Can Charlie Sheen pass on HIV to his partners?

Charlie Sheen's HIV announcement has brought him a lot of attention, but it's also brought a lot of attention to the virus.

Sheen says it's impossible to spread the virus to his partners because it's undetectable in his blood.

AIDS Project Los Angeles Director of Client Services Jeff Bailey says as long as the HIV is below a certain level and the infected person is taking his or her medication, there's very little risk of spreading it.

"There are some research studies that have shown zero transmissions. But the general rule is that it's about 96% unlikely that a person is going to transmit HIV. And that's why it's important that someone with HIV get on medications that's right for them," said Bailey.

Sheen's doctor told Dr. Oz that he put Sheen's ex-girlfriend on a preventative drug so she would face less risk.

"We called in other doctors and they felt the risk of transmission if she took the prophylaxis and he had undetectable level was miniscule. We can't say it's zero. And so basically I think my advice to her was, 'Don't do it, but the risk is miniscule.' And she elected to then go forward because she felt so close and wanted that level of intimacy," said Dr. Robert Huizenga.

Bailey says about 60,000 people in L.A. have HIV and only about 50% are getting treated. They hope Sheen's announcement pushes people to get tested and treated.