title: Invasive Systemic Infection After Hospital Treatment for Diabetic Foot Ulcer: Risk of Occurrence and Effect on Survival.
abstract: BACKGROUND
  Diabetic foot ulcers (DFUs) threaten limbs and prompt hospitalization. After hospitalization, remote-site invasive systemic infection related to DFU (DFU-ISI) may occur. The characteristics of DFU-ISIs and their effect on mortality risk have not been defined.
  
  
  METHODS
  We conducted a retrospective cohort study of 819 diabetic patients hospitalized for treatment of 1212 unique DFUs during a 9-year period. We defined the index ulcer as that present at the first (index) DFU admission to our hospital. We defined DFU-ISI as a nonfoot infection that occurred after the index hospitalization and was caused by a microorganism concomitantly or previously cultured from the index ulcer. We determined the frequency, risk factors, and mortality risk associated with DFU-ISIs.
  
  
  RESULTS
  After 1212 index DFU hospitalizations, 141 patients had 172 DFU-ISIs. Of the initial 141 DFU-ISIs, 64% were bacteremia, 13% deep abscesses, 10% pneumonia, 7% endocarditis, and 6% skeletal infections. Methicillin-resistant Staphylococcus aureus (MRSA) caused 57% of the ISIs. Patients with initial DFU cultures yielding MRSA and protracted open ulcers had a high 24-month cumulative probability of DFU-ISI (31%) and all-cause mortality rate (13%). Analysis with Cox regression modeling showed that complicated ulcer healing (hazard ratio, 3.812; 95% confidence interval, 2.434-5.971) and initial DFU culture yielding MRSA (2.030; 1.452-2.838) predicted DFU-ISIs and that DFU-ISIs were associated with increased mortality risk (1.987; 1.106-3.568).
  
  
  CONCLUSIONS
  DFU-ISIs are important late complications of DFUs. Prevention of DFU-ISIs should be studied prospectively. Meanwhile, clinicians should aggressively incorporate treatment to accelerate ulcer healing and address MRSA into the care of diabetic patients with foot ulcers.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, and.|Department of Emergency Medicine, National Taiwan University Hospital, College of Medicine, Taipei.
authors.forename: Shey-Ying
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Division of Podiatry, Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.
authors.forename: John M
authors.initials: JM
authors.lastname: Giurini
authors.affiliation: Division of Infectious Diseases, Department of Medicine, and akarchme@bidmc.harvard.edu.
authors.forename: Adolf W
authors.initials: AW
authors.lastname: Karchmer
mesh_terms: D000038:Abscess / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D000368:Aged; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D001850:Bone Diseases, Infectious / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D015331:Cohort Studies; D017719:Diabetic Foot / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality*; D004697:Endocarditis, Bacterial / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013203:Staphylococcal Infections / Q000150:complications / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality*
keywords: diabetes mellitus; foot ulcer; methicillin resistant Staphylococcus aureus
  ; mortality.; systemic infection