Nairobi - The AIDS epidemic sweeping Africa is not only killing millions and tearing apart families - it is also crippling economic growth in a continent that is already the world's poorest. A UN report released yesterday said the cost of treating AIDS patients, the loss of experienced workers to the disease and subsequent restrictions on investment will all hamper economic growth in the decades ahead. That will undercut Africa's efforts to prevent the gap between itself and the rest of the world from getting even wider.