Where the wild things are

Carbapenem-resistant Enterobacteriaceae (CRE) are a major threat to public health worldwide and Israel is among the countries with the highest rates of these pathogens. A concerted campaign has done a good job of bringing the national outbreak under control, but problems persist1. An Israeli hospital investigated the extent of environmental contamination with CRE in the vicinity of 34 CRE-carriers using two different sampling methods; contact plates and swabs (with or without enrichment). Pilot sampling was performed to identify the five sites that were most likely to be contaminated (pillow, crotch and leg area on the bed, personal bedside table and infusion pump). To investigate the effect of cleaning on the recovery of CRE, the five sites were sampled at two different times; 4 and 24 hr after rooms were cleaned and patient cloths and sheets were changed.


The study detected CRE in the surrounding environment of most (88%) of the patients sampled, showing that a high proportion of carriers shed these pathogens into their environment which can then be transmitted. Recovery was highest in the carrier’s immediate environment with the patient bed being the most contaminated. Not surprisingly, recovery of CRE from the environment was reduced when sampling was done 4 hr after cleaning compared to 24 hr after cleaning (21% of sites contaminated vs 27%). However these results also highlight the speed by which the patient environment is re-contaminated with CRE after cleaning. The study also showed that the choice of the detection method is also important and reported that contact plates were more efficient at recovering CRE than swabs even with enrichment broth.

The high rate of recovery of CRE from the environment in this study is surprising. Hence, hospitals with CRE-carriers should expect the environment in the vicinity of these patients to be contaminated. Regular and thorough cleaning of the patient environment and equipment should be an integral part of the hospital’s infection control strategy to reduce the spread of these pathogens.

Article citation:

Lerner A, Adler A, Abu-Hanna Jet al.Environmental contaminationby carbapenem-resistantenterobacteriaceae. J Clin Microbiol 2013;51:177-81.


1.       Schwaber MJ, Lev B, Israeli Aet al. Containment of a country-wide outbreak of carbapenem-resistant Klebsiella pneumoniae in Israeli hospitals via a nationally implemented intervention. Clin Infect Dis 2011; 52: 848-855.

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