The nurse clarifies that the difference between the use of earlier types of isolation procedures and the use of current Standard Procedures plus Transmission-Based Precautions as outlined by the CDC:

Is complicated and hard to follow.

Is that new diseases have continued to appear for which the older isolation techniques were ineffective.

Is based on newer knowledge of how HIV is spread, to better protect health care workers from blood-borne pathogens.

Is based on the premise in the new procedures that all body substances except sweat may be infectious, even when the person is not known to have a specific disease.