The world must continue to strive for better containment of HIV/AIDS and increase its fight against discrimination, delegates to the 17th International AIDS Conference (IAS), which opened in Mexico City on Sunday, were told.

"This epidemic, the most complex, the most challenging and probably the most demanding infectious disease humanity has ever had to face, is far from over," Margaret Chan, director-general of the World Health Organization said at the opening session of the six-day event.

"We dare not let down our guard. This is an unforgiving epidemic," she said.

"We are going to be in this for the long haul."

Peter Piot, executive director of UNAIDS, agreed.

"The end of AIDS is nowhere in sight," he said.

"Every day, almost three times as many people become newly infected with HIV as those who start taking antiretroviral treatment."

As HIV infections are rising in countries where prevention had been thought successful, new epidemics are appearing, for instance, among gay Asian men and among drug users in parts of Africa, Piot said.

The resurgence of HIV infections in the gay community, which was the first to be hit by the virus in the 1980s, is a huge setback for disease prevention efforts, Chan said.

"We must remember every lesson learned," she said, adding that there is a global need for comprehensive sex education for sexually active young people who are vulnerable to the virus.

Also, "we should not forget vulnerable groups like gay people, intravenous drug users, and sex workers when it come to HIV prevention and control," she said.

The prevention effort must also include pushing for social change, Piot said.

There must be "no more stigma about HIV, no more homophobia, no more ostracism of sex workers", he said.

A local prostitute who asked not to be named, said: "We are not the source of AIDS."

The Mexico City conference is the first to invite sex workers to participate.

The event, which is held every two years, has attracted 26,000 scientists, policymakers and field workers from around the world. Its theme is "Universal Action Now".

This year's congress is the third for Wang Linhong of China's National Center for Women and Children's Health.

"The conference is a good opportunity to keep up to date and exchange views," she said.

Piot said that although the prevalence of HIV/AIDS was still low in China, the country still faces problems with containment.

"Not all (Chinese) governors see it as a big issue. They are afraid too much publicity will tarnish their image," he said.

(China Daily August 5, 2008)