[Etiology of community-acquired pneumonia among adult patients in Japan].

To clarify the etiology of community-acquired pneumonia (CAP) in Japan, the causative pathogens were prospectively investigated in adult patients admitted to Kurashiki Central Hospital. The microbiological diagnosis was based on the results of quantitative sputum culture, blood culture, and other invasive procedures, including transthoracic needle aspiration or bronchoscopic examination. Five hundred fifty-two episodes of CAP in 540 patients were admitted between July 1994 and June 1999. Causative pathogens were identified in 353 episodes (63.9%). Several characteristics about the etiology of CAP in Japan were recognized: 1) Streptococcus pneumoniae is the most common pathogen followed by Haemophilus influenzae; 2) Mycoplasma pneumonia is dominant among young patients; 3) Chlomydia pneumoniae is one of the significant pathogens in Japan as well as in western countries; 4) Streptococcus milleri group and anaerobes are important pathogens in patients with suppurative pulmonary diseases; 5) The incidence of Legionella pneumonia is far lower than in western countries; 6) The prevalence of tuberculosis in CAP is still high in Japan; etc. Recognition of these results will lead us to treat patients with prompt antimicrobial therapy.