Community-acquired pneumonia in immunocompromised older patients: incidence, causative organisms and outcome.
Clin Microbiol Infect. 2012 Jan 10;
Authors: Sousa D, Justo I, Domínguez A, Manzur A, Izquierdo C, Ruiz L, Nebot M, Bayas JM, Celorrio JM, Varona W, Llinares P, Miguez E, Sánchez E, Carratalá J
Clin Microbiol Infect ABSTRACT: The number of elderly patients in the community with immunosuppressive conditions has increased progressively over recent decades. We sought to determine the incidence, causative organisms and outcome of community-acquired pneumonia (CAP) occurring in immunocompromised older patients. We prospectively compared cases of CAP in immunocompromised and non-immunocompromised patients admitted to five public hospitals in three Spanish regions. Of 320 cases studied, 115 (36%) occurred in immunocompromised patients, including: solid or hematological malignancy (97), corticosteroids or other immunosuppressive drugs (44), solid organ or stem cell transplant (five), and other conditions (eight). The etiology was established in 44% of immunocompromised patients vs. 32% of non-immunocompromised patients (p?0.03). Streptococcus pneumoniae was the most common causative organism in both groups (29% vs. 21%; p?0.08), followed by Legionella pneumophila (3% vs. 6%; p?0.01). Gram-negative bacilli were more frequent among immunocompromised patients (5% vs. 0.5%; p?<0.01), particularly Pseudomonas aeruginosa (3% vs. 0%; p?0.04). Nocardiosis was only observed in immunocompromised patients (two cases). Bacteremia occurred similarly in the two groups. No significant differences were found with respect to ICU admission (8%, in both groups) or the length of stay (12.5 vs. 10.4?days). The early (<48?h) (3.5 vs. 0.5%; p?0.04) and overall case-fatality rates (12% vs. 3%; p?<0.01) were higher in immunocompromised patients. In conclusion, a substantial number of older patients hospitalized for CAP are immunocompromised. Although relatively uncommon, CAP due to gram-negative bacilli, including P. aeruginosa, is more frequent among these patients. CAP occurring in immunocompromised patients causes significant morbidity and mortality.
PMID: 22390624 [PubMed - as supplied by publisher]