An unexpected cause for cavitary pneumonia and empyema

Tularemia is an emerging zoonotic disease mainly of the Northern Hemisphere caused by the Gram-negative coccobacillus Francisella tularensis. It is affecting a wide range of animals and causes human disease after insect and tick bites, skin contact, ingestion and inhalation. A 66-year-old man presented to our clinic with cavitary pneumonia and distinct pleural effusion. After failure of empiric antibiotic therapy, thoracoscopic assisted decortication and partial excision of the middle lobe were conducted. Conventional culture methods and broad-range bacterial PCR including RipSeqMixed analysis were performed from the excised biopsies. Culture results remained negative but broad-range PCR targeting the first half of the 16S rRNA gene revealed F. tularensis DNA. This result was confirmed by F. tularensis-specific PCR and by serology. The source of infection could not be explored. To conclude, we report the rare clinical picture of a community-acquired pneumonia followed by pleural effusion and empyema due to F. tularensis. Broad range bacterial PCR proved to be a powerful diagnostic tool to detect the etiologic organism.