Quantitative Pneumocystis jirovecii real-time PCR to differentiate disease from colonisation.

We studied a Pneumocystis jirovecii quantitative polymerase chain reaction (qPCR) for distinguishing P. jirovecii disease from colonisation. Eighty-two respiratory samples from 65 patients with qPCR results were analysed against a gold standard clinical diagnosis of Pneumocystis pneumonia.