LOS ANGELES (AP) — Figures showing California has slowed the rate of coronavirus infections may be in doubt because a technical problem has delayed reporting of test results, the state's top health official said.

For days, California hasn't received full counts on the number of tests conducted nor the number that come back positive for COVID-19, Health and Human Services Secretary Dr. Mark Ghaly said Tuesday.

He blamed an unspecified technical problem affecting the state's database that provides test results to local health departments. Ghaly said it's unclear when the issue would be fixed, adding that the state is relaying information manually to county health officials.

The announcement came a day after Gov. Gavin Newsom gave his most optimistic report on the state’s virus efforts since a second surge of cases in early June. Newsom said 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.

The latest daily tally posted Tuesday on California's COVID-19 data page showed 4,526 additional confirmed positives, the lowest total in more than six weeks and a precipitous drop from the record of nearly 13,000 reported two weeks ago.

However, the page now carries a disclaimer saying the actual daily number of positive cases is being underreported.

At issue is CalREDIE, a state system that electronically receives COVID-19 test data from lab providers. The name is short for the California Reportable Disease Information Exchange.

“There’s a specific component that feeds information from labs to both the state’s system and the local public health system," Ghaly said. “That may actually be the place where data is getting stuck.”

Counties including Orange and Sacramento have noted the delays, and Placer County posted on its website that its virus cases are likely underestimated as a result.

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.

That makes it hard to find newly infected individuals and to reach out to people who've had close contact with them in order to trace and reduce the spread of the virus.

“We’re delaying case investigations. We’re delaying follow up,” she said, adding: “Until this lab issue is fixed, we can’t really say what the true picture is.”

Los Angeles County health officials said the state convened an emergency call Monday night to discuss the issue. Now, a team from the county is reaching out to more than 80 labs to obtain test results for the past nine days to determine an accurate case count, and set up a system to receive data directly in the future so contact tracing efforts aren’t delayed, the county’s health department said in a statement.

Even with the underreporting of cases, California has recorded more positive tests than any other state, about 520,000.

Ghaly said hospitalization data, which doesn’t run through the same troubled system, has seen signs of improvement. The latest count Tuesday showed 6,302 people were hospitalized, a 12% drop from the high recorded in July. Deaths have now topped 9,500.

Aside from the delays, the number of infections is generally thought to be higher than the reported cases because many people haven’t been tested, and studies suggest people can be infected without feeling sick. For most people, the virus causes mild or moderate symptoms, such as fever and cough, but for some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia, and death.