Rapid syndromic PCR testing in a Norwegian cohort with suspected community acquired pneumonia

<b>Background:</b> Most patients with community acquired pneumonia (CAP) are treated with empirical antibiotics. Lack of microbiological identification is a significant problem and enhanced pathogen detection could have a major impact. <b>Objectives:</b> To explore feasibility and diagnostic advantages of the BioFire^® FilmArray^® Pneumonia panel <i>plus</i> (FAP <i>plus</i>) in a clinical setting prior to testing in a randomized controlled trial. <b>Methods:</b> Prospective inclusion of patients with suspected CAP at the emergency department (ED), Haukeland hospital, Norway, during winter 2019/20. An induced sputum or endotracheal aspiration sample was analyzed by the FAP <i>plus</i>. Microbiological yield and turnaround time (TAT) were compared with standard diagnostics (SD). The relevance of detected microbes was deemed according to pre-specified criteria. <b>Results:</b> 96 patients had suspected CAP; 72 received a final diagnosis of CAP and 24 had other respiratory tract infections. Microbiological tests were positive in 89 (93%) patients, yielding a total of 179 detected microbes. Uncertain relevance was assigned to 63 (35%) microbes. The FAP <i>plus</i> and SD detected 91% and 55% of the total microbes, and 94% and 69% of the relevant microbes, respectively. <i>H. influenzae</i> (33%), <i>S. pneumoniae</i> (28%) and Influenza A virus (22%) were the most frequent pathogens. TAT was shorter for the FAP <i>plus</i> (2.7 h) than the main SDs (in-house PCR 24.1 h; positive sputum cultures 92.6 h). <b>Conclusion:</b> A syndromic PCR panel for respiratory pathogens increased microbiological yield and had short TAT. This suggests that syndromic PCR-based testing can be useful in an ED setting. Detection of microbes with uncertain clinical relevance needs further examination.