Infection Control: Asepsis

ANES 1501

Introduction to Anesthesia Technology

College of DuPage

Flora

Microorganisms that occur or have adapted to live in a specific environment.

Two types: Resident (always present)

Transient (episodic)

Virulence

Definition: The frequency with which a pathogen causes disease.

Factors affecting virulence include: Strength of pathogen to adhere to healthy cells.

Ability of pathogen to damage cells or interfere with the body’s normal regulating systems.

Ability of pathogen to evade attach of white blood cells.

Pathogens

Pathogens

Microorganisms that cause disease These include:

Bacteria

Fungi

Viruses

Protozoa

Rickettsia

Bacteria

Small, one-celled microorganisms that lack a true nucleus or mechanism to provide metabolism

Only small percent of bacteria are pathogenic Common bacterial infections include diarrhea,

pneumonia, gonorrhea, meningitis, impetigo, and urinary tract infections.

Viruses

Organisms that live only inside cells. They cannot get nourishment or reproduce outside

cells. Common viral infections include influenza, measles,

common cold, chickenpox, hepatitis B, genital herpes, and HIV.

Fungi

Grow in single cells, as in yeast, or in colonies, as in molds.

Most are not pathogenic and make up many of the body’s normal flora.

Fungi can cause infections of the hair, skin, nails, and mucous membranes.

Protozoa

Single-celled parasitic organisms with the ability to move.

Common protozoan infections include malaria, gastroenteritis, and vaginal infections.

Rickettsia

Intracellular parasites that need to be in living cells to reproduce.

Spread through fleas, ticks, mites, and lice. Common rickettsia infections include typhus, Rocky

Mountain spotted fever, and Lyme disease.

Infection

An invasion and multiplication of pathogenic microorganisms that occurs in body tissue and results in cellular injury.

Chain of Infection

Infectious Agent

Reservoir or Source

Portal of Exit from Reservoir

or Source

Mode of Transmission

Portal of entry to Host

Susceptible Host

Chainof

Infection

Infectious Agent

Definition: An entity capable of causing disease. These may be:

Biological (bacteria, viruses, fungi, protozoa, Rickettsia). Chemical (pesticides, food additives, medications, industrial

chemicals). Physical (environmental factors, like heat, light, noise,

radiation, and machinery).

Reservoir of Source

Definition: A place where the agent can survive. The most common reservoirs are:

Humans

Animals

Environment

Fomites (objects contaminated with an infectious agent, such as bed pans, urinals, linens, instruments, dressings, etc.)

Portal of Exit

Definition: The route by which an infectious agent leaves the reservoir to be transferred to a susceptible host.

These include: Sputum from respiratory tract Semen, vaginal secretions, or urine, from the genito-urinary tract Saliva and feces, from the gastrointestinal tract Blood Draining wounds Tears

Mode of Transmission

Definition: The process that bridges the gap between the portal of exit of the infectious agent from the reservoir or source and the portal of entry of the susceptible “new” host.

These include: Contact transmission (direct contact with infected person, indirect

contact through fomite, or close contact with contaminated secretions)

Airborne transmission Vehicle transmission (through contaminated substances such as

water, milk, drugs, or blood) Vectorborne transmission (through fleas, ticks, lice, and other

animals)

Host

Definition: A simple or complex organism that can be affected by an agent.

A susceptible host lacks resistance to an agent and is vulnerable to disease.

A compromised host has impaired defense mechanisms and is susceptible to infection.

Factors Affecting Susceptibility to Infection

Age Concurrent diseases Stress Immunization and

vaccination status

Occupation Nutritional status Heredity Lifestyle

Breaking the Chain of Infection Between Agent and Reservoir

Cleansing

Disinfection

Sterilization

Cleansing

Definition: The removal of soil or organic material from instruments and equipment.

Four steps:1. Rinsing the object under cold water

2. Applying detergent and scrubbing the object

3. Rinsing the object under warm water

4. Drying the object prior to sterilization or disinfection

Disinfection

Definition: The elimination of pathogens (except spores) from inanimate objects.

Disinfectants are chemical solutions used to clean inanimate objects.

Germicides are chemicals that can be applied to both animate (living) and inanimate objects for the purpose of eliminating pathogens.

Sterilization

Definition: The total elimination of all microorganisms including spores.

Instruments used for invasive procedures must be sterilized.

Moist heat or steam, radiation, chemicals, and ethylene oxide gas used for sterilization.

Autoclaving sterilization, using moist heat, is used in most hospital settings.

Breaking the Chain of Infection

Between reservoir and portal Proper hygiene

Clean dressings

Clean linen

Clean equipment

Breaking the Chain of Infection

Between portal of exit and mode of transmission Clean dressings on all injuries.

Clients should be encouraged to cover the mouth and nose when sneezing or coughing, as should the nurse.

Gloves must be worn whenever necessary.

Proper disposal of contaminated items.

Breaking the Chain of Infection

Between mode of transmission and portal of entry Nurses wearing barrier protection (gloves, masks, gowns,

goggles)

Proper hand-washing

Proper disposal of contaminated equipment and linens

Breaking the Chain of Infection

Between portal of entry and host Maintaining skin integrity

Using sterile technique for client contacts

Avoiding needle sticks

Proper disposal of sharps

Breaking the Chain of Infection

Between host and agent Proper nutrition

Exercise

Immunization

Normal Defense Mechanisms

A host’s immune system serves as a normal defense mechanism against the transmission of infectious agents.

Immune system recognizes presence of antigens, foreign proteins that cause the formation of an antibody.

Nonspecific Immune Defense

Skin and normal flora Mucous membranes Sneezing, coughing, and tearing reflexes Elimination and acidic environment Inflammation

Inflammation

Definition: A nonspecific cellular response to tissue injury.

Characteristics include: Redness (erythema)

Heat

Pain

Swelling (edema)

Loss of function

Pus (purulent exudate)

Specific Immune Defense

Definition: An immune defense mounted specifically against an invading antigen.

Includes: Skin and normal flora

Mucous membranes

Sneezing, coughing, and tearing reflexes

Elimination and acidic environment

Inflammation

Stages of Infection

1. Incubation The time interval between entry of an infectious agent into

host and onset of symptoms.

2. Prodromal Onset of nonspecific symptoms to specific symptoms of

illness

3. Illness Period of specific signs and symptoms of infection.

4. Convalescence From disappearance of acute symptoms until client returns

to previous state of health

Nosocomial Infections

Definition: An infection acquired in a hospital or other health care facility that was not present or incubating at the time of the client’s admission.

Also referred to as hospital-acquired infections.

Asepsis

Definition: The absence of microorganisms. Two types:

1. Medical – Those practices used to reduce the number, growth, and spread of microorganisms.

2. Surgical – Practices that eliminate all microorganisms and spores from an object or area.

Medical Asepsis

Hand-washing is the first line of

defense against infection and is the

single most important practice in

preventing the spread of disease.

Surgical Asepsis Techniques

Surgical hand-washing Sterile field and equipment Donning surgical attire Donning sterile gloves Gowning and closed gloving Disposal of infectious materials