Human immunodeficiency virus transmission in health care settings: risk and risk reduction.

Surveillance data and case reports document that health care workers (HCWs) risk occupationally acquired human immunodeficiency virus (HIV) infection. Transmission of HIV to patients of an infected HCW during invasive procedures has also been reported. The risk to a susceptible HCW depends on the prevalence of HIV infection among patients, the nature and frequency of occupational blood exposures, and the risk of transmission per exposure. Blood exposure rates vary by occupation, by procedure, and by compliance with preventive measures. Future efforts to protect both HCWs and patients must include improved surveillance, risk assessment, study of postexposure prophylaxis, and an emphasis on exposure prevention, including development of safer medical devices, work practices, and personal protective equipment that are acceptable to HCWs and do not adversely affect patient care.