Catia Cilloniz1, Cristina Dominedò2, Albert Gabarrús1, Carolina Garcia-Vidal3, José Becerril4, Diego Tovar4, Estela Moreno3, Juan M Pericás5, Carmen Rosa Vargas1, Antoni Torres6. 1. Department of Pneumology, Hospital Clinic of Barcelona, August Pi i Sunyer Biomedical Research Institute - IDIBAPS, University of Barcelona, Biomedical Research Networking Centers in Respiratory Diseases (CIBERES) Barcelona, C/ Villarroel 170, 08036 Barcelona, Spain. 2. Department of Shock e Trauma, San Camillo Forlanini Hospital, Rome, Italy. 3. Department of Infectious Diseases, Hospital Clinic of Barcelona, Spain. 4. National Polytechnic Institute, Ciudad de México, México. 5. Clinical Direction of Infectious Diseases and Microbiology, IRBLleida, Universitat de Lleida, Lleida, Spain. 6. Department of Pneumology, Hospital Clinic of Barcelona, August Pi i Sunyer Biomedical Research Institute - IDIBAPS, University of Barcelona, Biomedical Research Networking Centers in Respiratory Diseases (CIBERES) Barcelona, C/ Villarroel 170, 08036 Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Spain. Electronic address: atorres@clinic.cat.
Abstract
OBJECTIVES: We aimed to describe the prevalence, risk factors and outcomes of Methicillin-susceptible S. aureus (MSSA) community-acquired pneumonia (CAP) and compare them with those associated with CAP due to Streptococcus pneumoniae, the most frequent causative microorganism, in a large cohort of patients. METHODS: This was an observational study of prospectively collected data of consecutive adults with CAP and a definitive etiology enrolled between 2004 and 2018. Patients were divided into MSSA CAP and pneumococcal CAP groups for analysis. RESULTS: A microbial etiology was established in 1,548 (33%) cases: S. aureus caused 6% of microbiologically-confirmed CAP cases. In the latter, 52 were due to MSSA (60% of S. aureus CAP cases, and 3% of microbiologically-confirmed CAP cases) and 34 were due to MRSA (40% of S. aureus CAP cases, and 2% of microbiologically-confirmed CAP cases). S. pneumoniae was identified in 734 (47%) microbiologically-confirmed CAP cases. The presence of fever was independently associated with a lower risk of MSSA CAP (OR 0.53; 95% CI, 0.28-0.99). Patients with MSSA CAP had higher 30-day mortality than patients with pneumococcal CAP, both before and after adjustment for potential confounders (21% vs 7%, p = 0.002). MSSA was independently associated with 30-day mortality in the overall population. CONCLUSION: MSSA CAP was associated with worse outcomes than pneumococcal CAP in our cohort. MSSA was an independent factor of mortality.
OBJECTIVES: We aimed to describe the prevalence, risk factors and outcomes of Methicillin-susceptible S. aureus (MSSA) community-acquired pneumonia (CAP) and compare them with those associated with CAP due to Streptococcus pneumoniae, the most frequent causative microorganism, in a large cohort of patients. METHODS: This was an observational study of prospectively collected data of consecutive adults with CAP and a definitive etiology enrolled between 2004 and 2018. Patients were divided into MSSA CAP and pneumococcal CAP groups for analysis. RESULTS: A microbial etiology was established in 1,548 (33%) cases: S. aureus caused 6% of microbiologically-confirmed CAP cases. In the latter, 52 were due to MSSA (60% of S. aureus CAP cases, and 3% of microbiologically-confirmed CAP cases) and 34 were due to MRSA (40% of S. aureus CAP cases, and 2% of microbiologically-confirmed CAP cases). S. pneumoniae was identified in 734 (47%) microbiologically-confirmed CAP cases. The presence of fever was independently associated with a lower risk of MSSA CAP (OR 0.53; 95% CI, 0.28-0.99). Patients with MSSA CAP had higher 30-day mortality than patients with pneumococcal CAP, both before and after adjustment for potential confounders (21% vs 7%, p = 0.002). MSSA was independently associated with 30-day mortality in the overall population. CONCLUSION: MSSA CAP was associated with worse outcomes than pneumococcal CAP in our cohort. MSSA was an independent factor of mortality.