Africa remains by far the world's poorest continent, with millions of its people living on less than $1 a day.
Iinfectious diseases pose a devastating threat to economic development, as well as killing many Africans each year, .
Malaria costs Africa up to $100bn a year in lost productivity, five times more than annual development aid received. The disease kills 1 million Africans a year, consumes 40% of the continent's health expenditure, and accounts for half of all hospital admissions.
"A lot of absenteeism is due to malaria at school and at work," says Ann Kichoi, a Kenyan health worker with Amref, which provides such simple preventatives as mosquito nets.
Nearly 10% of South Africa's work force has HIV. As a song by Zimbabwean musician Oliver Mtukudzi says, "Everyone around us is dying. Who will be left to mourn?Who will feed us when all the breadwinners are dying?"
About 28 million Africans are now living with HIV/Aids, which has become the biggest cause of death in sub-Saharan Africa, the UNAIDS agency calculates. The only imaginable catastrophe bigger than this "is the end of the world," says Dr Tom Mboya Okeyo, who heads Kenya's national Aids control programme.