LOS ANGELES – A large part of California’s multibillion-dollar porn industry ground to a halt yesterday after two actors tested positive for the virus that causes AIDS.Producers agreed to shut down sets, and at least 49 men and women were under voluntary quarantine because they had sex with the HIV-positive performers or their sex partners, said Sharon Mitchell of the nonprofit Adult Industry Medical Healthcare Foundation.

Actor Darren James was the first to test positive, Mitchell said, and one of 14 women he had on-screen sex with also tested HIV-positive.

Those 14 women had sex with 35 more partners, she said. All face voluntary 60-day quarantines. It was unclear how many people had sex with the infected actress, and how many more partners they may have had before learning of the outbreak.

“It’s very scary,” said Mary Carey, an adult movie star who ran for governor of California last fall. “This is kind of a wakeup call for everybody.”

She said she was canceling a lesbian porn shoot as a precaution even though she did not consider it risky.

A list of quarantined performers was placed on AIM’s Web site. The group screens about 1,200 adult movie performers a month for HIV and other sexually transmitted diseases.