Just as H.I.V. destroys the body's immune system, the epidemic of H.I.V. and AIDS has disabled the body politic. As a result of H.I.V., the worst-hit African countries have undergone a social breakdown that is now reaching a new level: African societies' capacity to resist famine is fast eroding. Hunger and disease have begun reinforcing each other. As daunting as the prospect is, we will have to fight them together, or we will succeed against neither.
About 29 million Africans are infected with H.I.V. The epidemic is spread by heterosexual transmission almost entirely. Only 30,000 of these people are receiving antiretroviral treatment. Between three million and four million people are dying each year from AIDS-related diseases. Twenty percent of adults in South Africa live with H.I.V.; the figure is higher still in Botswana, where life expectancy has plunged below 40 years.
How do such realities relate to famine? Traditional agrarian societies in Africa were well adapted to the threat of drought. Food shortage was like a familiar virus, unpleasant and painful but one to which most people had resistance. For example, the victims of famine were almost exclusively young children and the elderly. Young adults rarely died - and women survived better than men. Society's core was preserved, and it could recover. Rural Africans were experts at surviving famine. Women knew exactly what wild grains, roots and berries could be eaten as famine foods when there was no maize. Families scattered their members over a wide area and called on distant relations for help when times got hard.
These coping skills meant that rural Africa was forgiving of the shortcomings of international relief programs. Typically, calls by the United Nations for food donations fall short of their goal by half or more. Yet the inhabitants of, say, Mozambique or Sudan have still pulled through. This is changing. We are facing a new variant of famine: in societies hurt by AIDS, famine is more deadly and less susceptible to existing treatments. The reason is that AIDS attacks exactly those capacities that enable people to resist famine.
AIDS kills young adults, especially women - the people whose labor is most needed. When the rains come, people must work 16 hours a day planting and weeding the crop. If that critical period is missed, the family will go hungry. In a community depleted by AIDS, each working adult must produce more to feed the same number of dependents - not just children but sick adults, too.
The burden of care for those sick with AIDS can cripple a family. Many employers - private and public - have withdrawn benefits. Town dwellers who fall sick go home to the village to pass their final months, to die and be buried. Children orphaned by AIDS are sent to the village to be cared for. There is a prevailing myth that the African extended family will cope with this double burden of care. We are learning the hard way that it cannot.
The drop in adult life expectancy also has implications that we are only just beginning to appreciate. The normal generational cycle means that assets like land and cattle are accumulated and handed down by the older generation. Grandparents can assist with child care; older women can pass on a lifetime's experience of gathering and preparing wild grains and fruits to their daughters. Today all this is interrupted. Young people are inheriting debts and are not learning essential skills. How can a young woman, looking after six children, have the experience and skill of her mother or grandmother in cultivating her field, collecting wild fruits and planning for survival through a tough year? And can she even make any plans on the premise that things will return to normal some day?
Finally, the first response of any adult faced with a harvest failure is to tighten her belt. Relief workers in Africa have become so used to this physiological resilience that they ignore adults' nutritional needs and just focus on children. But adult hunger is no longer a passing difficulty. A person living with H.I.V. needs better nutrition - more calories and especially more protein - to stay healthy. Malnutrition accelerates the progression to AIDS.
As their livelihoods collapse, their family networks fold and their coping strategies vanish, millions of young women are turning to what is called "survival sex" to feed their children. The consequences for H.I.V. transmission do not need to be spelled out.
In short, H.I.V. is imperiling the ability of African societies to reproduce themselves. Even when the rains come we will not see a return to normalcy but merely a breathing space. And we will be forced to appreciate just how different this crisis is.
Some senior United Nations leaders, notably Kofi Annan, the secretary general, have recognized the scale and gravity of the AIDS cataclysm and its link to famine. But the policy tools we have are blunt, fashioned for a different kind of crisis. We can't just ship in food. Food assistance and scaled-up antiretroviral treatment must go hand in hand. We need imaginative and large-scale responses to the burden of care: how to support the millions of people who are looking after dependent children (many of them orphans) and people with AIDS? We need to re-examine farming systems to put more money into farmers' hands and more protein on their tables. Above all, we need to restore a sense of the future to a generation facing an appalling crisis, to help unlock their energies in search of solutions.
Alex de Waal is director of Justice Africa and an adviser to the United Nations Economic Commission for Africa and Unicef.