Drugs meant to wipe out HIV may have to be used for significantly longer than they have been before all detectable signs of the virus are gone, according to a computer model described in the May 8 edition of Nature. The studies are disappointing news for HIV-positive patients who dared hope for a cure last year when researchers announced that a triple-drug therapy could obliterate all traces of the virus in the blood.
The two new studies indicate that the virus remains hidden in cells of the immune system in patients who have been treated for more than two years. Mathematical models developed at the Aaron Diamond AIDS Research Center indicate that treatment must continue 2.3 to 3.1 years to eliminate the virus from those cells. Even then, researchers fear, it might require only one infected cell to start the disease cycle over again.