THE EPIDEMIOLOGY OF LEGIONELLA PNEUMONIA: 5-YEAR REVIEW

Abstract

SESSION TITLE: Chest Infections Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Legionella is an intra-cellular bacterium that can cause community acquired pneumonia. The infection is water-borne and does not spread from patient to patient. L. pneumophila, is responsible for approximately 90% of all reported cases of legionellosis. The clinical presentation of Legionnaires' disease is variable with multiple extra pulmonary manifestations. The aim of this study is to describe the epidemiology of Legionella over a five-year period. METHODS: A retrospective analysis of Legionella cases between 2015 and 2019 was conducted utilizing electronic medical records. Patients were identified based on their urinary Legionella antigen test. The records were reviewed for demographic data, social risk factors, clinical, laboratory and radiographic criteria. Simplified acute physiology score (SAPS) II, intensive care unit (ICU) admission, length of stay (LOS) and mortality were also collected. Analysis of the data was performed using Stata Statistical Software V. 14.2. utilizing standard statistical tests for comparing continuous and categorical variables. RESULTS: The study identified 3956 patients who had Legionella urine antigen testing between January 2015 and December 2019. There were only 39 (1%) patients who returned positive. The mean age of the patients was 61.9 ± 13.5 with slight increase in men. There was a gradual increase in the number of cases over the years. The mean LOS was 7.7 ± 5.6 days (ICU patients had a mean stay of 11.1 ± 6.2 vs the medical floor which had a LOS of 4.3 ± 1.9 days). 26 (74.3%) patients were smokers. The median creatinine on admission was 1.3 (1.0-1.9) and Na was 132.0 (128.0-137.0). The mean SAPS II score was 14.2 ± 14.4. CONCLUSIONS: There has been a steady increase in the cases over the years. Smoking remains as a major risk factors associated with Legionella pneumonia. Unlike what is classically reported in literature; hyponatremia was not a common finding and often mild. Radiographic findings were present in all cases on admission. Admission to ICU was common in Legionella pneumonia and is associated with significantly longer LOS. CLINICAL IMPLICATIONS: The rising number of cases of Legionella over the years is alarming. Half of the cases require ICU admission which makes testing for Legionella is extremely important. The diagnosis of Legionella pneumonia is dependent on urinary antigen testing. Legionella microbiology culture may be important to monitor the emergence of other Legionella serotypes not detected by urinary antigen test. DISCLOSURES: No relevant relationships by Firas Abdulmajeed, source=Web Response No relevant relationships by Waqas Bhatti, source=Web Response No relevant relationships by Jamil Masood, source=Web Response No relevant relationships by Marie Tuft, source=Web Response No relevant relationships by Mohamed Yassin, source=Web Response