China has defied calls to lift its ban on foreign visitors with HIV-AIDS ahead of the Olympics, highlighting a restriction that critics say fuels prejudice against those with the disease.

Despite last week removing a ban on visitors with leprosy entering the country -- a move state media highlighted ahead of next month's Games -- the long-time block on people with HIV or AIDS remains in place.

The ban would mean that basketball legend Earvin "Magic" Johnson -- who won an Olympic gold with the US "Dream Team" in Barcelona in 1992 a year after announcing he had contracted HIV -- would not be allowed entry to Beijing as a tourist.

Connie Osborne, a senior World Health Organisation's advisor on HIV-AIDS in China, said she had hoped that China would review the "sensitive issue" ahead of the Games.

She added that reducing the stigma of HIV sufferers was one of the most crucial steps in China addressing its patchy record on the disease.

"That is still an ongoing battle. We have won a few battles, but we have also lost a few," Osborne, a Zambian doctor, told AFP.

"When we do not address stigma and discrimination, people who may be affected and those at high risk tend to go underground," she added.

Despite the difficulties, Osborne said China had made real progress in other areas, in particular increasing awareness at a local level and improving the quality of treatment in the worst hit provinces, such as Henan and Yunnan.

"We have seen increased commitment by local government. When I first came it was just central government," said Osborne, who has been here from more than three years.

Organisers of the International AIDS Conference, which is set to meet in Mexico City from August 3 to 8, have condemned countries which refuse to lift travel restrictions.

"International AIDS Society (IAS) member experts in infectious disease and public health have long held that laws and policies barring the entry, stay or residence of HIV-positive people do not protect the public health and may in fact impede effective responses to HIV," the organisation said in a recent statement.

More than 20,000 professionals from around the world will gather to discuss the global response to HIV-AIDS at the conference.

Currently, some 67 countries have some sort of HIV-specific laws that restrict the entry of people living with HIV, although the United States has recently made significant moves towards lifting its ban.

China requires short-term entrants to declare their HIV status at the border, while long-term stays require compulsory tests, according to the Global Database of HIV-related travel restrictions.

Neither China's ministry of health nor the foreign ministry answered AFP questions about the ban, and visa application forms on the foreign ministry website still included the HIV question.

Zhu Jing, a spokeswoman for the Beijing organisers, said athletes and delegates would not have to give their HIV-AIDS status.

"For the Olympic family members, if he or she is an AIDS patient, he or she can still come to Beijing," she told AFP.

The latest study by China's ministry of health, along with the WHO and the United Nations, found that 700,000 people were HIV positive in China at the end of 2007, although campaigners have warned the figure could be up to 10 times higher.

Thousands were infected during the 1990s through tainted blood transfusions at illegal blood collection stations, but the focus of attention is now shifting to high risk groups such as gay men and sex workers.

China has made moves to improve its understanding of the gay community -- homosexuality was still considered a mental illness until 2001 -- one of the areas where it is approaching international norms, Osborne said.

There has also been a new emphasis on addressing the rising number of heterosexual infections, often among migrant workers in large cities.

However, progress is undermined by China's aggressive stance on any help from groups outside the ruling communist structure, in particular non-governmental organisations.

Activist Hu Jia, who has been one of the government's most vocal critics over the AIDS issue, was this year sentenced to three and a half years in prison on charges of inciting subversion of the state, while other lawyers and campaigners have faced harassment.

Fewer people are dying of AIDS, more patients are on HIV medication and the global AIDS epidemic is stable after peaking in the late 1990s.

But the United Nations AIDS agency warned in its yearly report Tuesday that governments will need to continue setting aside millions of dollars for AIDS in the coming decades as patients live longer on AIDS treatment.

"We've achieved more in the past five years than in the previous 20 years," said Peter Piot, the agency's executive director. "But if we relax now, it would be disastrous. It would wipe out all of our previous investments."

UNAIDS estimates the number of AIDS case worldwide at 33 million; its previous estimate of 40 million was revised last year because of changes to how it counts cases.

Countries in sub-Saharan Africa including South Africa, Botswana and Swaziland, remain the center of the AIDS epidemic. The region has about 67 percent of all people infected with HIV and 72 percent of all AIDS deaths.

Outside sub-Saharan Africa, AIDS mainly affects drug users, gay men and sex workers.

Officials estimate that 2 million people died from AIDS last year, down from approximately 2.2 million in 2005.

The most dramatic figures are in treatment: The number of people on AIDS medication jumped by 10 times in the last six years, with some 300,000 taking AIDS drugs in 2003 compared to about 3 million in 2007. AIDS drugs have become much cheaper and more available because of a variety of government and private programs.

But millions of others still do not have access to the drugs, and those who do will need to remain on them to stay alive.

Still, millions of new cases of HIV infection are reported every year, the agency said. HIV is rising in several countries beyond Africa, including China, Germany, Indonesia, Russia and Britain, according to the report, which was issued in advance of next week's international AIDS conference in Mexico City.

The good news is that the global number of new infections was down to about 2.7 million people in 2007 from a peak of about 5 million new cases annually in the early 2000s.

However, the report — based on government data from 147 countries — warned there could be future waves of infection. The agency said it would be difficult to predict whether the AIDS epidemic might spike again.

Experts said it's too early to stop worrying about AIDS.

"I'm not sure we will ever get to a point where we can say this is not a public health problem," said James Chin, a clinical professor of epidemiology at the University of California, Berkeley.

Last week, the U.S. government tripled the amount of money it will spend on AIDS and other diseases around the world to $48 billion over five years.

"The objective of AIDS programs is to provide access to medication to everyone who needs it," Chin said. "Until that's accomplished, this won't go away."

The slow decline of AIDS-related deaths is "dismally disappointing," said Selina Lo, medical coordinator for Medecins Sans Frontiere's Access to Essential Medicines campaign. The group also is known as Doctors Without Borders.

She called it evidence that strategies need to change.

Some experts said health officials know what to do — but still aren't doing things like spending more money on prevention.

"We just don't know how to get governments to do nice things for junkies, sex workers and gay boys," said Elizabeth Pisani, a former UNAIDS epidemiologist who wrote a book about the mistakes made in AIDS programs.

One of the largest conferences in the 27-year history of AIDS was set to open here Sunday with an expected turnout of 22,000 scientists, policymakers and grassroots workers.

The International AIDS Conference, which is held every two years, runs in the Mexican capital until Friday, and coincides with a relative lull in the war against the disease.

The theme, "Universal Action NOW," reflects an appeal to political leaders to maintain the momentum that began to build in mid-decade and has transformed access to precious antiretroviral drugs in poor countries.

A ceremonial concert late Sunday was to give the gathering the official kickoff, but workshops, seminars and other activities began several days before the start.

VIPs include former president Bill Clinton, a key figure in the campaign to slash the price of anti-HIV drugs to developing countries which are home to 90 percent of the 33 million people with the AIDS virus .

Insiders said they did not expect any breakthrough announcement in the arena of drugs, and braced for confirmation that the quest for a vaccine and an HIV-thwarting vaginal gel was mired in setbacks.

More positively, though, evidence has emerged that male circumcision can help prevent HIV infection among men -- a finding of great significance in southern Africa, the epicentre of the pandemic.

More than 25 million people have died from AIDS and 33 million today have the virus that causes it, according to UN figures.

US health authorities acknowledged Saturday that they had substantially underestimated the number of new HIV infections in the country.

About 56,300 people were infected with the virus that causes AIDS in 2006, a figure 40 percent higher than the previous estimate of 40,000 new infections a year, the US Centers for Disease Control and Prevention said in a study.

Thanks to a major increase in funding and cuts in the price of first-generation antiretrovirals, nearly three million needy people in developing countries have access to the lifeline drugs.

The triple "cocktail" rolls back the virus, thus helping to restore the immune defences, but does not completely eradicate the pathogen.

"There has been a spectacular advance, but we are still very short of the mark," Jean-Francois Delfraissy, head of France's National Agency for AIDS Research (ANRS) told AFP.

"One of the tasks of the conference is to address the fact that there are three million people who now get the drugs, but another nine million who do not."

According to UN agency UNAIDS, around 10 billion dollars was spent last year fighting AIDS in poor countries, but this was eight billion dollars short of what was needed.

Simply to maintain the current pace of drug access will require funding to rise by 50 percent by 2010. Even more will be needed to meet the goal of universal access, set for that year by the UN General Assembly.

The rising costs of keeping people alive under antiretroviral treatment -- a daily regime of pill-taking that has to be maintained for the rest of the patient's life -- is likely to revive focus on preventing the spread of the virus.

Workshops at the conference, the 17th in the series, will focus on exploring new ways, and on swapping ideas, for preventing transmission of the virus among intravenous drug users, people with multiple sex partners and other vulnerable groups.

HIV infection rates among gay men in many parts of Asia are as severe as those which devastated US homosexual communities in the late 1980s, top officials of the UNAIDS agency said here Tuesday.

Launching his agency's 2008 report on the global AIDS epidemic, Peter Piot, UNAIDS executive director, urged more action to prevent the spread of the disease among gay men who have unsafe sex and stressed the importance of working with affected communities.

"All over Asia there are now epidemics of HIV in men who have sex with men of the same magnitude that we saw in this country 25 years ago," Piot said.

"That is something that has been detected fairly recently. There is not enough action yet but we are now starting programs," he added.

Paul De Lay, director of Evidence, Monitoring and Policy at UNAIDS, said the HIV epidemic among gay communities in Asia was not new, but that it had recently reached the levels seen in cities such as San Francisco at the end of the 1980s when HIV infections reached their peak.

He said it could be due to a number of factors, including less funding for programs that target men who have sex with men and the fact that there were new groups who were less aware of the risks of unprotected sex.

"Asia has recognized populations of men who have sex with men for quite some time," he told AFP. "The epidemic in these populations started in the mid-1990s. What we see now is a resurgence."

"There are countries where the percentage of people infected are similar to what we were seeing in San Francisco or in Berlin or in London where up to 15 to 20 percent of men who have sex with men are HIV positive," he added.

The report meanwhile noted that unprotected sex between men was a "potentially significant but under-researched aspect of the HIV epidemics in Asia," citing countries such as Thailand and Vietnam.

"Recent study data from several major cities in the region, from Bangkok to Ho Chi Minh City, show increasing HIV prevalence among men who have sex with men," the report said.

In China, unsafe sex between men could account for up to seven per cent of HIV infections, it noted.

De Lay said there were also high infection rates among gay populations in cities such as Chennai and Mumbai in India and in Indonesia's capital Jakarta.

He added that these communities often faced homophobia from the wider population, as well as discrimination from health care providers, which discouraged them from seeking information and getting tested.

"Even without blatant national laws that criminalize homosexual behavior, you can still have a gradation of policies and practices that can be almost as bad," he said.

De Lay pointed to a similar resurgence of HIV infections among gay populations in the US and western Europe, which he said showed the need for constant vigilance.

The report said higher risk unprotected sex among gay men in several countries in western Europe, such as Germany, appeared to be linked to the increasing numbers of new HIV diagnoses among that group.

"It's disturbing because it's this sense that we can never let our guard down as far as prevention, that the epidemic will come creeping back if there isn't this constant attention being paid to it," De Lay said.

The UN AIDS chief said Tuesday that the global fight against the disease has made progress but voiced concern over rising cases in parts of the world, including Russia and Eastern Europe.

"The overall finding of the report is that we've made enormous progress, that there are real results," Peter Piot, executive director of UNAIDS, told a press conference as he released the agency's 2008 report.

"We have achieved more in the fight against AIDS in the last two years than in the preceding 20 years," he added.

However, the report cautions that the epidemic is not over in any part of the world and Piot said there were still five new infections for every two people who were put on treatment.

The report points out that rates of new HIV infections are rising in many countries such as China, Indonesia, Kenya, Mozambique, Papua New Guinea, Russia, Ukraine and Vietnam.

"I'm still very pessimistic about what is going on in Russia and Eastern Europe," Piot said. "That's the region of the world where there's the least progress."

In 2007, an estimated 1.5 million people in Eastern Europe and Central Asia were living with HIV, more than double the figure in 2001 when an estimated 650,000 people were HIV-positive, the UNAIDS report said.

The largest HIV epidemic in the region is in Russia and almost 90 per cent of those infected in the region live in either the Russian Federation or Ukraine, it added.

Piot said that the number one problem in Russia was injecting drug use but added that he was concerned that methadone was still illegal there.

"As long as that's illegal there's no way we can bring this epidemic under control," he said. "That's not a matter of money. That's a matter of political leadership and changing the policy."

Launching what he called "undoubtedly the most positive report" that the organization had issued, Piot said there had been unprecedented leadership in the fight against AIDS over the last two years, with a substantial increase in HIV treatment and prevention.

According to the 2008 'Report on the global AIDS epidemic,' the number of new infections has declined in several countries, such as Rwanda and Zimbabwe, due to changes in sexual behavior.

Among young people, condom use is increasing, they are waiting longer to have sexual intercourse and report having fewer sexual partners.

From 2005 to 2007, the percentage of HIV-positive pregnant women receiving antiretroviral drugs to prevent transmission of the virus to their children increased from 14 percent to 33 percent, while the number of new infections among children declined from 410,000 to 370,000.

Four out of every five Kenyans living with HIV are unaware of their status and about two-thirds of the country's 37 million people have never been tested, a study released Tuesday said.

The Kenya AIDS Indicator Survey said 57 percent of HIV-positive people said they had never taken an AIDS test while 26 percent said they were HIV negative but later tested positive.

"As many as four out of five HIV-infected persons do not know their status," the report said.

"Nearly two-thirds of Kenyans report never having tested for HIV and are therefore unaware of their status," it added.

National Aids Control Programme chief Ibrahim Mohamed said "sixteen percent did not want to know their test results or were afraid others would know the results."

Another "fourteen percent were unaware of the test for HIV or where to get tested and five percent cited distance to testing (centres) as a major barrier."

Some 1.4 million Kenyan adults are living with the HIV/AIDS.

The survey, carried out between August and December 2007, is the first since 2003. It did not include children.

"We have made notable progress, however HIV/AIDS rates among our families and communities remains unacceptably high and the impact severe," Health Minister Beth Mugo said at the launch of the report.

Around 33 million people worldwide were living with HIV in 2007, two million of whom were children and another two million died of AIDS-related causes, according to a report released Tuesday by the UNAIDS.

However deaths from AIDS-related illnesses fell last year for the second year running mainly due to the widening distribution of drugs, it said.