Use of multiplex PCR in pleural effusion: is it necessary to change the paradigm of culture-based methods?

The microbiological diagnosis of pleural effusion is based largely on classical microbiology methods, but these methods have a high rate of false negative results. Some previous studies have shown improved diagnostic performance for pathogens such as Streptococcus pneumoniae using molecular biology methods. We present the use of a multiplex PCR platform (BIOFIRE FILMARRAY Pneumonia Panel) for the aetiological diagnosis of pleural effusion in paediatric pneumonia. We present a case series of 17 pleural fluid samples that were processed by culture-based microbiology and molecular biology methods. Microbiological isolation was successful in four cases (25 %) through traditional culture methods. In contrast, the molecular biology panels allowed for detection in 16 out of 17 cases (94 %). The results from these panels led to a change in management for nine out of the 17 cases (52 %). This study found an increase in aetiological diagnosis in complicated pneumonia in children by using molecular biology methods, which led to a significant change in patient management.