Vivid Entertainment Group, the nation's top adult movie maker, has resumed new movie production nearly a month after a performer's positive test for the AIDS virus prompted a self-imposed moratorium that shut down much of the multibillion-dollar U.S. porn video industry.

At least five performers tested positive for the virus that causes AIDS since actor Darren James apparently acquired it in March while shooting a movie in Brazil, health officials said. One of those cases, however, involved a transsexual actor whose case was unrelated to the others.

About 50 people who performed with either James or those he worked with were put on a voluntary quarantine list that effectively prevented them from doing sex scenes until they had passed two monthly HIV tests. Twenty have been cleared to work.

"It's over. Business is looking up," said Tim Connelly, publisher of the industry online magazine AVN.

After a weekend shoot to complete a movie held up by the moratorium, a Vivid crew went to work Monday at a home in the Sun Valley area on a new production. As hand-held cameras roamed, two pairs of performers went through their paces on a patio swing and near a backyard pool.

The moratorium affected an estimated $4 billion- to $10 billion-a-year business -- based mainly in the San Fernando Valley -- that churns out 4,000 new movies a year.

Connelly estimated that about 85 percent of production companies heeded the work stoppage.

"One of the companies I know is going to shoot for the next three weeks nonstop. ... Everybody's really happy," he said.

Los Angeles County health officials (search), however, argued that the overall risk to performers in the unregulated business remains unacceptable.

There should be mandatory use of condoms for adult film shoots, county Health Officer Jonathan Fielding said.

"The moratorium is ending without the introduction of the safest protection measures we have," he said. "I am distressed by the fact that these workers are going back into circumstances that put them at ... unnecessary risk of contracting life-threatening illnesses."

While many in the industry support voluntary condom use, most oppose making it a law on grounds that it would drive the business underground.

The industry relies on monthly HIV tests (search) administered by the nonprofit Adult Industry Medical Healthcare Foundation (search).

Performers were initially told they would have to wait to resume work until at least June.

Those working Monday said they were aware of the HIV risk but felt relatively safe.

"Today's my first day going back to work from the whole HIV thing. But it really doesn't affect me that much because I do condom-only (scenes) and I pick who I work with," said Tawny Roberts, a 24-year-old Vivid star who came to adult films three years ago.

"Obviously, it's more enjoyable without the condom, but I think it's safer and that's what I choose to do," she said.

Vivid makes more than 50 adult feature films each year and also releases dozens of compilations. The company is condom-only, as compared to smaller "gonzo" producers who shoot unprotected scenes and more extreme sex. Gonzo producers say consumers demand their product because condoms spoil the fantasy.

Co-star Brooke, 20, said the HIV scare prompted her to give up unprotected sex scenes.

"A thousand dollars is not worth my health," she said of the going rate for a sex scene.

"I know that a lot of people don't want to see condoms, but I would like to see tomorrow," she said.

A new performer, 37-year-old Tommy Gunn, said he would continue to do both kinds of work.

"It was a question of when it was going to happen, I guess," he said of the HIV scare. "It's like skydiving, you assume a certain risk."

"You just do it, and that's that, and I'm comfortable with it," he said. "It's just an issue of it's your time, it's your time, I guess."