Unified procedures to control those infections that are transmitted by inoculation of blood are recommended. These should be applied to patients with acquired immune-deficiency syndrome (AIDS), AIDS-related complex, persistent generalized lymphadenopathy or hepatitis B, those with serological evidence of infection by human immunodeficiency virus or hepatitis B virus, and those in medical and social categories with a higher than average prevalence of such infections. When the identification of these categories of patient would be particularly difficult, the precautions should be applied to all patients, in situations of high risk for inoculation incidents. Rational infection-control measures, based on the known mode of spread, permit efficient management of infected patients, with satisfactory protection of staff and other patients.