Clinical features and predictors of mortality in admitted patients with community- and hospital-acquired legionellosis: A Danish historical cohort study

Abstract

BackgroundLegionella is a common cause of bacterial pneumonia. Community-acquired [CAL] and hospital-acquired legionellosis [HAL] may have different presentations and outcome. We aimed to compare clinical characteristics and examine predictors of mortality for CAL and HAL.MethodsWe identified hospitalized cases of legionellosis in 4 Danish counties from January 1995 to December 2005 using the Danish national surveillance system and databases at departments of clinical microbiology. Clinical and laboratory data were retrieved from medical records; vital status was obtained from the Danish Civil Registration System. We calculated 30- and 90-day case fatality rates and identified independent predictors of mortality using logistic regression analyses.ResultsWe included 272 cases of CAL and 60 cases of HAL. Signs and symptoms of HAL were less pronounced than for CAL and time from in-hospital symptoms to legionellosis diagnosis was shorter for CAL than for HAL (5.5 days vs. 12 days p < 0.001). Thirty-day case fatality was 12.9% for CAL and 33.3% for HAL; similarly 90-day case fatalities in the two groups were 15.8% and 55.0%, respectively. In a logistic regression analysis (excluding symptoms and laboratory tests) age >65 years (OR = 2.6, 95% CI: 1.1-5.9) and Charlson comorbidty index ≥2 (OR = 2.7, 95% CI: 1.1-6.5) were associated with an increased risk of death in CAL. We identified no statistically significant predictors of 30-day mortality in HAL.ConclusionsSigns and symptoms were less pronounced in HAL compared to CAL. Conversely, 30-day case fatality was almost 3 times higher. Clinical awareness is important for the timely diagnosis and treatment especially of HAL. There is a need for further studies of prognostic factors in order to improve the therapeutic approach to legionellosis and potentially reduce mortality.

Factors associated with hospital mortality in community-acquired legionellosis in France

“…The LD fatality rate ranged from 5-25% in immunocompetent hosts [16] to 33% in severe LD [17], 8.5% in a study by DOMINGUEZ et al [7] and 12.9% in the more recent investigation by JESPERSEN et al [18].…”

Nosocomial Legionnaires’ Disease: Risque and Prevention

“…The illness has become increasingly recognized, less severely ill patients are seen earlier in the course of the disease [65]. Thus, clinical manifestations (fever, headache, diarrhea, hyponatremia) of hospital -acquired Legionnaires' disease were found to be less pronounced than for those with community-acquired Legionnaires' disease [66]. Pneumonia is the predominant clinical syndrome.…”

“…The physical findings are those of pneumonia. The most common presentation of legionellosis is pneumonia which is often severe but almost any manifestation of the disease has been seen ranging from a mild self-limiting flu-like illness called Pontiac fever to any extrapulmonary affection to multi organ failure and death [66].…”

Legionnaires’ Disease and Use of Tumor Necrosis Factor-Αlpha Inhibitors: A Forthcoming Problem?

“…It is most frequently manifested as pneumonia (the so-called Legionnaires' disease), which is often severe, or as the so-called Pontiac fever (flu-like illness) [7]. Newer generation of macrolides and azalides (clarithromycin, azithromycin) and fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) has been shown to penetrate rapidly and achieve a high level of concentration in phagocytic cells [8], an attribute that makes them drugs of choice in Legionnaires' disease.…”

“…is one of the most common causative agents of community-acquired pneumonia (CAP): 2-15% of all hospitalized patients for CAP in Europe and North America are caused by Legionella [7], and recent studies suggest an increasing rate of legionellosis cases [9]. Legionella spp.…”