title: Clinical characteristics of Q fever and etiology of community-acquired pneumonia in a tropical region of southern Taiwan: a prospective observational study.
abstract: BACKGROUND
  The clinical characteristics of Q fever are poorly identified in the tropics. Fever with pneumonia or hepatitis are the dominant presentations of acute Q fever, which exhibits geographic variability. In southern Taiwan, which is located in a tropical region, the role of Q fever in community-acquired pneumonia (CAP) has never been investigated.
  
  
  RESULTS
  During the study period, May 2012 to April 2013, 166 cases of adult CAP and 15 cases of acute Q fever were prospectively investigated. Cultures of clinical specimens, urine antigen tests for Streptococcus pneumoniae and Legionella pneumophila, and paired serologic assessments for Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Q fever (Coxiella burnetii) were used for identifying pathogens associated with CAP. From April 2004 to April 2013 (the pre-study period), 122 cases of acute Q fever were also included retrospectively for analysis. The geographic distribution of Q fever and CAP cases was similar. Q fever cases were identified in warmer seasons and younger ages than CAP. Based on multivariate analysis, male gender, chills, thrombocytopenia, and elevated liver enzymes were independent characteristics associated with Q fever. In patients with Q fever, 95% and 13.5% of cases presented with hepatitis and pneumonia, respectively. Twelve (7.2%) cases of CAP were seropositive for C. burnetii antibodies, but none of them had acute Q fever. Among CAP cases, 22.9% had a CURB-65 score ≧2, and 45.8% had identifiable pathogens. Haemophilus parainfluenzae (14.5%), S. pneumoniae (6.6%), Pseudomonas aeruginosa (4.8%), and Klebsiella pneumoniae (3.0%) were the most common pathogens identified by cultures or urine antigen tests. Moreover, M. pneumoniae, C. pneumoniae, and co-infection with 2 pathogens accounted for 9.0%, 7.8%, and 1.8%, respectively.
  
  
  CONCLUSIONS
  In southern Taiwan, Q fever is an endemic disease with hepatitis as the major presentation and is not a common etiology of CAP.
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Division of Infectious Diseases, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung City, Taiwan; Division of Infection Control Laboratory, E-Da Hospital/I-Shou University, Kaohsiung City, Taiwan.
authors.forename: Chung-Hsu
authors.initials: CH
authors.lastname: Lai
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Faculty of Medicine, Department of Microbiology, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.
authors.forename: Lin-Li
authors.initials: LL
authors.lastname: Chang
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Division of Infectious Diseases, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung City, Taiwan.
authors.forename: Jiun-Nong
authors.initials: JN
authors.lastname: Lin
authors.affiliation: Division of Infection Control Laboratory, E-Da Hospital/I-Shou University, Kaohsiung City, Taiwan.
authors.forename: Wei-Fang
authors.initials: WF
authors.lastname: Chen
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung County, Taiwan.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Wei
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung County, Taiwan.
authors.forename: Chien-Tung
authors.initials: CT
authors.lastname: Chiu
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung County, Taiwan.
authors.forename: Jiun-Ting
authors.initials: JT
authors.lastname: Wu
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung County, Taiwan.
authors.forename: Chi-Kuei
authors.initials: CK
authors.lastname: Hsu
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung County, Taiwan.
authors.forename: Jung-Yueh
authors.initials: JY
authors.lastname: Chen
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung County, Taiwan.
authors.forename: Ho-Sheng
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung City, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei City, Taiwan.
authors.forename: Hsi-Hsun
authors.initials: HH
authors.lastname: Lin
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung City, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.
authors.forename: Yen-Hsu
authors.initials: YH
authors.lastname: Chen
mesh_terms: D000328:Adult; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology*; D011446:Prospective Studies; D011778:Q Fever / Q000453:epidemiology* / Q000209:etiology*; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology