Two HIV positive patients have no signs of the virus in their blood after undergoing bone marrow transplants, their doctors said Wednesday, Reuters reported.

Dr. Timothy Henrich, an associate physician at Brigham and Women's Hospital in Boston, made the announcement at the International AIDS Society conference in Kuala Lumpur that the men are no longer taking AIDS drugs. Currently, the first patient has been off treatments for 15 weeks and the other has been off for seven weeks

"I don't want to use the 'cure' word," said Dr. Timothy Henrich, a Brigham infectious diseases associate physician who is leading the study. "If they remain virus-free in a year, or even two years, after [stopping] therapy, then we can make a statement that the chances of the virus returning are very low."

Henrich and coauthor Dr. Daniel Kuritzkes first made the announcement last summer that HIV, the virus that causes AIDS, was easily detected in the patients' blood prior to their bone marrow transplants but could not be found eight months after the transplant.

However, experts are not calling this the cure for HIV for most patients.  Dr. Jay Levy, an HIV researcher at the University of California, San Francisco, said the Boston results are encouraging but the patients need to be monitored much longer to know whether the virus has been truly knocked out.

"The next step is to confirm this in larger numbers," said Dr. Sharon Lewin, an infectious disease professor at Monash University in Melbourne, Australia, told MedPage Today.

Lewin, who did not treat the Boston patients, said she did not believe that the stem cell treatment would become widespread because of the risk and money involved. However, patients who undertake the treatment are "absolutely instrumental in moving the science forward."

There are current 33.4 million people are living with HIV or AIDS in the United States, according U.S. government statistics. In the U.S. alone, 1.7 million people have been infected with HIV by the end of 2008, the most recent year where statistics are available. Every 9.5 minutes, someone is infected with HIV. Currently, one out of five people living with HIV are unaware that they are infected.