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Mounting Rates of Drug Resistance in New HIV Infections

Patients with newly acquired HIV infections should be tested for antiretroviral-drug resistance before beginning treatment.

To date, most resistance to antiretroviral drugs has occurred among treatment-experienced HIV-infected patients with long-standing infection. However, experts fear that, as time goes on, drug-resistant strains of HIV will begin to circulate through the community and to emerge in newly infected people. Results from 2 studies support this concern.

From 1996 through 2001, San Francisco researchers tabulated drug-resistance patterns among 225 patients with newly acquired HIV infections. They found a significant increase in the prevalence of mutations that were associated with resistance to non-nucleoside reverse transcriptase inhibitors (a class of drugs in use since late 1998), from 6% of isolates in 1998-1999 to 13% of isolates in 2000-2001. The prevalence of isolates with resistance mutations against 2 drug classes also rose significantly during that period, from 1% to 13%.

Looking at resistance patterns in 377 newly infected patients from 10 U.S. cities, another group of researchers found increases in the prevalence of resistance mutations against all 3 classes of antiretroviral drugs. The prevalence of strains with resistance mutations against any 1 drug rose significantly, from 8% in 1995-1998 to 23% in 1999-2000, while the prevalence of resistance against 2 or 3 drug classes increased from 4% to 10%. Both these researchers and the San Francisco researchers found that patients with fully sensitive virus responded to treatment more promptly than did those with resistant strains.

Comment: All antimicrobial agents breed resistance, whether by misuse or by selection of naturally occurring mutants, and antiretroviral drugs are no exception. Both sets of authors suggest that, especially in areas with known high prevalences of resistance, physicians should evaluate patients with newly acquired HIV infections for drug resistance before beginning therapy.

— Abigail Zuger, MD

Published in Journal Watch General Medicine August 16, 2002

Citation(s):

Grant RM et al. Time trends in primary HIV-1 drug resistance among recently infected persons. JAMA 2002 Jul 10; 288:181-8.

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• Medline abstract (Free)

Little SJ et al. Antiretroviral-drug resistance among patients recently infected with HIV. N Engl J Med 2002 Aug 8; 347:385-94.

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