A report compiled by aid agencies, presented to the International Aids Conference in Barcelona, said extended families often fail to cope, and many children are forced to live on the street.

It says even if action is taken now, the number of orphans would continue to rise for many years.

The threat HIV poses was graphically illustrated by scientists at the conference who warned people who were already HIV positive should use condoms because there was a risk of them contracting another strain of the disease.

HIV/Aids has created an orphans crisis

Peter Piot, UNAids

The report from UNAids, the UN children's agency Unicef and the US development agency USAid looked at data for 88 countries in Africa, Asia, Latin America and the Caribbean.

The report "Children on the Brink" estimates that in 2001, 13.4m children, had lost one or both parents to Aids.

Sub-Saharan Africa, where 70% of people with HIV or Aids live, is set to be hardest hit in the future.

By 2010, an estimated 20m children - almost 6% of all the children in Africa - will be orphaned by Aids if present trends continue, the report estimates.

	:	Aids in Africa
Click to see Africa's growing epidemic

The total in Asia is set to double by 2010 to 4.3m.

But the report warned the total in Asia could be even greater because of indications the number of HIV cases in countries with large populations, such as China, India and Indonesia, are growing.

Significant increases are also predicted in Argentina, Brazil, Colombia, Guatemala and Mexico.

In Latin American and the Caribbean, there were 578,000 Aids orphans last year, 200,000 of them in Haiti alone. The prediction for 2010 is for the total to reach 898,000.

Stigma

Carol Bellamy, executive director of Unicef said children often suffer severe psychological and emotional problems.

Increases in Aids orphans

Global 2001 - 13.4m 2010 - 25m Africa 2001 - 9m 2010 - 20m Asia 2001 - 1.8m 2010 - 4.3m Latin America/Caribbean 2001 - 578,000 2010 - 898,000

Girls in particular may miss out on education, parental guidance and suffer social stigma, and fall into prostitution or crime.

She said although resources from rich countries were vital, local governments must help children by ending the stigma they face, and improving schooling.

Ms Bellamy told the BBC: "When the father dies, if there was any property in the family, in many countries, certainly in Africa, there is no inheritance, so it has implications.

"When the mother dies, the family virtually falls apart."

Where both parents die, the extended family often takes children in, with elderly grandparents or older children bearing the brunt of providing for a family.

If these networks of family support break down, orphans can be forced to live in the street.

Ms Bellamy added: "Even if prevalence rates of HIV in countries were to begin level off or even go down, we know that the increase of number of orphans would go on for a number of years."

Families 'crumbling'

She said the community, the family and particularly the young person themselves were crucial in tackling the problem.

"There's no question in some cases they're going to be on their own and trying to give them some life skills is going to be crucial."

She said private sector, political and religious leader had to recognise the long term impact of orphans on a countries stability and finances as an area where some of the greatest impact would be felt.

Peter Piot, executive director of UNAids, warned: "HIV/Aids has created an orphans crisis.

"In some countries, the very fabric of society is disappearing, and family structures are crumbling.

"The most catastrophic scenarios can be envisaged."

A special session of the UN general assembly last summer called on governments to draw up strategies for Aids orphans by 2003 and to implement them by 2005.

Safe sex

The danger of people already HIV positive being "super-infected" by another strain was outlined at the conference by Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases.

He said even couples where both partners were HIV positive should use condoms.

Dr Fauci said there had been cases where patients controlled their infection, until they were infected for a second time, when their condition deteriorated.

He said this could be because their immune system could not cope.

Dr Fauci said: "Although definitive data doesn't exist ,,, there are strong suggestions that someone infected with one virus and get 'super-infected' with another."