Prevalence of antibody to human immunodeficiency virus and hepatitis B surface antigen in blood samples submitted to a hospital laboratory. Implications for handling specimens.

The prevalence of hepatitis B surface antigen (HBsAg) and antibody to human immunodeficiency virus (HIV) was determined in serum or plasma specimens of 506 patients submitted to the clinical chemistry laboratory of an urban teaching hospital, and the results were correlated with "biohazard" warning labels on the specimens. Hepatitis B surface antigen, HIV antibody, or either of these were present in 32 (6.3%), 15 (3.0%), and 44 specimens (8.7%), respectively. Ten (67%) of 15 specimens with HIV antibody and nine (28%) of 32 with HBsAg bore biohazard labels. Among 473 unlabeled specimens, HIV antibody was present in five (1.1%), HBsAg was present in 23 (4.9%), and 27 (5.7%) contained either or both of these markers. All clinical and laboratory personnel should be vaccinated against hepatitis B and should handle all blood specimens as if they were infected, regardless of biohazard labeling. By fostering complacency in handling unlabeled specimens, the use of biohazard labels may paradoxically increase the risk that health care workers will be exposed to HIV and hepatitis B virus.