Risk-factors for acquisition of extended-spectrum β-lactamase-producing Escherichia coli among hospitalised patients

Abstract

Between 1996 and 2002, 103 hospitalised patients yielding one or more clinical isolates of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) were identified. A significant increase was observed in the incidence of ESBL-EC colonisation or infection during the study period (1.65 episodes/100 000 patient-days in 1996 to 12.6 episodes/100 000 patient-days in 2002; p 0.01). Infection developed in 70 (68%) patients (75 episodes), with surgical site (44%) and urinary tract (17%) infections being the most frequent. Pulsed-field gel electrophoresis showed extensive clonal diversity among the isolates. A case-control study and multivariate analysis identified female gender (OR 2.1; p 0.01), use of a nasogastric tube (OR 3.5; p 0.001) and previous antibiotic therapy (OR 3.9; p < 0.001) as independent variables associated with acquisition of ESBL-EC. The study demonstrated a progressive increase in the number of ESBL-EC isolates in a non-epidemic setting. Most cases of ESBL-EC colonisation or infection occurred in hospitalised patients exposed to invasive procedures and antibiotic pressure.

Multivariate analysis of risk factors for ESBL and AmpC producing Escherichia coli and Klebsiella pneumoniae at a Tertiary Care Hospital in Karnataka: A case control study

“…This is in accordance with the studies conducted by Pena C et al, 1 Demirdag K et al 14 and Ozgunes I et al 13 who reported surgical intervention as a risk factor. The importance of this factor relates to different epidemiological aspects, such as the effectiveness of infection control measures at the hospital.…”

“…Prior treatment with antibiotics was identified as a significant risk factor for infection with ESBL producing strains in different studies done by Santhi M et al [5] , Pena C et al, 1 Baral P et al, 3 Ozgunes I et al 13 and Tumbarello M et al 9 It was correlating with our present study. Similarly longer duration of hospital stay was identified as independent risk factor in various studies conducted by Santhi M et al, 5 Baral P et al 3 and Tumbarello M et al 9 Furthermore, Foley's catheter, intravenous catheter, central venous catheter, intubation, surgery and mechanical ventilation were identified as risk factors associated with ESBL production by the study done by Ozgunes I et al 13 which correlated with our study.…”

“…A study conducted by M Shanthi and Uma Sekar 5 at Chennai, India concluded that prior exposure to multiple antibiotics especially beta lactam antibiotics was an important contributing factor in acquisition of ESBL producing infections. Pena C et al 1 in their study at Spain found previous antibiotic therapy (OR=3.9, p< 0.001) as one of the independent variables associated with ESBL producing organisms.…”

“…10 Numerous studies have used a case-control design with which to assess risk factors for colonization and infection with ESBL/AmpC-producing organisms. 5,1,14,13,16 Analysis of the results of these studies yields a plethora of conflicting results, likely due to differences in study populations, selection of cases, selection of controls and sample size. We need a multivariate analysis in view of multiple variables.…”

“…1 In many parts of the world, 10-40% of strains of Escherichia coli and Klebsiella pneumoniae express ESBLs. 2 High rates of AmpC β-lactamase (ABL) producing Enterobacteriaceae have been reported-36.5% in India, 35.6% in Pakistan and 26.2% in China.…”