More than 12 million children in sub-Saharan Africa - equivalent to every child in Britain under the age of 15 - have been orphaned by AIDS, according to a report yesterday by the British charity, Christian Aid.
By 2010, that figure will have risen to 43 million children, by which time the virus will have cost the South African economy alone more than £15 billion, it warned.
Mr Mark Curtis, head of policy at the charity, said: "An entire generation is growing up without parents, without teachers, without a future."
Youngsters are often orphaned two or three times over as their parents die, and they are placed with aunts, uncles and other close relatives, who also fall victim to the disease.
Many are forced to take to the streets where they grow up in "an emotional and spiritual vacuum", the charity added in its report, entitled "No Excuses".
"Villages are becoming ghost towns; local economies are crumbling," it said.
"The orphaned children, as adults, will not be equipped to drive the economic engine of Africa.
"This will make the struggle for development and growth on the continent even tougher."
The charity said more than two million people in Africa died from AIDS last year and 25.3 million are living with the disease or its precursor, HIV.
In sub-Saharan Africa, 8.5 per cent of the population has the virus.
The International Monetary Fund and the World Bank have said that developed countries should be contributing 0.7 per cent of gross national product to development assistance by 2010 - the figure for Britain is currently just over 0.31 per cent.
The Archbishop of Canterbury, Dr George Carey, called the situation in Africa "a staggering problem".
He told BBC Radio 4's Today programme that the charity's "hard-hitting report" was directed at the government and the church alike. "A good, generous country looks beyond its borders to transform the world in which we live," Dr Carey said.