IMPORTANCE OF LEGIONELLA PNEUMOPHILA IN THE ETIOLOGY OF SEVERE COMMUNITY-ACQUIRED PNEUMONIA IN SANTIAGO, CHILE.

Chest

PubMedID: 23764871

Arancibia F, Cortes CP, Valdés M, Cerda J, Hernández A, Soto L, Torres A. IMPORTANCE OF LEGIONELLA PNEUMOPHILA IN THE ETIOLOGY OF SEVERE COMMUNITY-ACQUIRED PNEUMONIA IN SANTIAGO, CHILE. Chest. 2014;145(2):290-6.
ABSTRACT BACKGROUND In US and European literature Legionella pneumophila is reported as an important etiological agent of severe community acquired pneumonia (CAP), but in Chile this information is lacking. The aim of this study was to evaluate the incidence of severe CAP due for this agent in Santiago, Chile, and identify predictors of Legionella severe CAP. METHODS A multicentric prospective clinical study lasting 18 months was conducted; it included all adult patients who were admitted for a severe CAP in the Intensive Care Units (ICU) of 4 hospitals in Santiago. We excluded patients who were immunocompromised, had been hospitalized in the previous 4 weeks or presented another disease during their hospitalization. All data for the diagnosis of severe CAP were registered and urinary antigens for L pneumophila serogroup 1 were determined. RESULTS 104 patients with a severe CAP were included, mean age: 58.3 ±19.3 years; 64.4% males; APACHE II score was: 16.7± 6.3; SOFA: 6.1± 3.2, Pitt Bacteremia Score (PBS): 3.4± 2.5 and PaO2/FiO2: 170.8± 87.1. An etiologic agent was identified in 62 patients (59.6%): S. pneumoniae 27 (26%) and L. pneumophila 9 (8.6%) were the most frequent agents. Logistic regression analysis showed that plasma sodium = 130 mEq/L was an independent predictor for L. pneumophila severe CAP (OR 11.3; 95% CI 2.5-50.5; p= 0.002). Global mortality was 26%, and 33% for L. pneumophila. PBS and Pneumonia Score Index were better predictors of mortality. CONCLUSIONS We found that in Santiago L. pneumophila was second to S. pneumoniae as etiological agent of severe CAP. Severe hyponatremia at admission appears as an indicator for L. pneumophila etiology in severe CAP.