A patient contact model was devised for health care workers (HCWs) to define heavy hand contamination with aerobic gram-negative bacilli (AGNB) that requires alcohol for complete removal. In patients, AGNB quantitation was per ml cup scrub fluid; in HCWs per ml glove juice. Following 15-second contact, two Proteeae groin carriers yielding greater than or equal to 4 log10 AGNB (high burden) transmitted greater than or equal to 3 log10 in 67% of 24 tests of six HCWs, and less than or equal to 2 log10 in 29%. Two carriers yielding less than or equal to 3 log10 in 38%. At less than or equal to 2 log10 HCW acquisitions, soap eliminated all AGNB in three of 10; alcohol in eight of eight (p = 0.009). Contact with densely colonized patient skin may cause heavy AGNB contamination of HCWs' hands that generally necessitates alcohol for complete removal.