Figure 1.

Inclusion of samples and patients *Some patients have positive isolates from more than one type of specimen ICU, Intensive care unit; PCR, Polymerase chain reaction; BAL, bronchoalveolar lavage. The flow chart shows inclusion, exclusion, and results of virological and microbiological analyses in number of patients. Data are presented as frequencies and percentages. Only the throat swab collected at admission was kept for study purposes. Retrospective reviewing of the sample indications led to the exclusion of 37 patients.