RT Journal Article SR Electronic T1 Clostridium difficile infection in hospitals: risk factors and responses JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 45 OP 46 DO 10.1503/cmaj.1040966 VO 171 IS 1 A1 Thomas J. Louie A1 Jon Meddings YR 2004 UL http://www.cmaj.ca/content/171/1/45.abstract