There are some limitations to the study. First, the change of anti-infective management was retrospectively matched with the date of the rtPCR analysis. Exact time specifications were not available, leaving room for potential inaccuracies. It is not known whether and to what extent these or other factors contributed to the clinical decisions in starting, stopping, or continuing antibiotic therapy. Due to the retrospective nature of the study, it was not possible to consider the clinical presentation in the analysis. Therefore, it was difficult to reproduce the decision-making process and the primary indication for antibiotic therapy. This is an important limitation because clinical judgement remains essential concerning the use of antibiotics . Furthermore, data on the consequences of rtPCR results on antibiotic treatment are difficult to obtain in the ambulatory setting, which explains the relatively small number of enrolled outpatients. Prospective studies or ideally RCTs will be necessary to confirm the findings.