1. Home>
2. Specialties>
3. General Medicine>
4. Summary and Comment

Drug-Resistant HIV May Cause New Infections

As drug-resistant strains of HIV become more prevalent, they inevitably will pass from one person to another. Case reports already have documented this disturbing phenomenon, and two studies now attempt to estimate its frequency.

In one study, viral isolates from 80 newly HIV-infected subjects referred to a research team between 1995 and 1999 were examined retrospectively for drug-resistance mutations. Most subjects were gay men from the New York City area who had experienced primary infection a mean of 1.7 months earlier. Mutations commonly associated with drug resistance were found in 13 of 80 patients (16 percent), and 3 had mutations that conferred resistance to more than one class of drugs. Although no clear chronological trend emerged, 5 of the 7 samples obtained in 1999 had mutations that would be expected to reduce drug susceptibility.

A second retrospective study analyzed viral isolates from 141 newly infected individuals, most of whom (85 percent) were infected between 1996 and 1998. Drug resistance was determined for isolates by direct, in vitro analysis of each drug's ability to inhibit viral replication. Moderate reductions in susceptibility to at least one drug were found in 36 of 141 samples (26 percent), while 3 (2 percent) had high-level drug resistance.

Comment: Since the definition of drug resistance in HIV infection and the best way to determine it are far from certain, these studies present many more questions than answers for clinicians. But the bottom line, as an editorialist notes, is that resistant virus is afoot in the community, and efforts to prevent transmission must continue.

— A Zuger

Published in Journal Watch General Medicine October 5, 1999

Citation(s):

Boden D et al. HIV-1 drug resistance in newly infected individuals. JAMA 1999 Sep 22 282 1135-1141.

• Original article (Subscription may be required)
• Medline abstract (Free)

Little SJ et al. Reduced antiretroviral drug susceptibility among patients with primary HIV infection. JAMA 1999 Sep 22 282 1142-1149.

• Original article (Subscription may be required)
• Medline abstract (Free)

Pomerantz RJ. Primary HIV-1 resistance. JAMA 1999 Sep 22 282 1177-1179.

• Original article (Subscription may be required)
• Medline abstract (Free)