About the Authors
Infection Control Program, University of Geneva Hospitals and Medical School, Geneva, Switzerland
Veterans Affairs Salt Lake City Health Care System, Division of Epidemiology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
The authors have declared that no competing interests exist.
Wrote the first draft of the manuscript: SH. Contributed to the writing of the manuscript: MS. ICMJE criteria for authorship read and met: SH MS. Agree with manuscript results and conclusions: SH MS.