Huge spike in positive COVID-19 cases linked to testing backlog
SPRINGFIELD — The Illinois Department of Public health reported by far its single highest number of COVID-19 test results Friday. But that’s because a multi-day backlog of reporting was cleared and the data is just now being reported, not because of an exponential rise in the number of new cases.
Officials say they also are adjusting the trailing average to reflect the most accurate number for decision makers.
IDPH reported 5,368 new positive tests, the most ever reported in one day. The highest amount of positive tests reported in one day before that was 4,014 on May 12, and that was an outlier. The second largest amount reported in one day before Friday was 3,239 reported May 14.
The number of total tests reported Friday was exponentially higher than any other day at more than 150,000. The highest before Friday was a total test count of 56,766 on Aug. 22.
IDPH Assistant Director Dr. Amaal Tokars reported Wednesday there was a backlog.
“The Illinois Department of Public Health is reporting today approximately 32,751 COVID tests,” Tokars said then. “While all results have been reported out to those tested, we are experiencing minor tech issues in the data processing system, the system we use to report out tests publicly, and that is why this number is somewhat lower than the 40,000 and 50,000 tests we’ve been reporting previously.”
The number of total positive tests divided by the number of total tests administered is the positivity rate. Positivity rates have been used by Gov. J.B. Pritzker’s administration to implement COVID-19 mitigations in various regions of the state, impacting economies.
During a background call with IDPH staff, they said the trailing averages is what decision makers use, and they will be updating them retroactively to make sure the trailing average reflects the reality, and not the delay in testing. They said they’re confident it won’t affect the true picture of the positivity rate.
“Using a 7-day rolling average for this metric helps account for any variation in day-to-day data collection, such as a data processing slowdown, and provides the public and decision makers with a consistent picture of trends over time,” the department said in a statement.
IDPH officials said the slowdown doesn’t impact when a person gets notified of their test results, but does impact how they are publicly reported out.
The test results aggregate reporting is done internally.
The number of COVID-19 related deaths was not affected. Friday’s report included an additional 29 deaths. There were 1,621 of nearly 35,000 total hospital beds statewide taken by a COVID-19-symptom patient.