Chapter 34 : Legionella Pneumonia: Three Cases in an Oncological Hospital

Abstract:

Legionella pneumophila is known as an important cause of nosocomial pneumonia. This chapter discusses three cases in an oncological hospital. A 47-year-old woman with malignant non-Hodgkin lymphoma, was hospitalized for more than 10 days, treated with high-dose chemotherapy. During treatment she developed a pneumonia, with a positive urinary Legionella antigen test (Biotest enzyme immunoassay urinary Legionella antigen). Despite therapy with macrolides and fluoroquinolones, the patient died from respiratory failure 1 week after the diagnosis. Immediately after the detection of the first case of Legionella pneumonia, the water distribution system was sampled in several sites, including the shower in the patient’s room, the intake from the municipal water supply, the water storage tank, and some distant outlets. A therapy with macrolides and fluoroquinolones was effective in curing another patient with high-risk breast carcinoma being treated with high-dose chemotherapy. It is remarkable that the diagnosis has always been performed by the detection of the urinary Legionella antigen, although the colonizing subtype was of the serogroup 2-14. A 54-year old man had received appropriate chemotherapy and general condition was improving, but at the end of the month, the patient developed Legionella pneumonia, as documented by a positive urinary Legionella antigen. Despite macrolide and fluoroquinolone treatment, the patient died 5 days later. The flush and heat decontamination method is not effective in eradicating L. pneumophila from the hot water distribution system, and it is therefore mandatory to keep surveillance measures for early diagnosis and prompt treatment of possible new cases.