title: A 16-year prospective study of community-onset bacteremic Acinetobacter pneumonia: low mortality with appropriate initial empirical antibiotic protocols.
abstract: BACKGROUND
  The genus Acinetobacter, well known as a nosocomial pathogen, can also cause severe community-onset pneumonia. Previous small case series have suggested fulminant disease and a pooled hospital mortality of > 60%.
  
  
  METHODS
  We conducted a prospective observational study of all episodes of bacteremic, community-onset, and radiologically confirmed pneumonia due to Acinetobacter species at a tertiary referral hospital in tropical Australia from 1997 to 2012 following the introduction of routine empirical treatment protocols covering Acinetobacter. Demographic, clinical, microbiologic, and outcome data were collected.
  
  
  RESULTS
  There were 41 episodes of bacteremic community-onset Acinetobacter pneumonia, of which 36 had no indicators suggesting health-care-associated infection. Of these, 38 (93%) were Indigenous Australians, one-half were men, the average age was 44.1 years, and 36 episodes (88%) occurred during the rainy season. All patients had at least one risk factor, with hazardous alcohol intake in 82%. Of the 37 isolates available for molecular speciation, 35 were Acinetobacter baumannii and two were Acinetobacter nosocomialis. All isolates were susceptible in vitro to gentamicin, meropenem, and ciprofloxacin, but only one was fully susceptible to ceftriaxone. ICU admission was required in 80%. All 41 patients received appropriate antibiotics within the first 24 h of admission, and 28- and 90-day mortality were both low at 11%.
  
  
  CONCLUSIONS
  Community-acquired Acinetobacter pneumonia is a severe disease, with the majority of patients requiring ICU admission. Most patients have risk factors, particularly hazardous alcohol use. Despite this severity, correct initial empirical antibiotic therapy in all patients was associated with low mortality.
authors.affiliation: The Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University; Department of Infectious Diseases, Royal Darwin Hospital, Darwin, NT, Australia. Electronic address: joshua.davis@menzies.edu.au.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Davis
authors.affiliation: The Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University.
authors.forename: Mark
authors.initials: M
authors.lastname: McMillan
authors.affiliation: Department of Infectious Diseases, Royal Darwin Hospital, Darwin, NT, Australia; Department of Microbiology, Royal Darwin Hospital, Darwin, NT, Australia.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Swaminathan
authors.affiliation: Department of Infectious Diseases, Royal Darwin Hospital, Darwin, NT, Australia; Department of Microbiology, Royal Darwin Hospital, Darwin, NT, Australia.
authors.forename: John A
authors.initials: JA
authors.lastname: Kelly
authors.affiliation: The Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University.
authors.forename: Kim E
authors.initials: KE
authors.lastname: Piera
authors.affiliation: Department of Infectious Diseases, Royal Darwin Hospital, Darwin, NT, Australia; Department of Microbiology, Royal Darwin Hospital, Darwin, NT, Australia.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Baird
authors.affiliation: The Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University; Department of Infectious Diseases, Royal Darwin Hospital, Darwin, NT, Australia.
authors.forename: Bart J
authors.initials: BJ
authors.lastname: Currie
authors.affiliation: The Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University; Department of Infectious Diseases, Royal Darwin Hospital, Darwin, NT, Australia.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Anstey
mesh_terms: D000150:Acinetobacter / Q000187:drug effects*; D000151:Acinetobacter Infections / Q000188:drug therapy / Q000401:mortality*; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001315:Australia; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D017714:Community-Acquired Infections; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D011446:Prospective Studies
chemical_list: D000900:Anti-Bacterial Agents