<br/>Scientists say, Anti-retroviral treatments (ARVs) could stop the spread of Aids in South Africa within five years. Dr Brian Williams said, the drugs reduce the amount of virus patients have in their body fluids. He said the scale of the problem in South Africa is enormous as 30 million people are infected with HIV and two million people dying each year. By providing HIV positive patients with these drugs could stop the spread at a cost of around dollar 2-3 billion per year, he added. Dr Williams, a leading figure in the field of HIV research, is based at the South African Centre for Epidemiological Modelling and Analysis (Sacema) in Stellenbosch.<br/><br/>Dr Williams called for this approach at the annual meeting of the American Association for the Advancement of Science in San Diego.