[The impact of viruses in lower respiratory tract infections of the adult. Part I: Pathogenesis, viruses, and diagnostics]

Abstract

In industrialised countries respiratory tract infections are one of the most common reasons for medical consultations. It is assumed that almost one third of these infections include the lower respiratory tract (LRTI), e. g. acute bronchitis, acute exacerbation of chronic obstructive pulmonary disease (COPD), community- or hospital-acquired pneumonia and influenza. Due to a lack of sufficient and valid investigations on the epidemiology of respiratory viruses, their impact on the pathogenesis of LRTI has probably been underestimated for a long time. Therefore, there might have been many cases of needless antibiotic treatment, particularly in cases of acute bronchitis or acute exacerbations of COPD, because of an assumed bacteriological aetiology. Following the introduction of diagnostic procedures with increased sensitivity, such as polymerase chain reaction, it is possible to reliably detect respiratory viruses and to illuminate their role in the pathogenesis of LRTI of the adult. We have reviewed the current literature to elucidate the role of viruses in the pathogenesis of LRTI. The first part of this series deals with the relevant pathogens, pathogenesis, and diagnostic procedures. In the subsequent 2 parts of this series a review will be given on the most common variants of viral LRTI (part II), and therapeutic and preventive options (part III).