[Etiologic characteristics of adult patients with community-acquired pneumonia in Beijing].

To explore the etiologic characteristics of adult patients with community-acquired pneumonia (CAP) in Beijing.A multicenter cohort of 510 adult CAP patients were enrolled from Beijing during the period of November 2010 to May 2012. Multiplex polymerase chain reaction (PCR), real-time fluorescence quantitative PCR and legionella urinary antigen were used to detect common respiratory viruses, Mycoplasma pneumoniae and legionella respectively. Bacteria were detected by sputum culture, blood culture and Streptococcus pneumoniae urinary antigen. Statistical analyses were performed for the etiologic characteristics and seasonal distribution of detected pathogens.Pathogens were detected in 240/500 (47.1%) study patients. The mixed infection of different pathogens was present in 42 cases (8.2%), viruses in 164 (32.2%), Mycoplasma pneumoniae in 91 (17.8%), bacteria in 26 (5.1%) and Legionella in 3 (0.6%). Among 164 patients infected with viruses, 194 viral strains were detected. Influenza virus represented the greatest proportion with 105 (54.1%) in viral infections. Between November 2010 to October 2011, Influenza A infections increased gradually in November 2010, peaked in February 2011 and declined by March 2011 in China. Mycoplasma pneumoniae was predominant in winter and spring.There is a high detection rate of virus and Mycoplasma pneumoniae in adult CAP patients in Beijing. And more consideration should be given to influenza virus and Mycoplasma pneumoniae infections in winter and early spring.