China, having finally broken its silence about AIDS, must now expand its struggle against the disease nationwide but faces challenges in prevention and treatment, UNICEF said on Thursday.

Experts have faulted China for being slow to recognise a growing AIDS problem, exacerbated by the cover-up of botched blood-selling schemes in the central province of Henan that infected scores of people in the mid-1990s.

The government has estimated China has 840,000 people with HIV or AIDS, but activists and experts say a more accurate figure would be between 1 million and 1.5 million.

“I think China has at least broken through the silence barrier, but having broken through the silence barrier it now has to take AIDS on as a China-wide challenge,” UNICEF executive director Carol Bellamy said in a speech in Beijing.

She warned that “prevention, services, information and treatment are all remaining challenges for China”.

Bellamy urged more efforts in ensuring a clean blood supply and in preventing cross-border transmission of the disease.

In a speech to a forum dedicated to “A Decade of Achievement for Children”, Bellamy said the most serious challenge for children worldwide was HIV/AIDS “and the many terrible ways that is has redefined childhood”.

“I sincerely believe that most people do not really comprehend just how many young lives have been transformed for the worse by HIV/AIDS, and how many millions more are under threat,” she said.

“HIV/AIDS has redefined childhood illness; it has redefined child labour; it has redefined sexual abuse; it has redefined family. Indeed it has redefined the nature of hope itself, and it is marching onward from Africa to Russia, India, and even to China,” said Bellamy.

Bellamy spearheaded UNICEF’s response to the Asian Tsunami, and on Thursday accepted a cheque for $6.5 million from the Chinese government for the tsunami appeal.