The Chest Radiographic Manifestations of Legionnaires' Disease in Taiwan: A Retrospective Study

Abstract

Objective To evaluate the chest radiographic manifestations of Legionnaires' disease in Taiwan. Materials and Methods From January 2003 to August 2008, we reviewed the chest X-rays of 53 patients from a medical center in east Taiwan with a diagnosis of Legionnaires' disease, confirmed by the Center for Disease Control and Prevention of Taiwan. We compared our results with those found in the current literature. Results Among the 53 patients, 44 (83%) had positive findings—shown by initial chest radiographs. Thirty patients (68%) were classified as having patchy airspace opacities, four (16%) had confluent opacities, and 11 (25%) had interstitial infiltrates. Three patients (7%) had mixed alveolar and interstitial patterns. In terms of distribution of the lesion, 23 (52%) were unilobar, 16 (36%) were multilobar and five (11%) were bilateral. The lower lobes were the most common location of involvement ( n = 32, 73%). Five patients (11%) had pleural effusion on presentation, but none of our patients had cavitations. Nine patients (17%) in our study had negative chest X-ray findings on initial presentation. Conclusion The radiographic manifestation of Legionnaires' disease in Taiwan is variable, ranging from normal to airspace consolidation, interstitial infiltrates, or mixed patterns. Although previously classified as atypical pneumonia, the most common radiographic findings are airspace consolidation, particularly unilobar, and located in the lower lobes.