Prevalence of human immunodeficiency virus and hepatitis B virus in unselected hospital admissions: implications for mandatory testing and universal precautions.

The prevalence of human immunodeficiency virus (HIV) and hepatitis B virus in serial unselected hospital admissions was determined to examine the potential efficacy of a system of universal blood and body fluid precautions versus a system based on selected or unselected screening. Serum was obtained from 616 (97%) of the 636 patients admitted during a 1-month period and interviews were completed on 540. Of the 616, 23 (3.7%) were confirmed positive for HIV, and 12 (2.0%) of 612 for hepatitis B surface antigen. Of 33 infected persons, only 8 were known to be positive on admission and only 22 were in "high-risk" groups; therefore, selective precautions would not have been effective. Mandatory testing would have required 1216 tests to identify 25 infected persons and would leave in doubt the presence of other transmissible diseases. On the basis of these data, it appears that universal precautions are a logical system of infection control.