1/2. A profile of those individuals and their teams who are at the cutting edge of rapid-response epidemiology - who use their deductive skill to identify as well as contain outbreaks of infectious diseases. Vivienne Parry talks to key players from Atlanta's Centre of Disease Control, the WHO in Geneva and the UK's Health Protection Agency, and examines these organisations' attempts to establish a truly globalised disease detection and response network as a matter of real urgency. Producer Simon Hollis