title: Overall burden of healthcare-associated infections among surgical patients. Results of a national study.
abstract: OBJECTIVE
  To assess the overall burden of healthcare-associated infections (HAIs) in patients exposed and nonexposed to surgery.
  
  
  BACKGROUND
  Targeted HAI surveillance is common in healthcare institutions, but may underestimate the overall burden of disease.
  
  
  METHODS
  Prevalence study among patients hospitalized in 50 acute care hospitals participating in the Swiss Nosocomial Infection Prevalence surveillance program.
  
  
  RESULTS
  Of 8273 patients, 3377 (40.8%) had recent surgery. Overall, HAI was present in 358 (10.6%) patients exposed to surgery, but only in 206 (4.2%) of 4896 nonexposed (P < 0.001). Prevalence of surgical site infection (SSI) was 5.4%. Healthcare-associated infections prevalence excluding SSI was 6.5% in patients with surgery and 4.7% in those without (P < 0.0001). Patients exposed to surgery carried less intrinsic risk factors for infection (age >60 years, 55.6% vs 63.0%; American Society of Anesthesiologists score >3,5.9% vs 9.3%; McCabe for rapidly fatal disease, 3.9% vs 6.6%; Charlson comorbidity index >2, 12.3% vs 20.9%, respectively; all P < 0.001) than those nonexposed, but more extrinsic risk factors (urinary catheters, 39.6%vs 14.1%; central venous catheters, 17.8% vs 7.1%; mechanical ventilation, 4.7% vs 1.3%; intensive care stay, 18.3% vs 8.8%, respectively; all P<0.001). Exposure to surgery independently predicted an increased risk of HAI (odds ratio 2.43; 95% CI 2.0–3.0).
  
  
  CONCLUSIONS
  Despite a lower intrinsic risk, patients exposed to surgery carried more than twice the overall HAI burden than those nonexposed; almost half was accountable to SSI. Extending infection control efforts beyond SSI prevention in these patients might be rewarding, especially because of the extrinsic nature of risk factors.
authors.affiliation: Infection Control Program, University of Geneva Hospitals and Faculty of Medicine, Rue Gabrielle Perret-Gentil 4, Geneva 14, Switzerland. hugo.sax@hcuge.ch
authors.forename: Hugo
authors.initials: H
authors.lastname: Sax
authors.forename: Ilker
authors.initials: I
authors.lastname: Uçkay
authors.forename: Carlo
authors.initials: C
authors.lastname: Balmelli
authors.forename: Enos
authors.initials: E
authors.lastname: Bernasconi
authors.forename: Karim
authors.initials: K
authors.lastname: Boubaker
authors.forename: Kathrin
authors.initials: K
authors.lastname: Mühlemann
authors.forename: Christian
authors.initials: C
authors.lastname: Ruef
authors.forename: Nicolas
authors.initials: N
authors.lastname: Troillet
authors.forename: Andreas
authors.initials: A
authors.lastname: Widmer
authors.forename: Giorgio
authors.initials: G
authors.lastname: Zanetti
authors.forename: Didier
authors.initials: D
authors.lastname: Pittet
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006757:Hospital Units; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013530:Surgical Wound Infection / Q000453:epidemiology* / Q000382:microbiology; D013557:Switzerland / Q000453:epidemiology