CHAPTER 12: INFECTION CONTROL

Learning Goals:

Understand principles of infection control are essential to all healthcare workers

Provide a basic knowledge of how disease is transmitted Main emphasis on prevention of disease

Understanding the Principles of Infection Control

Microbes – small living organisms Invisible to the naked eye Microscope must be used to see them Found everywhere in the environment Found on and in the human bodyMany are part of the normal Flora of bodyMay be beneficial in maintaining body processes

Flora – plant life for living in a specific environment

Microorganisms or Microbes

Called non-pathogens when not harmful to the body

Some cause infections and disease

Called pathogens (germs) when able to harm the body

Sometimes non-pathogenic microorganisms can become pathogenic

Microorganisms or Microbes (continued)

Bacteria Protozoa Fungi Rickettsiae Viruses

Microbe Classifications

Simple one celled organism Multiply rapidly Classified by shape and arrangement

Bacteria

Round or spherical in shape Diplococcic (pairs of cocci)

Gonorrhea, meningitis, pneumonia Streptococci (chain of cocci)

Strep throat, rheumatic fever Staphylococci (clusters, or groups of cocci)

Boils, wound infections, toxic shock Pus producing

Bacteria - Cocci

Rod Shaped Occur singly, in pairs or in chains May have flagella (tail-like)

Projections that allow it to move Ability to form spores

Ex: TB, tetanus, whooping cough, typhoid

Bacteria - Bacilli

Spiral or corkscrew shape Includes comma-shaped vibrio and corkscrew spirochete Disease include syphilis and cholera (Vibrio- common in food borne infection, eating under cooked

seafood)

Bacteria - Spirilla

Used to kill bacteria Some strains of bacteria have become anti-biotic resistant When anti-biotic resistant, the antibiotic is no longer effective against

the bacteria

Antibiotics

One celled, animal like organism Found in decayed materials and contaminated water May have flagella for movement Some are pathogenic (infectious agent leading to sickness in host)

Protozoa

Simple plant like organism Live on dead and organic matter Yeast and molds Can be pathogenic Antibiotics do not kill Antifungal medications Athlete’s foot, yeast infections

Fungi

Parasitic Microorganisms Can not live outside cells of another organism Transmitted to humans by the bites of insects (ie: fleas, lice, ticks, mites) Antibiotics are effective against them Typhus fever, Rocky mountain spotted fever - tick borne disease that can be

fatal in humans

Rickettsiae

Smallest of microorganism Must use electron microscope to see Must be inside another living cell to reproduce Spread human to human by blood or body secretions Difficult to kill

Don’t respond to antibiotics Resistant to disinfectants

Cause many diseases in humans – Hepatitis & AIDS

Viruses

Ideal environment: warm, dark, moist Need source of food and moisture Need for oxygen varies Human body is ideal supplier of all requirements

Growth of Microorganisms

Some produce poisons called toxins

Some cause allergic reactions Others attack and destroy the

living cells they invade

How Pathogens Cause Classifications ofInfection and Disease Diseases and Infections

Endogenous – originates inside body Exogenous – originates outside of body Nosocomial – Infection inquired in Healthcare

facility Opportunistic – Infections that occur when

the body’s immunity is suppressed or weak

Chain of infection

1. Causative (Infectious) agent Pathogen must be present Examples include bacteria

2. Reservoir Place where causative agent can live Examples: human body, animals and the environment

3. Portal of Exit Way for causative agent to escape from the reservoir Examples: urine, feces, saliva, blood, tears, mucous discharge, sexual secretions

and draining wounds

Chain of Infection …

4. Mode of Transmission Must be transmitted to another reservoir or host where it can live Direct Contact: spread by physical (hands) or sexual contact Indirect Contact: from contaminated substances to the person (food,

air droplets, insects, clothing, instruments

5. Portal of Entry Way to enter a new reservoir or host Examples: breaks in skin or mucous membranes, respiratory tract,

circulatory system, genitourinary tract

Chain of Infection …

6. Susceptible Host Individual who can contract the disease If a larger number of pathogens invade the body or the body defenses

are weak, then the individual (susceptible host) can become sick with infection or disease

If any part of the chain of infection is broken, the spread of disease or infection can be stopped

Chain of Infection …

Mucous Membranes Cilia Coughing & Sneezing HCL (hydrochloric acid) in stomach Tears Fever Inflammation response – leukocytes Immune response – antibodies and cell secretion

Common Body Defenses

Eliminate any step in the chain of infection Follow standard practices to interrupt or break chain Remember pathogens are everywhere Prevention is a continuous process

Ending the Chain of Infection

Major way to break the chain of infection Asepsis: absence of disease-producing microorganisms or pathogens Contaminated: any object or area that may contain pathogens Major Goal: maintaining cleanliness and eliminating or preventing

contaminations

Aseptic Techniques

Hand Washing Good personal Hygiene Disposable gloves Proper cleaning of instruments and equipment Thorough cleaning of environment

Common Aseptic Techniques

Prevent or slow growth of pathogenic organisms Not effective against spores and viruses Used on skin Examples: Alcohol and betadine

Aseptic Control: Antisepsis

Destroys or kills pathogenic organisms Not always effective Chemical disinfectants are used Can irritate or damage skin

Used on objects not people Examples : Bleach solution

Aseptic Control: Disinfection

Destroys all microorganisms Steam under pressure, gas radiation and chemicals Autoclave is the most common

Aseptic Control: Sterilization

Important for healthcare workers to know and use proper aseptic techniques

Prevents spread and transmission of diseases

Summary