Disinfection And Disease Control

Front 1

Terminology: Asepsis

Back 1

Condition of sterility; no living organisms

Front 2

Terminology: Sterilization

Back 2

Destruction of all organisms and spores; inanimate objects

Front 3

Terminology: Sanitization

Back 3

Making or the quality of being made sanitary; promoting health; clean

Front 4

Chemical Disinfection: Disinfectant

Back 4

- Agent that destroys bacteria or inactivates viruses
- Chemical agents
- Applied to inanimate objects
- Destroys vegetative form of bacteria, not necessarily spores
- Disinfectants that can destroy bacteria, spores, tubercle bacilli, and viruses may be used as chemical sterilizers

Front 5

Disinfection Time

Back 5

- Time required for a particular agent to produce maximal effect
- Influenced by many factors

Front 6

Factors Influencing Disinfection Time

Back 6

1. Nature of material disinfected
2. Degree of soil/microbial contamination
3. Concentration and germicidal potency of disinfectant

Front 7

Antisepsis (Antiseptic)

Back 7

Substance that inhibits the growth and development of microorganisms without killing them
- Used on living tissue

Front 8

Antiseptic and Disinfectant Compounds

Back 8

1. Iodine
2. Chlorhexadine
3. Alcohols
4. Phenols
5. Quaternary Ammonium
6. Chloride
7. Aldehyde

Front 9

Iodine

Back 9

- Antimicrobial agents
- Limited activity against spores
- Used for:
a. Surgical prep
b. Topical wound therapy
c. Joint/body cavity lavage

Front 10

Iodine Compounds: Aqueous Solutions

Back 10

- Higher levels of free iodine
- Greater bactericidal activity
- Do not use on tissue unless greatly diluted

Front 11

Iodine Compounds: Tincture of Iodine

Back 11

- 2% iodine, 50% ethyl alcohol
- Use on intact skin, not common vet use

Front 12

Iodine Compounds: Iodphors

Back 12

- Free iodine slowly released
- Staining/irritation is reduced
- Delivery of iodine to tissue is enhanced
- Povidone-iodine

Front 13

Povidone-Iodine

Back 13

- Most common iodophore in vet offices
a. Skin irritation
b. Acute contact dermatitis (50% of canines)
c. Staff infection
- Scrubs or solutions
- Dilution of solutions increase bactericidal activity and decrease cytotoxicity
- Residual activity (continued action when left on skin) is 4-6 hours
a. Diminished in presence of organic matter (blood), alcohol

Front 14

Chlorhexadine

Back 14

- Antiseptic agent
- Non-irritating to skin
- Rapid onset, long residual activity (2 days) not affected by alcohol/organic debris
- Surgical scrub/solution
- Aqueous, tincture and detergent formulas
- Effective antimicrobial
a. Bacteria
b. Molds
c. Yeasts
d. Viruses
- Lavage solution for open wounds
a. Diluted 1:40 with sterile water or saline
b. Higher concentrations can cause inflammation and cytotoxicity
c. Will precipitate when mixed with electrolyte solutions (i.e. LRS)

Front 15

Alcohols

Back 15

- Disinfectants and antiseptics
- Organic solvents
- Evaporate rapidly
- No residue
- Bactericidal, ineffective against spores/fungi
- No residual effect, inactivated by organic debris
- Ethyl and isopropyl are more effective than methyl as disinfectants

Front 16

Phenols

Back 16

- Carbolic acid
- Antiseptic and disinfectant
- Residual activity = up to 2 days
- Toxic to cats
- Replaced by newer, safer, more effective agents
a. Hexachlorophene

Front 17

Quaternary Ammoniums

Back 17

- Roccal, Mint Quat
a. Good deoderant actions
- Synthetic cationic detergents
- Act on cell membranes
- Effective against bacteria, not spores, some viruses
- Bland, nontoxic
- Non-corrosive to instruments
- Benzalkonium chloride
a. Common disinfectant

Front 18

Chloride

Back 18

- Excellent, fast-acting, low in cost
- 1:32 dilution
- Bactericidal, virucidal, fungicidal, and tuberculocidal
- Cytotoxic
- Skin irritants
- Unstable
- Corrosive to instruments
- Ineffective in the presence of organic contaminants
- Toxic to cats

Front 19

Aldehydes

Back 19

1. Formaldehyde
2. Glutaraldehydes

Front 20

Formaldehyde

Back 20

- Toxic, irritating
- Do not use on living tissue
- Effective, several hours of exposure
- Tissue preservation

Front 21

Glutaraldehydes

Back 21

- Cidex
- Agent of choice for cold sterilization
- Bacteria, virus, fungi, yeast, spores
- Not inactivated by organic debris
- Have a short shelf life

Front 22

Oxidizing Agents

Back 22

- Used to remove dead, necrotic, or injured tissue
- Kills bacteria

Front 23

Oxidizing Agents: Hydrogen Peroxide (H2O2)

Back 23

- Releases oxygen to kill anaerobic bacteria in wounds
- Used in a 3% solution
- Not virucidal
- May damage healthy or viable tissue
- Hemolyzes RBC's to clean blood from animal fur
- Very effective emetic in dogs

Front 24

Detergents and Soaps

Back 24

- Anionic compounds
- Mildly effective antibacterials
- Effective in the mechanical removal or organisms
- Contain germicides to decrease the number of microbes after washing

Front 25

Acids/Alkalis

Back 25

- Work by creating a pH incompatible with the contaminant

Front 26

Acids

Back 26

Boric, nalidixic, and acetic (used in .25% solution, particularly effective against Pseudomonas)

Front 27

Alkalis

Back 27

Lye, quicklime (excellent for disinfecting stables and premises)

Front 28

Nitrofurans

Back 28

- Furacine is frequently used to treat superficial wounds
- Also used to flush surgical wounds in a more dilute solution

Front 29

Cold Sterilization

Back 29

- Soaking instruments in disinfecting solutions
- Chlorhexadine, glutaraldehyde
- Cold trays
a. Exposure time = longer than 3 hours
b. Rinse before use
- Not sterile
a. Superficial lacerations, endoscopy equipment, dental procedures

Front 30

Factors Influencing Use of AntiInfectives

Back 30

- Purpose for use (READ DIRECTIONS)
- Water quality: some will not work with hard water and some are pH dependent
- Water temp: the hotter the water the better
a. 180 degrees F is optimal
- How long the compound is left on the applied surface
a. 10 minutes before rinsing

Front 31

Methods of Physical Sterilization

Back 31

1. Filtration
2. Radiation
3. Heat

Front 32

Filtration

Back 32

- Use of a filter to separate particular material from liquids or gases
- Pharmaceuticals

Front 33

Radiation

Back 33

- Destroys microorganisms without temperature elevation
- Gloves, suture materials

Front 34

Heat

Back 34

- Most common
- Death occurs by protein denaturation
- Most effective way to kill microorganisms
- Will even kill spores (requires longer sterilization time)
- Types:
a. Moist heat (most effective)
b. Dry heat

Front 35

Moist Heat

Back 35

- Boiling water
a. Not reliable
b. Dulls instruments
c. Probably results in disinfection
- Steam under pressure
a. Pressure causes steam to achieve higher temp
b. Autoclaves: moist packs = contamination; no water = scorched packs