Public Health Madison & Dane County

Posted on Monday, Jul. 27, 2020 at 9:21 am

As we began talking about in our data snapshots on July 6 and July 13, and explained more in our blog post and July 20 snapshot, over the past couple of weeks, our data dashboard has appeared to have a high percent positivity rate. This is because each negative test has to be processed manually by a staff person. Our staff prioritize processing positive results, and as the amount of testing has increased (to about 2,400/day), we have had a backlog of negative tests to process. Positive tests are always immediately verified and processed, and delays in processing negative tests in our data system does not affect notification of test results. The only effect this backlog has had is on our percent positivity rate and daily test counts.

Our data team has been working on a solution, and as of Friday, we are now including negative tests on the dashboard that have entered our data system but have not yet been processed by our staff. Around 17,000 negative tests were added to the dashboard using this updated methodology. Recent dates are subject to change, as some tests are determined to be out of jurisdiction when they are processed. With this additional data added, the percent positivity rate over the past 7 days is 2.1%.

We dedicate a lot of staff time and resources to maintain our data dashboard and ground data in our decision-making. To be clear, percent positivity is just one metric we monitor and was not the reason for the new orders that were issued in July. We issued orders with new restrictions effective 7/2/20 because from June 20, 2020 through June 26, 2020, 482 individuals tested positive for COVID-19, which was the highest of any seven day period. The number of cases increased by 45% in just one week which was the largest percent increase we had since the end of March. When the order for face coverings was issued on July 7, we had just again experienced the highest ever number of cases in 7 days: 780 cases from 6/27 to 7/3. Additionally, our lab timeliness and contact tracing metric turned red, and our community spread metric was red.