Data Notes for the Week November 19

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 (data from November 3—November 16):

Over the past two weeks, more than 1 person out of every 100 people in Dane County tested positive.

For the sixth straight week, Dane County’s 14-day average number of cases increased. It is currently 436 cases per day, up from 364 in the last snapshot. One month ago, in the October 15 snapshot, we reported a 14-day average of 133 cases per day.

The number of cases per day ranged from 176 to 700. In this 14-day period there were 6,141 total cases.

Clusters continue to grow in assisted living and skilled nursing facilities.

This is particularly worrisome given the severe outcomes this population is experiencing, here and nationally.

We are not capturing every case associated with a cluster.

At least 14% of cases were associated with a cluster and/or a facility investigation. When assessing clusters, keep in mind that the data we share is likely an undercount of the true number of clusters in the community.

• Clusters are defined as two or more cases associated with the same location, group, or event around the same time. In a facility with a cluster, staff may be easily identified as part of that cluster, but clients or customers who are part of that cluster are less likely to be identified. This is because they could have many potential sources of exposure (or many places they went while they were infectious). We don’t always have details on the specific places they went or the specific dates and times they were there.
• Additionally, our staff have not been able to contact trace all cases due to the very high burden of cases in Dane County, which means that we may be missing many clusters or people connected to clusters due to lack of interview data.
• We recommend using cluster data to get a general sense of where clusters are being identified. Assume that actual numbers of clusters are an undercount, and do not interpret these numbers as the total number of clusters in Dane County. When learning about how COVID-19 spreads in different settings, we recommend looking at national data in addition to local data. For example, CDC has recently published national examples of clusters we see here related to workplaces, hockey, and weddings.

We continue to see clusters associated with workplaces, health care facilities, childcare facilities, schools, sports teams, bars and restaurants, and churches. The Dane County Jail is experiencing a new cluster which is represented in the Correctional Facility category. See page 2 of the snapshot for more details on clusters.

We want to remind people that close contact is what spreads COVID-19. Using virtual options and avoiding close contact, crowds, and confined spaces without ventilation can lower your risk for getting sick.

The percent positivity metric increased again and is at 8.3%, its highest level ever.

Percent positivity last snapshot was 7.4%. Dane County has steadily increased testing each week so we expected more cases, but the increase in cases far outpaced the increase in testing. This means we know the increase in cases isn't solely from more testing. An increase in percent positivity can indicate more widespread infection, so more testing is needed to capture all cases.

Latinx and Black Dane County residents are disproportionately represented among people testing positive and people hospitalized for COVID.

• During this two-week period, members of the Latinx population represented 18% of total cases and 16% of total hospitalizations but are only 6% of the Dane County population.
• Black, non-Hispanic people represented 8% of total cases and 13% of total hospitalizations but are only 6% of the Dane County population.

The median number of days between symptom onset and test date for people who have tested positive has increased.

Since August, the median number of days between symptom onset and test date has been 1 day. This week that median shifted to 2 days. This means that people are waiting longer to get tested once they start having symptoms, or they are experiencing barriers in accessing testing when they need it.

The number of patients hospitalized with COVID-19 in Dane County is higher than it has been any time during the pandemic.

In the past two weeks, the number of patients hospitalized with COVID-19 in Dane County has increased, peaking at 179 hospitalizations on November 18. The South Central Region has a growing trajectory for COVID patients hospitalized and COVID patients in the ICU. Increases in hospitalizations are concerning because strained health care systems may struggle to meet the needs of all patients—not just those with COVID.

2% of cases in this 14-day period were hospitalized. The risk of being hospitalized increases with age: 13% of cases age 70+ were hospitalized while 1.4% of cases age 23-69 were hospitalized.

Within this 14-day period, twelve hospitals in our region reported at least one day of critical staffing shortage. One of these hospitals was within Dane County.

Looking Ahead

• Next week’s snapshot will be released on Wednesday.
• Because our contact tracers are responding to so many cases so rapidly, not every question is captured in each case interview. This has possible implications for how we report risk characteristics on page 2 of the snapshot. We are currently assessing our methodology and future snapshots will outline the details of any change in methodology.