[1] Univ Pittsburgh, Med Ctr, Div Hosp Epidemiol & Infect Control, Pittsburgh, PA 15213 USA
[2] Univ Pittsburgh, Sch Med, Infect Dis Epidemiol Res Unit, Pittsburgh, PA USA
[3] Univ Pittsburgh, Grad Sch Publ Hlth, Pittsburgh, PA USA
[4] Ctr Dis Control & Prevent, Div Healthcare Qual Promot, Atlanta, GA USA
[5] Hosp Nantes, Nantes, France
[6] Virginia Commonwealth Univ, Richmond, VA USA
[7] Ctr Dis Control & Prevent, Natl Ctr Infect Dis, Atlanta, GA USA
[8] Yale Univ, Hosp St Raphael, Div Hosp Epidemiol, New Haven, CT USA
[9] Univ Virginia, Hlth Syst, Charlottesville, VA USA