 Exclusion Criteria: Patients will be excluded form the study if: 1 they are unable or unwilling to give informed consent; 2 the patient is less than 18 years of age; 3 there is evidence of pre-existing infection at or adjacent to the operative site; 4 a break in sterile technique occurs; 5 the patient has a history of allergy to chlorhexidine, alcohol or iodophors. 