Data Notes for the Week of August 3

Today we released this week’s data snapshot. If you’re new to the data snapshot, we publish a weekly summary of the status for each of our metrics (you can find past issues on our data and metrics page). We have a few notes for this week’s issue:

Our average number of cases per day continues to decrease, but has remained significantly above the red threshold.

The number of cases per day metric was red in the last data snapshot, and it remained red during this 14-day period. Cases per day ranged from 18 to 76, with an average of 50 cases per day, down from 63 in the last snapshot. While this is an improvement, we remain significantly above the threshold for this measure to become yellow (20 cases per day).

From July 18 through July 31, 705 people tested positive for COVID-19 in Dane County. As of this morning, 582 have had complete interviews. Here’s what we know about these cases:

• Of all 705 cases, 435 (62%) were tested at community testing sites (423 at the Alliant Energy Center).
• Of all 705 cases, 183 (26%) were young adults between the ages of 18-25.
• Of 582 people who have been fully interviewed so far, 201 (35%) reported attending a gathering or party with people outside of their household.
• Of 582 people fully interviewed so far, 329 (57%) identified the likely source of infection as close contact with another lab-confirmed COVID-19 case.
• Of 582 people fully interviewed so far, 79 (14%) were associated with a cluster: 21 from workplaces, 18 from childcare facilities, 14 from congregate facilities, 7 from bars and restaurants, 7 from supported living services for adults, 7 from youth camps, 3 from college-aged housing (including sororities, fraternities, near-campus apartments), and 2 from sports teams.

The lab timeliness and contact tracing metric continues to improve.

Lab timeliness (how quickly labs are reported to us) and contact tracing (how quickly we can reach out to cases) are combined into one metric because lab timeliness directly affects contact tracing. This metric has continued to improve: 64% of cases were contacted within 48 hours of being tested in this 14-day period, compared to 52% from our last snapshot. This metric will turn yellow when 70% of cases are contacted within 48 hours of being tested.

This metric is also highly dependent on how quickly individual labs can process tests and report the results. 70% of positive tests were reported within 24 hours, and 72% of cases were interviewed within 24 hours of their test result.

The median age of cases has increased from 7/6 to 7/29, even as the fastest growing age range of cases during that timeframe was ages 10-19.

The median age of cases has increased from 22.5 in the 7/6 snapshot to 29 in today’s snapshot. As of the 7/6 snapshot, the percentage of cases aged 30+ was 30%, compared to today’s snapshot, where the percentage of cases aged 30+ was 49%.

The median age of cases has been increasing despite the 10-19 age range seeing the highest rate of growth. On 7/6, the percentage of cases aged 10-19 was 8% (and 57% of the 10-19 year old cases were ages 18 or 19); as of today, 19% of cases were 10-19 (and 41% of the 10-19 year old cases were ages 18 or 19).

We are continuing to see a high level of community spread in Dane County.

The community spread metric remains red: 39% of people with COVID-19 did not know where they could have been exposed, compared to 36% from last week’s snapshot. A high percent of cases with no known route of disease transmission means there is likely a large number of individuals unknowingly spreading the virus in the community, which makes isolation and contact tracing much more difficult.