Etiology and Outcome of Community-Acquired Lung Abscess

Background: Anaerobes are the first and Streptococcus species the second most common cause of community-acquired lung abscess (CALA) in the West. The etiologic pathogens of this disease have changed in Taiwan, with Klebsiella pneumoniae being reported as the most common cause of CALA. Objective: To determine the etiologies of community-acquired lung abscess. Methods: We retrospectively reviewed the records of 205 Japanese adult patients with CALA to evaluate etiologies and outcomes. We used not only traditional microbiological investigations but also percutaneous ultrasonography-guided transthoracic needle aspiration and protected specimen brushes. Results: Of these 205 patients, 122 had documented bacteriological results, with 189 bacterial species isolated. Pure aerobic, mixed aerobic and anaerobic, and pure anaerobic bacteria were isolated in 90 (73.8%), 17 (13.9%), and 15 (12.3%) patients, respectively. The four most common etiologic pathogens were Streptococcus species (59.8%), anaerobes (26.2%), Gemella species (9.8%), and K. pneumoniae (8.2%). Streptococcus mitis was the most common among the Streptococcus species. Mean duration of antibiotic administration was 26 days. Six patients Received: October 13, 2009 Accepted after revision: February 9, 2010 Published online: April 10, 2010 Noboru Takayanagi Department of Respiratory Medicine Saitama Cardiovascular and Respiratory Center 1696 Itai, Kumagaya, Saitama 360-0105 (Japan) Tel. +81 48 536 9900, Fax +81 48 536 9920, E-Mail takayanagi.noboru @ pref.saitama.jp © 2010 S. Karger AG, Basel 0025–7931/10/0802–0098$26.00/0 Accessible online at: www.karger.com/res For editorial comment see p. 96 D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /4 /2 01 7 6: 07 :1 9 P M