Drug-resistant strains of the virus which is said to cause AIDS are rising, according to two new studies published in the American Medical Association's journal.
The studies involved mostly gay white men, but resistance may be more acute in other groups like drug users and their sex partners, according to researchers cited by the Associated Press.
The AP says some 40,000 new HIV infections occur each year in the United States. Powerful drug cocktails have subdued it to undetectable levels in many patients, the AP continues, but studies say it persists or comes thundering back 10-50 percent.
Moreover, the wire service says, the complicated drug program is difficult to sustain, with many patients who miss doses or quit the medication entirely developing drug-resistant infections now passed on to others.
And HIV is still so comparatively new that scientists do not agree about how to define resistance, the AP says, with no one really knowing how definitions would turn into patient care, though one researcher tells the AP giving high doses of a certain drug could be enough to overwhelm a virus's resistance.
Another says that when a patient takes a drug cocktail faithfully and it doesn't work, it's time to consider tests for how the combination could be reformulated.
