County health departments behind in processing negative tests, affecting daily COVID-19 data

MADISON – Some county health departments are behind in processing and reporting thousands of negative coronavirus tests, which could distort some daily virus data reported by the state.    

Local health officials are experiencing backlogs in processing negative tests, which pushed Dane County this week not to calculate its percentage of positive tests — a data point the public uses to determine how intense infection is in an area.   

While positive test results are being processed and their number reported quickly, negative test results are taking days in some cases to be analyzed before they are reported to the state. 

Health Services Secretary Andrea Palm said the public should instead, for now, rely on a seven-day average of the percentage of positive tests to find the most accurate picture of the virus spread in Wisconsin.

“On a day-to-day basis, it certainly impacts those numbers,” she said Thursday about the backlogs in a briefing with reporters. 

State Health Officer Stephanie Smiley said Tuesday “many local health departments” are experiencing delays, including Dane County, where health officials are about 10 days behind in processing negative results, due to “thousands upon thousands” of new tests each day.  

“Because of the numbers that we’re seeing every day — the thousands of results that are reported to us — we are seeing backlogs,” Smiley said. 

Palm said overall, delays are generally between one and three days behind. 

Brittany Grogan, a data analyst for Public Health Madison and Dane County, said the agency has hired more people in the last couple of weeks to catch up. 

She said test results are still being distributed quickly but an influx of people being tested, particularly at the community testing site at the Alliant Energy Center, has resulted in thousands of tests that must be fully processed — which includes manually verifying a person who has been tested more than once isn’t double-counted in the overall testing data.

She said the agency is considering categorizing its data as preliminary and confirmed, or posting the number of negative tests that still must be processed, in order to provide the most accurate picture of the virus spread in the county.

Another piece of data the public relies on to figure out whether the virus is spreading or slowing also was missing this week.

The number of infected patients hospitalized has not been reported publicly since Tuesday as the state responds to new guidance from the U.S. Department of Health and Human Services on how and where to report hospital capacity data. 

“The reporting changes were requested and occurred in a very short time frame — less than a week,” Mark Grapentine, spokesman for the Wisconsin Hospital Association, said in an email.

All of the state’s hospitals had been reporting data to the state Department of Health Services in order to track capacity but the federal health agency now is requesting additional and different data that hospitals and health systems are still developing processes to collect, Grapentine said. 

He said he anticipated the WHA dashboard will show updated numbers in a day or two.

Wisconsin health officials announced 1,052 new COVID-19 cases Thursday, the second time this week the state has surpassed a thousand cases in a single day. 

The surge in infections, which has caused the state to hit three single-day records of new cases reported in just one week, remains largely driven by two trends: an increase in people making outings to parties, bars and other social events, and an increase in cases among young people. 

One-third of cases reported in the last month have been among people in their 20s, Palm told reporters. 

Health officials also announced 13 more deaths related to the virus Thursday, bringing the state’s total to 878. More deaths have been reported in the past seven days than in previous weeks in July, DHS data show.

Contact Molly Beck at molly.beck@jrn.com. Follow her on Twitter at @MollyBeck.