Multiplex PCR for respiratory bacteria in acute care

The purpose of the study was to evaluate the clinical utility of multiplex PCR for detecting bacterial respiratory pathogens in nasopharyngeal samples. Acutely ill adults in the emergency department with respiratory infection symptoms, fever, chest pain or poor general condition were enrolled for this cohort study. Samples were stored at -70 °C until being analysed with multiplex PCR for seven respiratory bacteria. Of the 912 patients enrolled, those with positive bacterial samples (n = 130, 14%) were significantly younger than those with a negative finding (55.5 years vs 62.2 years, p < 0.001), and their mean C-reactive protein (CRP) concentration was higher (110 mg/L vs 59 mg/L, p < 0.0001). Patients with a positive respiratory bacterial finding had a higher probability of pneumonia (35% vs 13%, p < 0.001) and a higher likelihood of receiving a prescription for antibiotics than those with a negative finding (79% vs 59%, p < 0.0001). Positive detection of Streptococcus pneumoniae was associated with a 4.5-fold risk of pneumonia in a multivariate model and detection of an atypical respiratory pathogen with a 9-fold risk. Bacterial PCR performed on nasopharyngeal samples appeared to offer a valuable addition to the diagnostics of infections in adults in acute care.