Ls. Tkatch et al., Epidemiology of Legionella pneumonia and factors associated with Legionella-related mortality at a tertiary care center, CLIN INF D, 27(6), 1998, pp. 1479-1486
Legionella pneumophila is an important pathogen that may cause nosocomial a
nd community-acquired pneumonia in patients with normal or altered immunity
. The epidemiology of 40 cases of legionella pneumonia in patients hospital
ized between 1986 and 1994 was studied. Fourteen patients (35%) were solid
organ transplant recipients. The calculated annual incidence of L. pneumoph
ila infection was highest among lung transplant recipients (2.07 cases per
1,000 transplant-years). There was a trend toward reduced mortality rates a
nd less severe disease among transplant patients vs. nontransplant patients
: mortality rate, 36% vs. 54%; incidence of intubation, 50% vs. 69%; rate o
f concurrent infections, 29% vs. 38%; and overall rate of complications, 86
% vs. 96%; respectively. In a multivariate analysis, factors independently
associated with an increased mortality rate were nosocomial acquisition, ne
ed for intubation, formation of lung abscess or cavitation, and presence of
pleural effusion. Thus, despite differing host immune responses, the most
important prognostic factors affecting the outcome of legionellosis are nos
ocomial acquisition and the development of pulmonary complications.