It has been 20 years since the start of the global AIDS epidemic. The U.N. report says the disease has become the single biggest threat to African development. The report says 40 million people are living with AIDS worldwide - 70 percent of them live in sub-Saharan Africa. That is more than 28 million people.

A pregnant young woman receives her HIV results during a counselling session in Botswana Credit: UNAIDS/G. Pirozzi

In the year 2001, five million people worldwide became infected with HIV, the virus that causes AIDS. Sixty-eight-percent of them were in Africa. That means 3.4 million Africans contracted the virus this year.

Two-point-three-million Africans died of AIDS-related illnesses this year -more than three-quarters of all AIDS-related deaths in the world.

The United Nations report says African children under the age of 15 are particularly hard hit. Of all children in the world living with HIV, 88 percent are African. Worldwide, 800,000 children became infected this year; 700,000 of them were in sub-Saharan Africa - more than 87 percent.

The report says worldwide, 580,000 children died of AIDS in 2001 - 86 percent of them were African.

John Ohiorhenuan represents the U.N. Development Program in South Africa. He says the epidemic is hurting every part of African society. "The update indicates that as the epidemic spreads, so does its impact on development of societies, and the well being of countries. In sub-Saharan Africa, the hardest hit countries could lose more than 20 percent of their GDP (gross domestic product) in 20 years," he said. Southern Africa has long had the highest rates of infection on the continent. The report says in Swaziland, Botswana, and some parts of South Africa, more than 30 percent of pregnant women are HIV positive.

But the problem is growing in West Africa. The U.N. report says infection rates exceed five-percent in several West African countries, including Nigeria - the most heavily populated nation on the continent.

Part of the problem is a lack resources. Few Africans have access to the lifesaving drugs that allow AIDS patients in the West to live near-normal lives.

Another problem is a lack of education about the disease. In some countries, the report says many people have never even heard of AIDS. It says many others have serious misconceptions about how it is spread. Without that information, people cannot protect themselves from HIV.

But there are some signs of hope. The report singles out Senegal, Uganda, and Zambia as relative success stories.

It says Senegal has managed to keep its infection rate low, in part thanks to strong political support for prevention efforts. Similar political will has allowed Uganda to dramatically reduce its infection rate, which was once among the highest in the world.

Mr. Ohiorhenuan says Zambians are now beginning to change their sexual behavior, and HIV prevalence is falling in urban areas. "A new study in Zambia shows urban men and women reporting less sexual activity, fewer multiple partners, and more consistent use of condoms," he said.

U.N. officials say part of the reason Zambia has been able to begin turning its AIDS epidemic around is because the disease has claimed so many lives. They say Zambians have begun to realize the disease affects everybody, not just people with HIV.

But political will is also a key. Mr. Ohiorhenuan also gives credit to the Zambian government's massive, long-term campaign to raise AIDS awareness. "[It] is the sustenance of that campaign of talking people, of reinforcing the importance of behavioral change is finally beginning to show effects. Which, I may add, is a good sign because it means it is possible in other places, but that the effort needs to be maintained," he said.

He emphasizes that kind of success does not happen overnight. But the U.N. report says the political will to turn the tide of AIDS appears stronger than ever.

It urges governments to quickly develop effective prevention programs, particularly targeting young people. It also calls for greater access to treatment and care.