number of cases.

The district has identified 50 cases per 100,000 as its threshold for this metric. If 9 or more cases (53 cases pre 100,000) are reported in a week, then the corresponding cell is colored red to indicate the safety threshold has been exceeded.

Test Positivity Rate

The weekly test positivity rate is calculated as number of positive tests / total number of tests. A positivity rate between 5% and 8% is a sign of moderate community spread. Rates of 8% or above indicate substantial spread.

The district has identified a positivity rate of 5% or above as its threshold for this metric. If a positivity rate of 5% or above occurs for the week, then the corresponding cell is colored red to indicate the safety threshold has been exceeded. Similarly, any single day with a positivity rate of 5% or above is colored red to indicate the potential of continued or worsening spread.

Weekly Change in New Cases

In addition to actual number of cases reported, the IDPH has warning assessments based on continued increases in new cases over a two week period. Their metrics assume more gradual week-to-week changes like you would expect in a larger population. As a result, their targets do not readily apply to Warren County. None the less, the spirit of the IDPH assessments still holds: an increase in new cases from one week to the next is noteworthy and a sign of moderate to substantial community spread in the area.

The district has determined that an increase in new cases from one week to the next, especially when combined with other warning signs, merits caution. Sustained increases in case numbers over a period of two or more weeks are especially troubling. The weekly metric table lists the number of consecutive weeks of increased case counts. An increase from one week to the next is colored yellow and increases of two or more weeks are colored red.

Youth Cases

The IDPH warning assessments for increases in youth cases, where the age of the infected is less than 20, is the same as for new cases and subject to the same problem when applied to Warren County. Youth cases are historically rare making any tracking based on week-to-week change even more problematic. Despite these difficulties, monitoring and responding to youth cases of COVID-19 is a critical metric and cannot be ignored when considering school safety.

The district has set a threshold of not more than 2 youth cases per week. Any day or week with 3 or more cases will be colored in red. Additionally, when youth cases increase from week-to-week for any number of weeks, that count will also be reported. Because sustained increases in youth cases are especially problematic for safe school operations, an increase from one week to the next is colored yellow and increases of two or more weeks are colored red.

Data Sources

All data is derived from the daily reports issued by the Warren County Health Department. Data is attributed to the date the WCHD report was issued. Exact date attribution on this report will differ from what the state reports as they attribute cases to the day they received the test from the lab and not the day the test was reported to the public. You can see a recent window of state data by looking at the IDPH Regional Methodology. In general, the totals over the entire pandemic agree but day-to-day distributions differ, typically by small amounts.