Because it is often impossible to know what isolates or specimens might be infectious, all patient and
laboratory specimens are treated as infectious and handled according to “standard precautions.” Standard
precautions are guidelines that combine the major features of “universal precautions and body substance
isolation” practices. Standard precautions cover the transmission of all known infectious agents and thus
Number 1 M02-A11
© 2 Clinical and Laboratory Standards Institute. All rights reserved.
are more comprehensive than universal precautions, which are intended to apply only to transmission of
blood-borne pathogens. Standard and universal precaution guidelines are available from the Centers for
Disease Control and Prevention (CDC).11 For specific precautions for preventing the laboratory
transmission of all known infectious agents from laboratory instruments and materials and for
recommendations for the management of exposure to all known infectious diseases, refer to CLSI
document M29.