SACRAMENTO, Calif. — California began adding additional coronavirus cases to its public record Tuesday, a week after state officials acknowledged a data problem in late July had caused nearly 300,000 records not to appear in its health system.

The state reported 12,500 confirmed cases, up sharply from its previous 14-day average. But it was not clear on what dates the confirmed cases were found.

The data glitch has been embarrassing for the state of 40 million people, which relies on timely statistics to determine whether schools and businesses can reopen.

Statewide, nearly 10,500 people have died from the coronavirus and there are more than 570,000 confirmed cases.