Look-back investigation of a health care worker infected with human immunodeficiency virus.

We report the referral of an HIV-infected surgeon and a subsequent first-ever recommended look-back investigation in Hong Kong. Efficient coordination and effective implementation of the look-back investigation yielded a high response rate of 92.3% of priority patients, with none tested HIV positive. Our experience reconfirmed the very small risk of provider-to-patient HIV transmission and the crucial importance of infection control.