Five years ago, few people had heard of AIDS. Now, it is seen as one of the greatest health threats facing the modern world. According to some medical sources, there could be 10,000 deaths in the UK from AIDS by 1990, with a further two million people carrying the virus. Yet attitudes to this killer disease are today dominated by ignorance and fear. AIDS has been described as 'God's gift to bigotry': from the gay community in particular come increasing reports of discrimination and violent attacks. Jeremy Paxman reports on the causes and the consequences of present attitudes to AIDS. He meets people with the virus and those working to help prevent the spread of a disease which, in the United States, already affects over a quarter of a million people.