title: Clinical features and prognostic factors of anaerobic infections: a 7-year retrospective study.
abstract: OBJECTIVE
  Risk factors for mortality resulting from anaerobic infection are incompletely defined. The clinical significance of a broad range of pathogenic obligate anaerobic organisms was examined, and factors independently associated with mortality were identified in patients with clinically significant anaerobic infections.
  
  
  METHODS
  The medical records of 1,050 patients with anaerobic infections were retrospectively reviewed at Severance Hospital in Seoul, Korea.
  
  
  RESULTS
  The mean age of the patients was 54.1+/-16.8 years, and 57.7% were men. Overall, 320 (30.5%) patients with case-defined illness experienced pain at the affected site, and 230 (21.9%) experienced pus flow from lesions. Ten (1.4%) patients presented with shock, and 80.3% of the clinically significant cases were polymicrobial anaerobic infections. The mean number of pathogens, including aerobic and anaerobic bacteria, was 3.7+/-1.0 (minimum 1, maximum 5), and the number of anaerobic organisms was 1.0+/-0.3 in each specimen. The major pathogens by rank were the Bacteroides fragilis group, which accounted for 41.8% of anaerobic infections, followed by Clostridium spp. (11.8%), Prevotella spp. (9.4%), and Peptostreptococcus spp. (8.4%). Escherichia coli (17.5%), Staphylococcus aureus (7.5%), and Klebsiella pneumoniae (7.5%) were common concomitant aerobic organisms. The overall crude mortality rate resulting from anaerobic infection was 29.7%. Among the determining factors associated with mortality, liver disease (p=0.003) and old age (p=0.005) were significant in multivariate analysis.
  
  
  CONCLUSIONS
  Anaerobic infection is polymicrobial and has a significant role in morbidity and mortality. Underlying liver disease was associated with poor prognosis in anaerobic infection.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yoonseon
authors.initials: Y
authors.lastname: Park
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Dongeun
authors.initials: D
authors.lastname: Yong
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
authors.forename: June Myung
authors.initials: JM
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001421:Bacteria, Anaerobic / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology / Q000628:therapy; D004322:Drainage / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents