Legionnaires' disease caused by Legionella longbeachae in Taiwan, 2006-2010.

The aim of the present study was to investigate the epidemiology of Legionnaires' disease (LD) caused by Legionella longbeachae in Taiwan during 2006-2010. A total of six cases were identified prospectively, accounting for 1.6% of all laboratory-confirmed LD cases and 4.4% of culture-positive LD cases. All six cases occurred between April and August. The male to female ratio was 0.5. These six LD patients had a higher median age than those with LD due to Legionella pneumophila. Four of the six patients presented with pleural effusion and five survived the infection episode. Only two patients had a potential soil contact history prior to LD onset. The patients resided in divergent geographical areas without a common exposure history. The individual genomic DNA banding patterns of the six L. longbeachae isolates analyzed by pulsed-field gel electrophoresis (PFGE) were unique, supporting the hypothesis that the L. longbeachae infections occurred sporadically.