California Undercounts COVID-19

Health officials in multiple California counties say the electronic system used by most local health departments statewide to report data on infectious diseases is currently experiencing “serious” technical issues, resulting in coronavirus cases being significantly undercounted.

The California Department of Public Health confirmed the undercounting in a Tuesday morning update to its data dashboard, after individual counties including in the Sacramento area and Southern California reported earlier in the week that they’d been made aware of the problem.

“Due to issues with the state’s electronic laboratory reporting system, these data represent an underreporting of actual positive cases in one single-day,” the note attached to the CDPH graph on daily lab-confirmed case increases reads.

The glitch comes at a critical moment for California. Faced with a surge of new COVID-19 cases statewide in June and July, Gov. Gavin Newsom last month rolled back some of the state’s earlier business reopening, and also began requiring people to wear masks in public places. Lacking up-to-date data on new cases, however, it may be harder to get a precise snapshot of how well those orders working.

Monday’s statewide data update saw just 5,739 new cases reported and Tuesday’s was even lower at just over 4,500 new cases. Those numbers would represent the two lowest single-day increases since July 5, as well as a relatively abrupt turnaround for numbers that had been spiking steadily since mid-June. California has surpassed 519,000 total lab-confirmed cases, even with the undercount. The state also reported 113 new fatalities Tuesday, bringing the state’s all-time COVID-19 death toll to 9,501.

The state did not say how many days have been affected by this issue nor did it estimate the scale of the undercounting. But individual county health officials have suggested the underreporting has noticeably affected the accuracy of their own available data in recent days.

The electronic system in question is called CalREDIE, and it is used by nearly all of California’s local health offices to track disease data and transmit it between those local offices, laboratories, health providers and the state, according to the CDPH website.

“We’ve discovered some discrepancies,” state Health and Human Services Secretary Dr. Mark Ghaly said of the data problems during a Tuesday COVID-19 update, streamed as a Zoom teleconference. “We’re working hard and immediately to reach out to the labs that we work with to get accurate information ... so we can feed that to our local county partners, that we can validate and make sure our numbers are accurate.”

Ghaly attributed the glitches to the high volume of COVID-19 case data “testing the capacity” of the state’s data collection system. He said he didn’t know when the problem would be fixed, but that in the meantime the state is working with individual labs to enter accurate data manually.