Editorials

WASHINGTON — The share of HIV infections that are drug-resistant will jump to 42 percent in San Francisco by 2005, according to a team of researchers. 

Estimating the current rate of drug resistance at 28.5 percent, the group used a mathematical formula to calculate its likely increase over the next few years. 

HIV, human immunodeficiency virus, is the agent that causes AIDS. 

The work of the team, led by Dr. Sally M. Blower of the University of California at Los Angeles, is published in Friday’s issue of the journal Nature Medicine. 

The scientists calculated the increase in drug-resistant HIV since 1997 and used that to extend their forecast into the future. 

The primary reason for the increase, they said, is the development of drug resistance in the virus during treatment. The transmission of drug-resistant strains remains low, they said, estimating that it will account for just 16 percent of new HIV cases by 2005. 

“The good news is that transmission of drug-resistant HIV will not become a major public health problem,” Blower said in a statement. “The bad news is that the prevalence of drug-resistant HIV is already high and will continue to substantially increase.” 

A complex combination of drugs is used to treat the disease, but this therapy demands a complicated dosage regimen that is difficult to maintain and often causes severe side effects. 

According to the researchers, some physicians may unwittingly contribute to the drug-resistant epidemic if they don’t recognize the risks associated with incorrect use of the medications. 

“These drugs are as dangerous as chemotherapy,” said Dr. James Kahn of the University of California at San Francisco, a co-author of the paper. “General practitioners should not be using them. You really need a skilled HIV specialist to prescribe the medications and closely monitor the patient’s adherence and response to treatment.” 

In a commentary on the paper, Andrew Phillips of the Royal Free and University College Medical School in London said the findings shed light on a troublesome issue “and strategies must be developed and applied now if we are to preserve AIDS therapies for the future.” 

In their paper, the California team recommends steps to minimize drug-resistant HIV. 

• Delay drug treatment as long as possible in order to maximize the medical benefit and reduce side effects and the likelihood of developing drug resistance. 

• Create clinical centers of excellence for HIV/AIDS treatment to ensure proper use of drugs and limit the rate of acquired resistance. 

• Develop therapies that are more effective for treating patients with drug-resistant viral strains. 

Reduce the amount of time a drug-resistant patient is on ineffective treatment.