[Possibilities and limitations in the localisation of sources of infections (author's transl)]

In latent microbial hospitalism environmental checks of the patients, the staff and objects permit detection of pathogenic or potentially pathogenic bacteria which are silent epidemiologically. "One's own body" as a source of infection has not yet been sufficiently investigated in connection with auto-infections. Taking two staphylococcal epidemics as examples, reference is made to the monogenic and heterogenic forms of hospitalism as well as to the necessity of accurately identifying the strains for the purpose of localising the source of infection. In the monogenic form only one type of bacterial species is present (Table 2). In heterogenic hospitalism, infections are caused by various different species of bacteria or also by a single species. If this is the case, various biotypes, serotypes and phagotypes exist (Table 1). In addition, simple possibilities of biotyping the staphylococci are demonstrated. Defensive measures can be adopted selectively only when the epidemiology and the source of infection are known.