BEIJING (AP) -- Chinese health authorities and the U.N. AIDS agency pledged to fight discrimination against people with the disease in China with the unveiling Sunday of a massive red ribbon, the symbol of AIDS awareness, at the Olympic Bird's Nest stadium in Beijing.

Organizers said the fear of being stigmatized at work or in their communities is discouraging many people at risk of HIV infection from being tested. HIV is the virus that causes AIDS.

After years of denying that AIDS was a problem, Chinese leaders have shifted gears in recent years, confronting the disease more openly and promising anonymous testing, free treatment for the poor and a ban on discrimination against people with the virus.

State television Sunday showed Chinese Premier Wen Jiabao visiting a village hit particularly hard by AIDS in eastern China's Anhui province. Wen, who makes such annual visits to mark World AIDS Day, observed Monday, held hands with children orphaned by AIDS and spoke to patients in beds.

The topic, however, still remains very sensitive and authorities regularly crack down on activists and patients seeking more support and rights.

"About half of all Chinese would not want to share a meal with a person with HIV/AIDS, and a quarter would not want to shake hands," said Dr. Bernhard Schwartlander, country coordinator of UNAIDS in China. "People will not come forward to be tested. They won't benefit from treatment. They won't talk to their partners and colleagues about HIV/AIDS -- putting themselves and others potentially at risk for HIV."

Schwartlander was speaking at the Bird's Nest stadium, a main Olympic venue, during the unveiling of a 66-foot by 50-foot (20-meter by 15-meter) banner on which the red AIDS awareness ribbon was printed.

"Stigma and discrimination are major obstacles in an effective response to AIDS. We need to engage all sectors of society in China to combat these issues and work together to stop the disease," said Minister of Health Chen Zhu. He did not specify any steps they would take.

Official estimates put the number of people living with HIV in China at about 700,000, with around 85,000 people with full-blown AIDS, UNAIDS said in a statement. But the number of officially reported HIV cases remains only 264,302 -- far lower than the estimated total, in part because of reluctance to seek testing.

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