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

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.

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.

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).

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.