2225. Are Fluoroquinolones or Macrolides Better for Treating Legionella Pneumonia? A Systematic Review and Meta-Analysis

Abstract Background Reported cases of Legionella pneumonia continue to rise in the United States; with mortality rates of 9–25%. The Infectious Disease Society of America recommends either a fluoroquinolone or azithromycin as the first-line treatment for legionellosis. While treatment of Legionella pneumonia improves outcome, it is uncertain as to which antibiotic offers optimal clinical outcomes. We undertook a systematic review and meta-analysis to compare the effectiveness of fluoroquinolone vs. macrolide monotherapy in Legionella pneumonia. Methods We conducted a systematic search of literature in multiple databases through April 2019. Studies on patients diagnosed with Legionella pneumonia and treated with either antibiotic of interest were included. Mortality was used as the primary outcome to compare fluoroquinolones and macrolides. Secondary outcomes were clinical cure, time to apyrexia, length of hospital stay (LOS), and the occurrence of complications. We estimated pooled odd ratios to compare the odds of death, clinical cure, and complications. The standard mean difference was estimated for LOS and time to apyrexia. We used a random-effects model and estimated heterogeneity using the I2 statistic. We also analyzed the risk of mortality by setting, i.e., intensive care unit (ICU) vs. non-ICU studies. Results Of the 1,583 abstracts reviewed, 20 studies with a total of 3,656 patients met inclusion criteria. The mean age of the population was 60.9 years and 68.5% were men. The mortality rate for patients treated with fluoroquinolones was 7% (102/1454) and 7.7% (125/1615) among those treated with macrolides. The overall pooled odds ratio (OR) assessing mortality risk for patients treated with fluoroquinolones vs. macrolides was 0.95 (95% CI 0.71–1.27, I2 = 0%, p = 0.54). Odds ratios for subgroup analyses were: ICU studies (OR = 1.27, 95% CI: 0.18–9.08, I2 = 45%, p = 0.158); non-ICU studies (OR = 0.96, 95% CI: 0.71–1.32, I2 = 0%, p = 0.616) (figure). Clinical cure, time to apyrexia, LOS, and the occurrence of complications did not differ between fluoroquinolones and macrolides. Conclusion Fluoroquinolones and macrolides were found to have similar effectiveness in treatment of Legionella pneumonia for mortality outcomes. However, insufficient data for secondary outcomes was a limitation of this analysis. Disclosures All authors: No reported disclosures.