Pubdate: Tue, 26 Feb 2002 Source: Wall Street Journal (US) Copyright: 2002 Dow Jones & Company, Inc. Contact: http://www.wsj.com/ Details: http://www.mapinc.org/media/487 Author: Mark Schoofs RESEARCHERS TRACK HEPATITIS C, AIDS EPIDEMICS THROUGH CHINA SEATTLE -- By genetically fingerprinting the AIDS and hepatitis C viruses, researchers from China and New York have shown that the world's most-populous nation is suffering from distinct epidemics of these blood-borne microbes. Separately, another team of researchers showed just how fast HIV mutates, finding that it evolves far more swiftly than the influenza virus. The Yunnan province in the southwest region of China abuts the Golden Triangle, a major source of heroin . Here, the HIV and hepatitis C epidemics are driven by injection drug users, who share infected needles. In this region, a strain of HIV, called subtype C, extends north from Yunnan along the old Silk Road, which is now used by drug couriers. Similarly, the hepatitis C virus, called HCV, is dominated in this same region by a strain called subtype 3. But in the heartland of China, in the Henan province south of Beijing, the epidemic has been spread largely by contaminated blood donations. Illegal blood centers paid donors for blood, and some of these donors were infected with HIV and HCV. Here, the HIV subtype is predominantly B, and the HCV subtypes are largely 1 and 2. Yunnan province is inhabited by some of China's ethnic minorities, and the region is marked by low incomes and education, said Yunzhen Cao, a researcher with China's National Center for AIDS Prevention and Control and a visiting scientist at the Aaron Diamond AIDS Research Center in New York. In the past, the Chinese government has thwarted prevention programs, such as needle exchanges, known to slow the spread of HIV among drug users. But Dr. Cao said the government has recently allowed some pilot needle-exchange programs to start up, as well as AIDS education for commercial sex workers. She also said the government has cracked down on illegal blood centers. The study was presented here at the 9th Conference on Retroviruses and Opportunistic Infections by Linqi Zhang of the Aaron Diamond Center, which is laying the groundwork for possible trials of an AIDS vaccine and which has helped start AIDS treatment trials in China, run by Dr. Cao. In a separate study, Douglas Richman of the University of California revealed the startling ability of HIV to mutate its outer envelope. That is the part of HIV targeted by the immune system's antibodies, which snare free-floating virus. "We see in six months in one patient what happens to the influenza virus around the globe in a decade," said Dr. Richman. That presents a challenge to vaccine makers, who hope to stimulate antibodies that neutralize HIV by binding to its envelope. But Dr. Richman saw hope in his study. The fact that HIV mutates rapidly means antibodies are placing "incredibly strong selective pressure" on the virus, forcing it to keep changing to elude the immune system's powerful antibodies. But, said Dr. Richman, if a vaccine could induce such antibodies before the virus got a foothold inside the body, then maybe they could repel an infection. - --- MAP posted-by: Keith Brilhart