Risk factors for KPC-producing Klebsiella pneumoniae enteric colonization upon ICU admission

Abstract

Objectives: To identify risk factors for KPC-producing Klebsiella pneumoniae (KPC-Kp) enteric colonization at intensive care unit (ICU) admission. Recently, the emergence and spread of KPC-producing Enterobacteriaceae in healthcare facilities has become an important issue. Understanding the extent of the reservoir in ICUs may be important for targeted intervention.

Methods: A prospective observational study of all patients (n = 405) admitted to an ICU was conducted during a 22 month period. Rectal samples were taken from each patient within 12-48 h of admission and were inoculated in selective chromogenic agar. K. pneumoniae isolates were characterized by standard methodology. Antibiotic susceptibility testing (agar disc diffusion method), MIC determination (Etest), identification of carbapenemase-producing isolates (Hodge test) and determination of KPC production (boronic acid-imipenem disc test) were performed. The presence of the bla(KPC) gene was confirmed by PCR. Epidemiological data were collected from the ICU computerized database and patient chart reviews.

Results: Upon ICU admission, 52/405 (12.8%) patients were colonized with KPC-Kp that was associated with the following risk factors: previous ICU stay (OR 12.5; 95% CI 1.8-86.8), chronic obstructive pulmonary disease (OR 6.3; 95% CI 1.2-31.9), duration of previous hospitalization (OR 1.3; 95% CI 1.1-1.4), previous use of carbapenems (OR 5.2; 95% CI 1.0-26.2) and previous use of β-lactams/β-lactamase inhibitors (OR 6.7; 95% CI 1.4-32.9). For patients previously hospitalized on peripheral wards the following risk factors were identified: duration of hospitalization prior to ICU admission (OR 1.1; 95% CI 1.1-1.3), number of comorbidities (OR 1.9; 95% CI 1.1-3.5) and number of antimicrobials administered (OR 2.1; 95% CI 1.3-3.3).

Conclusions: The high prevalence of KPC-Kp enteric carriage in ICU patients at admission dictates the importance of implementation of infection control measures and strict antibiotic policies prior to ICU transfer.