[The new comprehension of pulmonary infections]

Epidemiological data on the distribution of mostly bacterial pathogens are still the basis for empirical treatment recommendations on respiratory infections. Because of the dynamic technological developments in molecular multiplexing and sequencing procedures, the spectrum of potential pathogens is increased and challenges the current dogma of virulence and pathogenicity of certain pathogens. Classical pathogens of the lungs are thereby not questioned but are increasingly placed in a context that reflects co-infections with viruses and changes of the local microbiome in more depth. Recent data indicate that integration of this novel information is required for a better understanding of the seasonal differences in the frequency of particular lung infections and to find new approaches to risk stratification of patients. This becomes most obvious in the subgroup of immunosuppressed patients who are at risk of severe courses of diseases with higher morbidity and mortality from infections with viruses and facultative pathogens, such as nontuberculous mycobacteria (NTM). Based on the fundamental knowledge on the spectrum of pathogens of community-acquired and nosocomial lung infections, novel approaches in pathogen diagnostics and lung microbiome analytics are discussed and the applicability with respect to the current clinical routine is questioned.