State data errors cause massive Covid-19 case undercount

Santa Clara, San Benito counties affected by state reporting problems

222

Errors in the state’s Covid-19 data reporting system have led to vast undercounts of both positive and negative results in counties throughout California.

A message on Santa Clara County’s “Novel Coronavirus” web page stated the local number of Covid-19 cases and related data “has been underreported for the last few weeks.”

“The state is in the process of providing the backlogged data to counties statewide, and we have been expecting a large number of cases to be reported today and possibly over the next few days,” the Aug. 10 message from Santa Clara County stated. 

Based on data received from the state over the weekend, Santa Clara County on Aug. 10 reported 751 new Covid-19 cases. This number includes a combination of positive tests from as far back as July 8, though most are from last week.

Gilroy reported 189 new Covid-19 cases between Aug. 3-10, while Morgan Hill had 63 new cases over the same period. However, as county health officials pointed out, those numbers are incomplete since mid-July due to errors in the state’s system.

The issues with the state’s Covid-19 data system have caused hundreds of thousands of health records to go unprocessed, impacting the validity of the California Reportable Disease Information Exchange (CalREDIE), according to San Benito County officials. All counties in California rely on CalREDIE when updating local online data dashboards.

State officials, as of Aug. 10, have reported that the software problem has been corrected and all backlogged cases should be entered into the system by the end of this week.

“We are currently analyzing the newly-received data, any remaining gaps, and what it tells us about the course of the pandemic in our county,” Santa Clara County health officials stated.

“While we are not sure the effect this will have on San Benito County as total number of reported cases are still unknown, it’s clear that on a larger scale, somewhere between 250,000 and 300,000 health records, which included tests for the novel coronavirus, went backlogged because of the technological problem,” stated San Benito County Interim Health Officer Dr. David Ghilarducci. 

California State Health and Human Services Agency Secretary Dr. Mark Ghaly said Aug. 7, “No counties have been taken off or added to the monitoring list since last Friday, because the state paused changes to the list in order to make sure its data was accurate before moving forward.”

To address the data system error, the state is putting into place new protocols and notifications when any changes are made to the CalREDIE system, reads a press release from San Benito County. State officials made upgrades to the servers to ensure they have extra capacity, and there is now a redundant system to validate data and reports. Oversight and monitoring has been strengthened so case data is complete, timely and validated. Finally, the governor has directed a full investigation of what happened.

Ghaly apologized for the errors, and said the state’s “antiquated” data records system has failed the people and made containing this “uncontainable” disease even harder. 

“[The people of California] deserve better, the governor demands better of us, and we are committed to doing better,” he said.