Today is our topic of discussion Sterilization and disinfection
Sterilization and disinfection
Disinfectant:
A ‘disinfectant’ or germicide is a substance which destroys usually spores) with the object of preventing transmission of disease. Disinfectants are suitable for application only to inanimate objects.
Disinfection:
Disinfection is the killing of infectious agents outside the body by direct exposure to chemical or physical agents.
Levels of disinfection:
High-level disinfection:
May kill all microorganisms but not all bacterial spores; achieved after thorough detergent cleaning, by exposure to specific concentrations of certain disinfectants (e.g., 2% glutaraldehyde, 6% stabilized hydrogen peroxide etc.) for at least 20 minutes.
Intermediate-level disinfection:
It does not kill spores; it can be achieved by pasteurization (temperature holding at 72°C for not less than 15 seconds and rapidly cooled to 4°C).
Types of disinfection:
Concurrent disinfection:
Application of disinfective measures as soon as possible after discharge of infectious material from the body or soiling of articles with infectious discharges,
Terminal disinfection:
Application of disinfective measures after the patient has been removed by death or to hospital or has ceased to be a source of infection or hospital isolation practices have been discontinued.
Prophylactic disinfection:
Disinfection of water by chlorine, pasteurization of milk and handwashing.
Antiseptic:
An antiseptic is a substance which destroys or inhibits the growth of microorganisms. Antiseptics are suitable for application to living tissue. A disinfectant in low concentrations or dilutions can act as an antiseptic.
Deodorant:
A deodorant is a substance which suppresses or neutralizes bad odours, e.g., lime and bleaching powder.
Detergent:
A detergent is surface cleaning agent which acts by lowering surface tension, e.g., soap which removes bacteria along with dirts.
Sterilization:
Sterilization is the process by which all viable micro-organisms including spores are killed or eliminated.
Methods of disinfection and sterilization:
Natural agents:
Sunlight and air
Physical agents-
a. Burning
b. Hor air oven
c. Boiling
d. Autoclaving
e. Filtration
Chemical agents:
a. Alcohols
b. Phenols
c. Heavy metals
d. Dyes
e. Detergents
f. Ethylene oxide
g. Oxidizing agents
h. Halogens, formaldehyde, chlorine gas, gluteraldehyde etc.
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