Timothy R. Brown attends a press conference to announce the formation of the Timothy Ray Brown Foundation on July 24, 2012, in Washington, DC.

Brown, known as the "Berlin patient," says doctors have told him he's "cured of AIDS and will remain cured." His case is rare:

Brown had a blood stem cell transplant in 2007 to treat leukemia and his blood donor possessed a rare genetic mutation that provides natural resistance to HIV. Doctors declared him "cured" soon after.

Brown addressed the media in the U.S. for the first time Tuesday during the XIX International AIDS Conference in Washington, D.C.

Researchers in California recently found traces of HIV in Brown's tissues, but he said remnants of the virus still in his body are dead and can't replicate.

Timothy Ray Brown attends "Together To End AIDS: An Evening To Benefit amfAR and GBCHealth" at John F. Kennedy Center for the Performing Arts on July 21, 2012, in Washington, DC.

Last June, Brown told CBS News, "I quit taking my HIV medication on the day that I got the transplant and haven't had to take any since."

About one percent of Caucasians are thought to have the genetic mutation that makes a person immune to HIV.