[New topics in infectious medicine (author's transl)]

After the eradication and control of the old classical epidemics, the situation in the sector of infectious diseases has changed. These days 3 groups of infectious diseases have gained importance than they had in the past and thus have changed the scene: I. Infectious diseases which earlier were either not known on such a scale or completely unknown Under this group fall mainly the "infectious factor diseases" caused by so-called "opportunistic" germs, mixed infections, old and new zoonoses, iatrogenic infections, "explosion epidemics" and epidemics caused by germ mutations. II. Therapy-resistant infectious diseases Here a distinction is made between infectious diseases caused by chemotherapy-resistant germs and the diseases whose increased rate of incidence is due to the fact that the arthropod vectors became resistant to insecticides. III. Infectious diseases to which the classical Henle-Koch postulates no longer apply These are chronic diseases and persistent infections, immunopathogenic consequences of infections and viral tumours. The diseases are discussed separately with respect to the cause/effect relationship with the emphasis on the following subjects: Opportunistic problem germs, infectious factor diseases with hospitalism, mixed infections, salmonellosis and new viral zoonoses, chronic diseases, "slow viruses", immunopathogenic consequences of infections and viral tumours.