GENEVA, Switzerland -- A team of AIDS researchers has reported a case in which a person has become infected with HIV that is resistant to six of the 11 approved HIV anti-retroviral drugs, including protease inhibitors. The investigators are from the University of California San Francisco AIDS Research Institute, ViroLogic, Inc., and the Centers for Disease Control and Prevention

Protease inhibitors have been approved for two years, and as part of triple combination therapies, have contributed to a dramatic decline in AIDS death rates. Protease inhibitors block construction of proteins the virus needs to build more copies of itself.

Transmission of drug resistant HIV has been reported previously, but only to anti-retrovirals known as reverse transcriptase inhibitors, which work by blocking the replication of the virus. They have been in use for more than 10 years, but are less effective treatments.

The transmission of protease inhibitor resistant strains of HIV to a previously uninfected person could represent an emerging clinical and public health problem because protease inhibitors are a powerful weapon in the arsenal against HIV, said Frederick Hecht, MD, assistant clinical professor of medicine at the UCSF-affiliated San Francisco General Hospital, and lead author of the study. The case study was reported by Hecht here today (July 1) at the 12th World AIDS Conference. Research results also will be published in the New England Journal of Medicine, currently in press.

The multi-drug resistant HIV strain is believed to have been transmitted from one person to another through unprotected anal intercourse. Multiple mutations of HIV are required for the virus to become resistant to protease inhibitors, according to Hecht, and it had been thought that those mutations might make it more difficult for the virus to reproduce and make transmission between people less likely.

"We still don't know how frequently resistant strains are transmitted," he sa
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Contact: Mitzi Baker
mabaker@itsa.ucsf.edu
(415) 476-2557
University of California - San Francisco
1-Jul-1998