Outbreak of infection with a multiresistant Klebsiella pneumoniae strain associated with contaminated roll boards in operating rooms

Abstract

An outbreak with a multiresistant Klebsiella pneumoniae (MRKP) strain among seven patients admitted to the adult intensive care unit (ICU) of a regional teaching hospital in The Netherlands was investigated. Epidemiologic investigations revealed a short delay between an operation and the acquisition of the MRKP strain. A case-control study comprising 7 cases and 14 controls was conducted to identify the risk factors associated with the acquisition of the MRKP strain. An operation at each of two operation rooms was strongly associated with the acquisition of the MRKP strain: odds ratio of 36 (95% confidence interval, 2.7 to 481.2; P=0.003, Fisher exact two-tailed test). Cultures of environmental specimens of the operation rooms revealed contamination of the roll boards used to transport patients from the bed to the operation table with the MRKP strains. Molecular genotyping of the isolates revealed clonal similarity between the isolates of the seven cases, isolates from environmental specimen cultures, and in addition, an MRKP isolate from a re-patriated ICU patient from earlier that year. The outbreak ended after cleaning and replacement of the roll boards in the operation rooms and implementation of additional barrier precautions for colonized or infected patients. It was concluded that two operation rooms played a significant role in the transmission of an MRKP strain between ICU patients during the presented outbreak.

FIG. 1.

Course of the outbreak presented in time. The shading of the bars is explained by the legend at the bottom of the figure.

FIG. 2.

Contaminated roll boards used to transport patients from their bed to the operation table and vice versa. Note the broken areas and the small ball bearings present (arrows).

FIG. 3.

Dendrogram of genotyping results. A to G represent the ME-AFLP patterns of the MRKP strains cultured from cases 1 to 7 and the index patient presented in Table 1, respectively; OR-A and OR-B represent the patterns of the MRKP strains isolated from the roll boards in OR-X and OR-Y, respectively; R1 to R5, MRKP strains isolated earlier in 2000 (R1 to R4) or isolated beginning in 2001 (R5); C1 to C3, controls that represent Klebsiella pneumoniae isolates with a common antibiotic susceptibility pattern.