Table 3.

Clinical Classification of Patients Based on Integration of Test Results with Clinical Judgment

Uninfected: No evidence of CAP

Post-admission clinical, laboratory, and imaging studies document an alternative non-infectious diagnosis: e.g., congestive heart failure.

Pure Bacterial Pneumonia

Proven: A compatible clinical syndrome (fever, cough, new pulmonary infiltrates, elevated white blood count) with detection of only bacterial pathogen(s) by one or more of: Biofire® Respiratory FilmArray®, NP S. pneumoniae PCR, nasal swab for S. aureus PCR, urine antigens, sputum and/or blood culture, or BPFA.

Presumptive: Clinical CAP syndrome with compatible chest radiographic abnormalities without detection of a potential bacterial pathogen by any of the same tests listed in the last paragraph. A PCT level ≥0.25 ng/ml with no other explanation was interpreted as presumptive evidence of invasion by an undetected bacterial pathogen.

Pure Viral Pneumonia

Presumptive: High probability of viral pneumonia based on compatible clinical presentation, detection of a virus by the BioFire® Respiratory FilmArray® or BPFA absent detected bacterial pathogen by FilmArray®, and serum PCT level <0.25 ng/ml.

Viral and Bacterial Co-Infection

Presumptive: Detection of a virus by either the BioFire® Respiratory FilmArray® or BPFA. In addition, detection of a bacterial pathogen in sputum and/or blood cultures, urine antigen tests, the Biofire® Respiratory FilmArray®, the BPFA, the nasal swab for S. aureus and/or the NP PCR for S. pneumoniae.

Pneumonia of Unclear Etiology

Clinical criteria for CAP but no bacterial or viral pathogen detected by any test and no non-infectious disease diagnosed.

NP = nasopharyngeal; PCR = polymerase chain reaction; PCT = procalcitonin; BPFA = BioFire® Pneumonia FilmArray®