In Britain about 1700 people have now been diagnosed w i th AIDS o f w h o m about half have died, and recent estimates suggest that between 50,000 and 100,000 others may already have been infected by the Human Immunodeficiency Virus (HIV), the cause o f the syndrome. In the Uni ted States, more than 70,000 people have already been diagnosed w i th AIDS, o f whom over half are dead and when official estimates were last published (some two years ago), it was estimated that one-and-a-half to two mi l l ion Americans could be infected.