An application of PIXE in medicine: Legionnaires' disease

Abstract

The name “Legionnaires' disease” refers to an acute respiratory illness that was first recognized at an American Legion Convention in Philadelphia in July, 1976. 221 people became ill and 34 died. During the ensuing months before the etiologic agent, a previously unknown species of bacterium, was isolated, many investigators suspected that a toxic agent, in particular nickel carbonyl, might have caused the outbreak of illness. We describe the use of proton-induced X-ray emission (PIXE) to analyse the nickel concentrations of the autopsy specimens. We show that the high nickel concentrations in the lung specimens were due to contamination during the autopsies. Recently we have used PIXE to show that the selenium concentrations in the serums of the acutely ill Legionnaires' patients are significantly lower than in their matching convalescent-phase serums. This finding may be related to the patient's response to the disease or to the specific characteristics of the Legionnaires' bacterium itself.