The Centers for Disease Control and Prevention has updated its guidelines for cleaning, disinfecting and sterilizing medical devices and the health care environment. New topics include inactivating antibiotic-resistant bacteria and disinfecting complex medical instruments such as endoscopes. The guide also incorporates several changes advocated by AHA, including the need to address equipment design, emerging pathogens and bioterrorist agents, and provide consistent guidelines for diluting bleach. The guidelines were last updated in 1985.