"This second wave is tough, it's a challenge for us," Wu admitted.

He spelt out a battery of measures that the authorities had adopted since 2004, a year that campaigners agree is a watershed in China's history of dealing with AIDS.

Spurred by a top-level AIDS Working Group under the aegis of the State Council, funding for AIDS has risen sharply, from 20 million dollars a year in 2002 to 100 million dollars in 2005.

Tests for HIV are free, as is treatment with antiretroviral drugs; laws have been introduced to bar discrimination and protect patients' data; and the government is vigorously promoting the use of condoms and AIDS awareness through posters, advertisements and broadcast shows.

Ninety-two sites have been set up where drug addicts can swap used needles for clean ones, a figure that will rise to 1,400 over the next three years, and the country had implemented special legal provisions to give heroin addicts the safer substitute of methadone.

But Wu acknowledged that there remained big problems, especially in access to HIV tests. Only 145,000 of the estimated 650,000 HIV-positive individuals had actually been tested, he said.

Researchers who carried out an intensive test campaign in Yunnan detected 13,486 people with HIV in just six months, only slightly less than the tally of 14,905 that was reached over the previous 17 years.

And, he admitted, homophobia and stigma meant that tackling HIV among men who have sex with men was "a headache for us."

Veterans in the war on AIDS have given China high marks for ditching secrecy and denial as its response to the epidemic.

Some, though, challenge the accuracy of China's data, say its distribution of antiretroviral drugs is timid -- 26,000 now have access to the lifesaving treatments, a figure scheduled to rise to 30,000 by year's end -- and question how far the writ of Beijing extends in distant, rural regions.

Former US president Bill Clinton, in a speech at the International AIDS Conference on Tuesday, was warm in his praise.

"China, once in a state of denial, deserves all of our respect for turning on a dime and acknowledging the problem and approaching it systematically," he said.

Clinton recalled how the Chinese government invited him to tour rural China last year, asking him to meet people with HIV to help combat AIDS stigma.

"(The Chinese government) jokingly said to me, 'Oh, well, I know you think we're an undemocratic country and we're an authoritarian country, but, believe it or not, we can't order people to change their minds and hearts.'"