Investigation of the causative agents for community-acquired pneumonia in adult patients

Aim: Community-acquired pneumonia (CAP) is a common condition in healthy people, causing morbidity and mortality worldwide despite latest advances in therapy and immunization procedures. Causative agents cannot be detected in approximately 50% of CAP episodes and therapy is initiated empirically. We aimed to determine the spectrum and frequency of the causative agents in patients with CAP in a university hospital.Materials and methods: Seventy seven adult patients hospitalized with CAP from November 2007 to March 2008 were included. CAP was diagnosed with clinical, radiological, and laboratory signs. Results: Sputum and blood cultures grew Streptococcus pneumoniae in 15 specimens; Haemophilus influenzae in 4,Klebsiella pneumoniae in 4, Staphylococcus aureus in 3, and Escherichia coli in 2. Mycoplasma pneumoniae DNA was detected in serum from 10 patients with RT-PCR. Legionella pneumophila urinary antigen was detected in 5 patients.Serological IgM antibodies to Chlamydia pneumoniae in 7 patients and Respiratory Syncytial Virus in 2 patients were observed. Etiology was not determined in 32.5% of patients. The most frequently identified pathogens causing CAP were S. pneumoniae, M. pneumoniae, and C. pneumoniae in descending order in our hospitalConclusion: Although determination of causative agents in all CAP patients has not been accomplished, knowledge of the spectrum and frequency of local causative agents are valuable for targeted therapy.