LOS ANGELES – A technical problem has caused a lag in California’s tally of coronavirus test results, casting doubt on the accuracy of recent data showing improvements in the infection rate and number of positive cases, and hindering efforts to track the spread, the state’s top health official said Tuesday.
Health and Human Services Secretary Dr. Mark Ghaly said in recent days that California has not been receiving a full count of tests conducted, or positive results, through electronic lab reports because of the unresolved issue, which he did not describe in detail. The state's data page now carries a disclaimer saying the numbers “represent an underreporting of actual positive cases" per day.
The latest daily tally posted Tuesday showed 4,526 new confirmed positives, the lowest total in more than six weeks and a precipitous drop from the record nearly 13,000 reported two weeks ago. County health officials have posted notices on their sites advising of the lag and that a drop in cases might not paint a full picture.
Wendy Hetherington, Riverside County's chief of epidemiology and program evaluation, said she believes hundreds of cases a day haven't been reported in her county since late last week. The undercount impedes the ability to find newly infected individuals and quickly contact those who have been in close contact with them so they can quarantine to avoid spreading the disease.
“We're delaying case investigations. We're delaying follow up,” she said, adding: “We can't tell how well we're doing until this issue is resolved."
Even with the under-reporting of cases, California has recorded more positive tests than any other state, about 520,000.
On Monday, Gov. Gavin Newsom gave his most optimistic report on the state's virus efforts since a second surge of cases in early June. He noted daily cases had dropped by an average of 2,200 in the last week and the infection rate of 6.1% was significantly lower than the nearly 8% recorded last month.
Ghaly acknowledged the rate Newsom highlighted was based on incomplete data and that missing data is being inputted manually. He stressed that looking at one- and two-week trends can help account for missing data from individual days.