Impact of Routine Systematic Polymerase Chain Reaction Testing on Case Finding for Legionnaires’ Disease: A Pre–Post Comparison Study

Background. Legionnaires’ disease cannot be clinically or radiographically distinguished from other causes of pneumonia, and specific tests are required to make the diagnosis. Currently, testing occurs erratically and, instead, clinicians rely on empiric treatment strategies and ignore public health implications of the diagnosis. We aimed to measure the increase in case detection of Legionnaires’ disease following the introduction of routine polymerase chain reaction (PCR) testing of respiratory specimens. PCR is the most sensitive diagnostic tool for Legionnaires’ disease.