Communication is the basic precondition of a global society. At the same time, however, communication is a basic cause for today's health hazards and diseases. This is an experience of our time, it is a historical experience of social change as well. If a global society wants to survive, the existing hazards to life and health have to be understood and treated on a global scale. Apart from a "new morbidity" and chronic diseases also infectious diseases again require more and more attention even in industrialised countries. The history of public health offers an overwhelming expertise of well-established concepts for every imaginable risk, to handle infectious diseases which are either not yet or no longer controllable on an individual therapeutical level. History of medicine also shows, that the effectiveness of hygienic concepts is based on their scientific validity and the resulting predictability of their interventions. This implies, that modern hygiene has to incorporate actively the concept of molecular medicine. Every single discipline involved, i.e. hygiene/sanitation, toxicology, microbiology, bacteriology, immunology, and infectiology, has to join in interdisciplinary scientific and interventional efforts.