#Chapter 16 blood borne parhogens and principles of asepsis update
#Chapter 16 blood borne parhogens and principles of asepsis manual

#Chapter 16 blood borne parhogens and principles of asepsis manual

The germicides differ markedly among themselves primarily in their antimicrobial spectrum and rapidity of action.Ĭleaning, on the other hand, is the removal of visible soil (e.g., organic and inorganic material) from objects and surfaces, and it normally is accomplished by manual or mechanical means using water with detergents or enzymatic products.

Low-level disinfectants may kill most vegetative bacteria, some fungi, and some viruses in a practical period of time (≤10 minutes), whereas intermediate-level disinfectants may be cidal for mycobacteria, vegetative bacteria, most viruses, and most fungi but do not necessarily kill bacterial spores. At similar concentrations but with shorter exposure periods (e.g., 12 minutes for 0.55% ortho-phthalaldehyde) these same disinfectants will kill all microorganisms with the exception of large numbers of bacterial spores and are called high-level disinfectants. A few disinfectants will kill spores with prolonged exposure times (e.g., 3 to 12 hours) and are called chemical sterilants. Some of the factors that affect both disinfection and sterilization efficacy are the prior cleaning of the object the organic and inorganic load present the type and level of microbial contamination the concentration of and exposure time to the germicide the nature of the object (e.g., crevices, hinges, and lumens) the presence of biofilms the temperature and pH of the disinfection process and, in some cases, the relative humidity of the sterilization process (e.g., with ETO).īy definition then, disinfection differs from sterilization by its lack of sporicidal property, but this is an oversimplification. The efficacy of disinfection is affected by a number of factors, each of which may nullify or limit the efficacy of the process. Disinfection is usually accomplished by the use of liquid chemicals or wet pasteurization in health care settings. These same germicides used for shorter exposure periods may also be part of the disinfection process (i.e., high-level disinfection).ĭisinfection describes a process that eliminates many or all pathogenic microorganisms on inanimate objects, with the exception of bacterial spores. Unfortunately, some health care professionals as well as the technical and commercial literature refer to “disinfection” as “sterilization” and items as “partially sterile.” When chemicals are used for the purposes of destroying all forms of microbiologic life, including fungal and bacterial spores, they may be called chemical sterilants. Sterilization is intended to convey an absolute meaning, not a relative one. Steam under pressure, dry heat, ethylene oxide (ETO) gas, hydrogen peroxide gas plasma, vaporized hydrogen peroxide, and liquid chemicals are the principal sterilizing agents used in health care facilities. Sterilization is the complete elimination or destruction of all forms of microbial life and is accomplished in health care facilities by either physical or chemical processes. In addition, we briefly review the management of medical waste in health care facilities.

#Chapter 16 blood borne parhogens and principles of asepsis update

2, 4, 5, 6, 7, 8 In this chapter, which is an update of previous chapters, 9, 10, 11, 12, 13 a pragmatic approach to the judicious selection and proper use of disinfection and sterilization processes is presented, based on well-designed studies assessing the efficacy (via laboratory investigations) and effectiveness (via clinical studies) of disinfection and sterilization procedures. 3, 4 Failure to comply with scientifically based guidelines has led to numerous outbreaks of infectious diseases. Multiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization. Because it is unnecessary to sterilize all patient care items, health care policies must identify whether cleaning, disinfection, or sterilization is indicated based primarily on the item's intended use.

Failure to properly disinfect or sterilize equipment carries not only the risk associated with breach of the host barriers but also the additional risk for person-to-person transmission (e.g., hepatitis B virus) and transmission of environmental pathogens (e.g., Clostridium difficile).Īchieving disinfection and sterilization through the use of disinfectants and sterilization practices is essential for ensuring that medical and surgical instruments do not transmit infectious pathogens to patients. A major risk of all such procedures is the introduction of infection. 2 Each of these procedures involves contact by a medical device or surgical instrument with a patient's sterile tissue or mucous membranes.

1 For example, there are at least 10 million gastrointestinal endoscopies per year.

Each year in the United States there are approximately 53 million outpatient surgical procedures and 46 million inpatient surgical procedures.