Abstract Introduction Legionella species are uncommon but important causes of atypical community-acquired pneumonia (CAP). The species is implicated in around 4-5% of all CAP, although cases are likely underdiagnosed given limitations in identifying non-serogroup 1 species 1,2. Cases of Legionnaire’s disease are classically taught as pneumonia with hyponatremia and gastrointestinal symptoms, but severe cases with fulminant extrapulmonary disease have been reported ats case here?. Here, we present a critically ill patient with severe pneumonia with multisystemic complications secondary to Legionella gormanii infection. Case Report A 65-year-old male shipworker with no significant past medical history was transferred to our intensive care unit from Mexico. He originally presented with myalgias and was found to have pneumonia with severe acute hypoxic respiratory failure. Initial infectious testing, including blood and sputum cultures, respiratory viral panel, and Legionella urine antigen testing, was negative. His course was complicated by hyponatremia, acute liver injury, splenomegaly, pancytopenia, and myocarditis. His occupational exposure in the shipping industry and systemic findings raised concern for Legionnaires’ Disease despite negative initial testing. Subsequent PCR and next-generation sequencing revealed Legionella gormanii. Both azithromycin and respiratory fluoroquinolones are efficacious. Our patient was treated with levofloxacin, extended to a fourteen day course upon pathogen identification due to severity of disease. His condition steadily improved, and his laboratory derangements eventually normalized. He was discharged with home oxygen. Discussion We present this case to encourage consideration of Legionellosis in patients with severe CAP and extrapulmonary involvement, especially in cases with hyponatremia, liver injury, splenomegaly, pancytopenia, and myocarditis. Legionella pneumophila serogroup 1 is responsible for 80-90% of all cases. While standard Legionella urine antigen testing is reasonably reliable for serogroup 1, it has been shown to have a sensitivity of less than 50% for other strains 2,3. This case highlights the limitations of standard testing and underscores the importance of pursuing appropriate empirical treatment and advanced molecular diagnostics when clinical suspicion for Legionnaires’ disease remains high. Prompt identification and treatment can be life-saving and may prevent fulminant extrapulmonary disease. References: 1. doi:10.3390/ijerph19031907, 2. doi:10.1016/S1473-3099(14)70713-3, 3. doi:10.1086/341087 This abstract is funded by: None
Ward et al. (Fri,) studied this question.