MADISON (WKOW) – Public Health Madison and Dane County on Friday tackled their fight to process a backlog of negative COVID-19 test results, skewing their reported infection rates.
According to DHS secretary Andrea Palm, this was a problem that affected many municipalities throughout the state.
“As they prioritized those positive cases, the negative cases are being delayed by a day or two or even three as they are making sure they are focusing on stopping the spread,” he said.
In a massive update, the online public health dashboard keeps aggregated about 17,000 negative test results that adjust last week’s positive rate to 2.1 percent.
The positive percentage rate measures how many COVID-19 tests have yielded positive results. Expressing the returns as a percentage helps to consider whether an increase in new cases is due to more evidence or more spread.
Public health uses the positive percentage rate as one of its metrics in the Forward Dane reopening plan that governs how and when certain measures of social distancing, including many imposed on companies, can be relaxed or eliminated.
Recognizing the problem, public health suspended the calculation of its metrics regarding the percentage of positive results and the total tests carried out this week.
“In the past two weeks, our data panel appears to have a high percentage of positivity,” public health said in a Facebook post. “This is because each negative test must be manually processed by a staff member. Our staff prioritizes the processing of positive results and, as the number of tests increases, we have had to accumulate a backlog of negative tests to process.” .
In the past few weeks, it had not been uncommon for the Dane County positive percentage rate for the most recent day to start in double digits and then slowly adjust as time passed and the county processed more negative tests.
The numbers on the data panel gave the impression that the county continually saw further spread of COVID-19.
The most recent data shown on Friday morning was for July 18. The numbers showed a positive daily rate of 6.1 percent and a weekly average of 13.4 percent. As of Friday afternoon, after adding the new negatives, the July 18 daily rate dropped to 2.1 percent and the weekly rate at that point was less than four percent.
Dane County, according to the now updated dashboard, saw a sharp increase in COVID-19 cases beginning in late June. However, that rate began to decline as the weeks progressed.
