Scientists at the University of Michigan have revealed that the virus that causes AIDS can hide in the bone marrow, and come back to cause the illness when patients stop taking medicines.

Ashley Hall reports that doctors have been able to trim down the amount of HIV in the blood of patients by combining different drugs. But once the patient discontinues the medicine, the virus jumps back into action.

Kathleen Collins, an Associate Professor of Internal Medicine at the University of Michigan, and the Lead Author of a Study published in the journal, Nature Medicine said, “We found there was evidence that HIV in fact, does infect the bone marrow progenitor cells or parent cells that are the source of all of the different blood lineages in the body and moreover that HIV can take on a latent form and so we were able to detect the presence of virus ending cells even after patients had been on therapy for years”.

"I don't know how many people realize that although the drugs have reduced mortality we still have a long way to go. That is mainly because we can't stop the drugs, people have to take it for a lifetime", said Collins.

Dr. Kersten Koelsch, who is working with National Centre for HIV Epidemiology and Clinical Research at the University of New South Wales, said that this discovery will not help patients who are already infected with HIV in the near future.