The radiographic features of epidemic and sporadic Q fever pneumonia.

Radiographic dissimilarities exist between the chest radiographs of patients with epidemic and sporadically-occurring Q fever pneumonia. Chest radiographs of 25 patients with Q fever pneumonia were retrospectively assessed, and demonstrated previously unreported differences between these two broad groups. Differing strains of Coxiella burnetii, or varying doses of the pathogen, are postulated as the pathogenetic mechanisms for the observed discrepant findings.