Epidemiological study of hospital-acquired infection with vancomycin-resistant Enterococcus faecium: possible transmission by an electronic ear-probe thermometer.

Clonal spread of vancomycin-resistant Enterococcus faecium among seven patients on one ward of a community teaching hospital was identified by contour-clamped homogeneous electric-field gel electrophoresis. Environmental cultures isolated the same strain from the handle of a shared electronic ear-probe thermometer. Cross-contamination of the clonal strain between two geographically separate units on this ward, sharing equipment but not personnel, suggests the possibility of an environmental source.