Data Notes for the Week of October 15

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:

Dane County’s 14-day average number of cases has increased.  

Cases per day ranged from 69 to 217 with an average of 133 cases per day. Last week’s average number of cases per day was 120. In this 14-day period there were 1,866 total cases.

We define a cluster of cases as two or more cases associated with the same location around the same time. A recent example of this is an office building where staff have been working in person. One of the staff went to work while they were infectious with COVID, and then two of their coworkers subsequently also tested positive the following week.

Of the 1,669 non-UW cases in this period, 150 (9%) were associated with a cluster: 45 from less public-facing workplaces, 20 from childcare facilities (7 children and 13 adults), 18 from more public-facing workplaces, 17 from congregate facilities, 17 from health care facilities, 8 from weddings, 7 from bars and restaurants, 6 from schools, 4 from gatherings, 3 from supported living services, 3 from gyms or athletic facilities, and 2 from churches. The six school cases were all staff and came from clusters in two schools where staff are working in person but no children were present.

A single case in a congregate living facility (e.g., long term care facilities, fraternities and sororities), a childcare facility, or a school initiates a facility investigation by our staff. A case “in” a facility means that the person who tested positive was in the facility while they were infectious. These types of facilities are prone to outbreaks and can contain vulnerable populations, and our case investigators work with them to ensure they are following best safety practices. The goal is to prevent a cluster of cases from occurring within the facility.

In this 14-day period, there were 12 schools (7 students and 8 staff), 9 childcare facilities (3 children and 7 adults), and 15 congregate facilities that had a single case (or multiple cases that were not linked to each other) but have so far prevented further spread from occurring.

The age group with the highest number of cases is now ages 30-39.

During this snapshot period, ages 18-22 is the only group this week that has fewer cases than last week. Every other age group has a greater number of cases this week compared to last week. This has resulted in a fairly even distribution of cases of 18 year olds through 59 year olds: 15% of cases were 18-22, 16% of cases were 23-29, 16% of cases were 30-39, 14% of cases were 40-49, and 13% of cases were 50-59. The proportion of cases ages 18-22 continues to decrease; last week, 22% of new cases were among 18-22 year olds. In our 10/1 snapshot, 45% of new cases were among 18-22 year olds.

The recommended target for grades 3-5 was not met this week.

The K-12 school metrics are detailed on our website. The Wisconsin Supreme Court issued an injunction that allows K-12 schools in Dane County to fully open for in-person instruction. We are disappointed in this decision and strongly urge all schools to continue voluntary phasing-in of classes for in-person instruction for grades 3-12. We will continue to update data weekly and advise schools on their reopening plans.

There was no statistically significant change in COVID-like syndromic cases, turning this metric back to green.

As defined by the Wisconsin Department of Health Services, these are emergency department visits for people with COVID-like symptoms, whether or not they are tested or test positive, and these can be an early warning indicator for future hospitalizations. A portion of emergency department visits will become hospitalized, so with an increasing number of emergency department visits for COVID-like symptoms, an increasing number of hospitalizations with COVID-19 could follow.

The number of patients hospitalized with COVID-19 in Dane County has been increasing, from 37 hospitalizations on 9/29 to 78 hospitalizations on 10/13.

Hospitalizations have continued to rise over the past two weeks, peaking at 78 hospitalizations on 10/13. We continue to see this upward trend in the South Central region and in all of Wisconsin. We are monitoring hospitalizations very closely because increases in hospitalizations can lead to a strained healthcare system that struggles to meet the needs of all patients. Madison-area hospitals announced last week that they may be postponing non-emergency and non-urgent procedures and surgeries as COVID-19 hospitalizations increase.