A network of testing centres throughout Africa is reporting prevalence rates for HIV which were unheard of just five years ago. The worst fears of the 1980s are being realised in the Africa of the late 1990s. Over the past decade, the Aids virus has swept south from its stronghold in central Africa to create new and frighteningly dramatic inroads into the sexually active populations of southern Africa.
Life expectancy - a key measure of development - is already tumbling as a result of accelerating death rates in all sub-Saharan countries ranging from Angola to Zimbabwe. Aids has now overtaken malaria and tuberculosis as the leading cause of death in Africa. By next year nearly two-thirds of Botswanan children under five will die of Aids.
Unlike the infectious scourges of the past, which took their toll mainly on the very young and very old, Aids is devastating the most economically active members of the population, the young adults and skilled workers on which Africa's fragile economies depend. In Malawi, nearly one in three teachers were found to be infected with HIV.
Aids has already created 8,200,000 orphans in the world, most of them in Africa. By next year the UN Aids Programme expects there to be 13 million Aids orphans. In Uganda, one of the first countries to experience an Aids epidemic, 11 per cent of children are Aids orphans - compared with a typical orphan rate of 2 per cent. In Zimbabwe, where one quarter of the general population is infected, between 40 and 50 per cent of pregnant women are HIV positive - threatening a further big increase in the number of orphans.
Teenage girls in Africa are the most vulnerable section of society, being six times more likely to be HIV positive than boys of the same age. A study in Kenya found that 25 per cent of girls between 15 and 19 were infected with HIV. In South Africa, infection rates among girls the same age have increased from 12.7 per cent in 1997 to 21 per cent in 1998 - one of the fastest rates of HIV increase anywhere in the world.
Ignorance is another barrier. There is a common myth in several African nations that a man infected with HIV can cure himself by having sexual relations with a virgin, thus increasing the toll on young girls.