Non-Pneuomophila Legionnaires' Disease in Cancer Patients

Abstract Non- pneumophila Legionella species are rare atypical bacterial pathogens that are responsible for a minority of Legionnaires' disease cases. Compared to Legionella pneumophila , they are more likely to infect immunosuppressed patients, such as those undergoing treatment for hematological cancers. This paper describes 3 cases of cancer patients who were effectively treated for pneumonia caused by non- pneumophila species, definitively identified via culture or microbial cell-free DNA (mcfDNA) analysis. This paper also compiles a list of other reported cases of cancer patients diagnosed with non- pneumophila Legionnaires' disease. Although diagnosis of pneumonia by a non- pneumophila Legionella species is challenging with currently available techniques, recommended antibiotic regimens are well established in the literature. Although they statistically appear to be uncommon pathogens, non- pneumophila Legionella species should be considered as possible causes when treating immunosuppressed patients with unspecified pneumonia.