Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in paediatric wards: a nested case-control study.
OBJECTIVE
A high rate (48.6%) of extended spectrum beta-lactamase production among Klebsiella pneumoniae (ESBL-KP) clinical isolates in the paediatric wards of our hospital prompted the introduction of enhanced infection control measures, and after the implementation of these measures, we instituted a prospective surveillance programme, with a nested case-control study to determine the risk factors for rectal colonisation by ESBL-KP.


METHODS
Over a 1-year period, rectal swabs from patients and samples from the environment and the hands of health-care workers were cultured. Strain typing of ESBL-KP isolates was performed using pulsed-field gel electrophoresis. Characteristics of patients who were colonised with ESBL-KP during hospital stay were compared with those of patients who remained negative for ESBL-KP. Multivariate analysis was performed with model-building using stepwise logistic regression to determine independent risk factors for ESBL-KP acquisition.


RESULTS
Forty (18.5%) of 216 patients became colonised with ESBL-KP. The strongest independent predictors of ESBL-KP colonisation were mechanical ventilation (odds ratio (OR): 4.28) and hospitalisation for longer than 14 days (OR: 6.97). Genotyping of the isolates indicated probable patient-to-patient transmission; however, we could not determine the route of this spread. During the study period, a 1.6% rate of ESBL-KP clinical infection per 500 patient admissions was observed, in contrast to a 7% rate in the previous year.


CONCLUSIONS
Prolonged length of stay and mechanical ventilation were independent predictors of ESBL-KP colonisation. Enhanced infection control measures, antimicrobial stewardship and screening for rectal carriage were associated with a substantial decrease in paediatric units.
Department of Clinical Microbiology, Marmara University School of Medicine, Istanbul, Turkey.
Serap
S
Demir
Ahmet
A
Soysal
Mustafa
M
Bakir
Mary E
ME
Kaufmann
Aysegul
A
Yagci
D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D004866:Equipment Contamination; D005260:Female; D006745:Hospital Bed Capacity, 300 to 499; D006784:Hospitals, Teaching; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D007902:Length of Stay; D008297:Male; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D011446:Prospective Studies; D012121:Respiration, Artificial; D012307:Risk Factors; D014421:Turkey / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis*
D001618:beta-Lactamases