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A5530 - Clinical Features of Legionella Pneumonia in a Community Hospital
Author Block: M. Momose, H. Nagano, Y. Nei, S. Yamashiro, T. Kishaba; Department of Respiratory Medicine, Okinawa Chubu Hospital, Uruma, Japan.
Introduction: Legionella pneumonia is known as a cause of atypical pneumonia which is transmitted by aerosol and often present as severe pneumonia. We investigated clinical features of legionella pneumonia in our hospital. Method: We examined the medical charts of the patients who were hospitalized due to legionella pneumonia in our hospital from January 2007 to August 2017 retrospectively. Results: We found 30 patients who were admitted because of legionella pneumonia. The average age of the patients was 69.6 year old (38-102 year old). The male were 25 and female were 5. The most frequent symptom was fever (77%). There were 9 patients (30%) who had a water contact such as hot spring, well, river, pond, humidifier, tank, and bedrock bath. 17 patients (57%) had crackles, which included holo-inspiratory crackles (43%) and late-inspiratory crackles (13%). 13 patients (43%) showed absence of crackles. In diagnostic method, 18 patients (60%) were positive for urine antigen of legionella (antigen positive group). 12 (40%) patients were negative for urine antigen of legionella (antigen negative group). The antigen negative group was clinically diagnosed as legionella pneumonia because of the history of water contact, altered mental status, hyponatremia, elevated liver enzyme, and the clinical course that cephalosporin antibiotics didn’t affect. Compared to the antigen positive group, antigen negative group was more likely to have higher CPK (1166 vs 675.8) and lower P/F ratio (214 vs 243). The antigen negative group was more likely to have pleural effusion than the antigen positive group (58% vs 39%). However, the duration of oxygenation was shorter in the antigen negative group than antigen positive group (5.6 vs 9.5 days). There were no differences of mortality. There were 26 patients (87%) who survived (survivors). 4 patients (13%) passed away due to respiratory failure (non-survivors). Compared to the patients of survivors, patients of non-survivors were more likely to be older (86.8 vs 67 year old) and had lower P/F ratio (135 vs 251). In addition, duration of oxygenation was longer in the patients of non-survivor than those of survivor (10 vs 2.5 days). However, elevation of liver enzyme, hyponatremia, and extra-pulmonary symptoms such as altered mental status and diarrhea were more likely to be seen in the patients of survivors. Conclusion: In the patients of legionella pneumonia, we have to be careful for the elderly patients with low P/F ratio.