Surveillance of Health Care Workers Exposed to Blood from Patients Infected with the Human Immunodeficiency Virus

Since 1983, we have conducted national surveillance of health care workers exposed to blood or body fluids from persons infected with the human immunodeficiency virus (HIV), to assess the risk of HIV transmission by such exposures. As of July 31, 1988, 1201 health care workers with blood exposures had been examined, including 751 nurses (63 percent), 164 physicians and medical students (14 percent), 134 laboratory workers (11 percent), and 90 phlebotomists (7 percent). The exposures resulted from needle-stick injuries (80 percent), cuts with sharp objects (8 percent), open-wound contamination (7 percent), and mucous-membrane exposure (5 percent). We concluded that 37 percent of the exposures might have been prevented. Of 963 health care workers whose serum has been tested for HIV antibody at least 180 days after exposure, 4 were positive, yielding a seroprevalence rate of 0.42 percent (upper limit of 95 percent confidence interval, 0.95 percent). Three subjects experienced an acute retroviral syndrome associated with documented seroconversion; serum collected within 30 days of exposure was not available from the fourth person. Two exposures that resulted in seroconversion were caused by coworkers during resuscitation procedures. We conclude that the risk of HIV infection after exposure to the blood of a patient infected with HIV is low, but at least six months of follow-up is recommended. Many exposures can be prevented by careful adherence to existing infection-control precautions, even during emergencies.