Principles of Epidemiology and Microbiology
Lesson 3: Practical Application of Microbiology
Section II: Disinfection and Sterilization
3-3
Section II. DISINFECTION AND STERILIZATION
3-3. GENERAL
Disinfection and sterilization are indispensable procedures in modern medicine and public health. Without the benefit of these procedures, it would be virtually impossible to carry out many of the routine surgical procedures that are often taken for granted. It would also be impossible to isolate specific microorganisms for their study.
a. Definitions.
(1) Disinfection is the destruction of pathogenic organisms. It does not necessarily include the killing of all microbes. A disinfectant is any agent capable of destroying pathogenic microorganisms.
(2) Sterilization is the elimination of all living microorganisms, both pathogenic and harmless. Any object or material free of all microorganisms is referred to as sterile.
(3) Antiseptics are agents which prevent the multiplication of microorganisms but which do not necessarily kill them.
(4) Germicides (bactericides) are agents causing the destruction of microorganisms, both pathogenic and harmless.
(5) Asepsis is the absence of pathogenic microorganisms from a given object or area.
(6) Contamination is the presence of living microorganisms rendering an object or material unfit for its intended use.
(7) Bacteriostasis (virustasis) is the condition by which microorganisms are prevented from multiplying, but in no other way affected.
(8) Sanitization is the reduction in the number of bacteria to a level prescribed as safe by public health or environmental health authorities.
b. Types of Agents. Agents for sterilizing and disinfecting may be classified as physical and chemical agents. Specific agents are discussed in paragraphs 3-4 and 3-5.
