A 16-Year Prospective Study of Community-Onset Bacteremic Acinetobacter Pneumonia

Low mortality with appropriate initial empirical antibiotic protocols

Joshua Davis, Mark McMillan, Ashwin Swaminathan, John Kelly, Kim Piera, Robert Baird, Bart Currie, Nicholas Anstey

Research output: Contribution to journalArticleResearchpeer-review

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 ceft riaxone. 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.
Original languageEnglish
Pages (from-to)1038-1045
Number of pages8
JournalChest
Volume146
Issue number4
DOIs
Publication statusPublished - 2014

Fingerprint

Acinetobacter
Pneumonia
Prospective Studies
Anti-Bacterial Agents
Mortality
meropenem
Alcohols
Acinetobacter baumannii
Ciprofloxacin
Clinical Protocols
Cross Infection
Hospital Mortality
Gentamicins
Tertiary Care Centers
Observational Studies
Demography

Cite this

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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 ceft riaxone. 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.",
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author = "Joshua Davis and Mark McMillan and Ashwin Swaminathan and John Kelly and Kim Piera and Robert Baird and Bart Currie and Nicholas Anstey",
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language = "English",
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A 16-Year Prospective Study of Community-Onset Bacteremic Acinetobacter Pneumonia : Low mortality with appropriate initial empirical antibiotic protocols. / Davis, Joshua; McMillan, Mark; Swaminathan, Ashwin; Kelly, John; Piera, Kim; Baird, Robert; Currie, Bart; Anstey, Nicholas.

In: Chest, Vol. 146, No. 4, 2014, p. 1038-1045.

Research output: Contribution to journalArticleResearchpeer-review

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T1 - A 16-Year Prospective Study of Community-Onset Bacteremic Acinetobacter Pneumonia

T2 - Low mortality with appropriate initial empirical antibiotic protocols

AU - Davis, Joshua

AU - McMillan, Mark

AU - Swaminathan, Ashwin

AU - Kelly, John

AU - Piera, Kim

AU - Baird, Robert

AU - Currie, Bart

AU - Anstey, Nicholas

PY - 2014

Y1 - 2014

N2 - 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 ceft riaxone. 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.

AB - 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 ceft riaxone. 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.

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