Throughout the 1990s Chinese officials denied they had an AIDS problem. But even then it was believed China had nearly 1 million infections.

AIDS arrived in China through the black market drug trade.

Vast fields of poppies supplying most of the world's heroin-based drugs are grown in the "Golden Triangle" -- a border area just south of China's Yunnan province where Laos, Burma and Thailand meet. The trafficking and injection of these drugs -- 60 percent of which travels north through Yunnan -- brought HIV into China.

The virus has now reached all 31 Chinese provinces. World Health Organization figures suggest the number of infections in China ranges from 840,000 to 1.5 million. As of February 2006, experts estimate that 200 Chinese are infected per day.

As with most countries, AIDS spread in China because of social and economic problems. High unemployment fosters a large migrant population and a boom in commercial sex work. Overall, the most common way AIDS has spread is intravenous drug use -- which accounts for more than 50 percent of all cases -- but patterns of transmission vary from region to region.

In some provinces, sales of tainted blood account for the majority of cases. Just a decade ago, after most developed countries had realized the perils of paid blood donation, Chinese officials continued to urge poor, rural Chinese to sell their blood for extra income. TV commercials assured donors that the process was safe, but in practice, poorly regulated and non-sanitary clinics led to rapidly spreading outbreaks of many diseases, including HIV. In some villages, where 95 percent of adults were donating blood regularly, up to 60 percent of the population became infected. China continues to face lingering problems with selling blood, even though the practice is now illegal.

But medically, the greatest problems China faces in confronting its AIDS epidemic are the massive reorganization of the nation's health care system and continuing ignorance about the disease. Government-controlled health care has given way to a decentralized system where clinics and doctors are expected to earn a profit. In this climate, reports are emerging of doctors who view an AIDS diagnosis as a moneymaking opportunity. They subject patients to needless expensive tests and admit them to the hospital to receive sub-par care until the patients have no more money to spend. A Global Fund grant of $95 million is being used to supply free antiretroviral drugs to up to 30,000 Chinese, but doctors under pressure to bring paying patients into hospitals are hesitant to publicize free treatment.

Medical understanding of AIDS also lags. Doctors admitting HIV-positive patients to hospitals for treatment may instruct staff not to touch them. Or, they may not know how to properly administer the antiretroviral drug regimen. Witnessing this lack of correct, up-to-date knowledge had a profound effect on Dr. David Ho, director of the Aaron Diamond AIDS Research Center and one of the world's foremost AIDS experts. Born in Taiwan, Dr. Ho is dedicated to bringing global attention to the AIDS crisis in China and finding ways to proactively control the epidemic. Recalling an April 2005 visit to a Chinese clinic treating AIDS patients, Dr. Ho says, "It was certainly reminiscent of what we went through in the early 1980s [in the U.S.]. These people were emaciated, had all sorts of complications, despite the fact that we have drugs that could treat them." To combat these medical failings, Dr. Ho presents conferences to teach Chinese doctors more about AIDS and its treatment.

As Dr. Ho realized, compared to the well-publicized epidemic in Africa, AIDS in China has received relatively little international attention. This has been due in part to the nation's hesitance to acknowledge the problem. The Chinese government first openly addressed AIDS as a national crisis in 2001. Since then, President Hu Jintao and Premier Wen Jiabao have paid high-profile visits to AIDS patients. The government has begun welcoming foreign aid and launched its own programs to combat the epidemic's spread.

Dr. Ho is hopeful that China will aggressively address AIDS, particularly following its recent experience with SARS. "This wake-up call caused by SARS focused attention on health matters," he explains. "... [The government] said, 'Wait a minute, by comparison SARS is dwarfed by AIDS. And therefore, [AIDS] has to be a higher priority.'"

Although the government is finally taking important steps to combat ignorance -- including distributing more than 1 billion free condoms each year and handing out decks of playing cards with information on safe sex and HIV to long-distance truck drivers -- doubts remain as to whether China is being completely open about the epidemic. Last fall, the government announced a new estimate of Chinese AIDS cases, putting the total number of infections at roughly 650,000. Authorities claimed the downward revision was due to previously overestimating the impact of a tainted blood scandal, but questions remain over whether the smaller number was politically motivated. The government has also tried to censor news of recent blood sale scandals, and NGOs advocating for AIDS patients' rights and better treatment must meet in secret, risking arrest.

China's decentralized decision making makes it hard to know if the government's efforts to fight AIDS will be effective. Implementation may be uneven across provinces and localities, and despite recent laws banning discrimination against HIV- or AIDS-infected individuals, the disease's stigma remains a major obstacle."Thomas," who runs a shelter in China for homeless individuals infected with HIV, and who is himself HIV-positive, agreed to an interview with FRONTLINE but withheld his real name for fear of exposing his status. "If I had cancer I could ask friends, ask my relatives, to get money [for medicine]," he says. "But for HIV/AIDS you can't tell anyone. You have to keep the secret by yourself." Thomas has faced even more challenging burdens in his efforts to help others with HIV, recalling, "I had an experience two years ago when I was running a shelter for homeless people living with HIV and AIDS -- when the neighborhood found out who we were and what we were doing there, we were kicked out three times in the first three months."

By 2010, China is projected to reach 10 million cases of AIDS if no effective intervention is undertaken. Given the country's massive population, even 15 million AIDS cases would constitute only 2 percent of the adult population. But dealing with such a high number of infections would require massive resources and personnel. AIDS continues to compete with other pressing concerns -- economic growth, rural discontent, modernizing the military -- for the Chinese government's money and attention. And among the Chinese people, AIDS has not yet become a popular rallying cause. But there are signs the public is no longer complacent about the disease. There have been reports of protests sparked by AIDS-related concerns in rural areas, and if these protests ever spread to urban areas, the government would have to react decisively.

The first step to effectively controlling the virus in China may be going back to the source, attacking the heart of the epidemic in the brothels, drug dens and migrant communities of Yunnan province, along the border with the Golden Triangle. This area is already receiving significant international attention and help: The Clinton Foundation is distributing free antiretroviral drugs to children, and UNICEF has launched an educational program targeting young adults who may be attracted to migrant work, prostitution, or drug use. Last year it became legal for foreign aid groups to promote condom use and testing among sex workers, and also to give out clean needles. Dr. Ho regularly visits clinics in this area, and the doctors there are confident they can win the fight against AIDS.

But China's push for economic growth could still undermine these successes. Plans are underway to expand the highway system near the Golden Triangle and this could speed the spread of HIV and AIDS out of Yunnan province to the rest of the country.

* Note: Figures reflect most recent statistics from UNAIDS and the World Health Organization.

• Related Links
• Living with AIDS:"Thomas"
  Here is an interview with "Thomas" (not his real name), a young man in China who struggled to find a way to get antiretroviral treatment as he approached death. Now he works to make sure other HIV-positive Chinese don't have to fight as hard as he did.
• UNAIDS Country Report: China
  This page has UNAIDS statistics on HIV/AIDS in China, an epidemiological fact sheet and analysis of the problem. It notes that China has made "good progress" in responding to HIV/AIDS, but that "It is feared that the number of people living with AIDS in China could reach 10 million by 2010 if the epidemic is left unchecked."
• Global Health Reporting: China Profile
  This site provides a basic by-the-numbers overview of China's HIV/AIDS epidemic. It also features a well-edited list of links to other sites about the disease's impact in China and to the Kaiser Foundation's archive of news items about China's epidemic from sources around the world.
• The China AIDS Initiative
  Founded by Dr. David Ho and coordinated by the Aaron Diamond AIDS Research Center, the China AIDS Initiative (CAI)"is working to produce dramatic and sustained interventions that will greatly reduce the size of what could otherwise become a devastating AIDS epidemic." This site features descriptions of CAI's programs and partners and a brief video about HIV/AIDS in China.
• China AIDS Info
  China AIDS Info provides an extensive library of links to news about HIV/AIDS in China, mostly culled from Chinese news sources and usefully sorted into the categories of General HIV/AIDS, Treatment, Prevention and Law and Policy.